Posted by Frank H. Reynolds on March 01, 2001 at 09:11:50
I started with a RS DX398. The signals are out there, just difficult to get.
I wasn't able to copy a Lowfer until I upgraded quite a bit of equipment. I too have copied ZWI (from Rome, NY). No luck with any others. I've tried making some loops without success. I now have a 625 ft beverage what works well. I have used it primarily for NDBs.
You will need some large varible capacitors to build a loop that will tune much of a band, Antique Electronic Supply has a 3 gang 500 pf.
good luck Frank KC2FDW
Wanted- Information AC & DC Powerline Carrier Communications
Posted by Frank J. Lotito on March 01, 2001 at 12:09:22
I am a column editor for the OTB, The Old Timer's Bulletin, the quarterly publication of the Antique Wireless Association. The column is titled "Below 535." I am looking for a volunteer to write an applied technology article about LF power line carrier communications techniques, past and present. If no volunteers, I would appreciate suggestions on applicable literature and Internet sources that discuss this topic.
I am most interested in an article / information regarding the past and present techniques used by utility companies and certain industries, i.e., underground mining. In these applications the AC or DC power lines are used to convey voice and / or data on a NBFM modulated LF carrier.
As column editor, I am available to assist potential authors in writing and researching this article.
Thank you, Frank J. Lotito, K3DZ e-mail k3dz@aol.com
Lowfer LEA down for season
Posted by Michael Reed on March 01, 2001 at 19:31:38
Well, I probably won't have LEA 184324.1 on for some time. Too much school work. If you still want to know, grid square is CN84lw. I do plan on using QRSS when it is on, hopefully WOLF too. I have all the good parts - the 53/33 litz from www.sciplus.com, a telescoping 50' tower, an old computer - but I probably can't work on anything till spring break.
Thanks for listing me while I was on. I will write back when I'm on the air.
Mick Reed reedmi@engr.orst.edu Salem, OR
Re: Antenna loading coil
Posted by Frank J. Lotito on March 01, 2001 at 19:39:48
Suggest you try to model your antenna using ELNEC or EZNEC. Then looking at the base impedance at the frequency you want to operate on, you can plug in a base inductor that cancles the antenna's capacitive reactance. Rerun the analysis and see if the base impedance is resistive plus a negligible reactance at your chosen frequency. If not trim accordingly.
In the modeling above you can also include the effect of the Q (estimated) of your base and center loading colis. This is done by including a series resistor with each coil. The resistor value is the coil's inductive reactance divided by the estimated Q.
The above is only an approximation, but gets you in the ball park. You can also see how the model's design effects the all important radiation resistance.
The LWCA web site, and links contain base loading coil designs reported to give Q's around 400.
Have fun - 73's K3DZ
Re: Antenna loading coil
Posted by Robert Bicking on March 01, 2001 at 22:04:45
If you have an antenna analyzer such as Autek or MFJ or can borrow one, my article in the Oct. 99 Lowdown gives a method which I used to determine the coil size. It also gives details on winding the coil and where to get Litz wire. The article is also on my website www.qsl.net/w9rb/
A small coil with an adjustable ferrite core is the simplest but wastes a lot of power (and with only 1 watt to play with, you don't want to waste power).
Fwd: (Stewart Nelson) XMGR received near Reno; new WOLF version
Posted by John Davis on March 02, 2001 at 09:31:05
Hi Les and all,
I added a few new features to WOLF to help deal with receiver drift, static crashes, not knowing whether you have a signal, etc. Details and software are at http://www.scgroup.com/ham/wolf.html .
After a great deal of parameter tweaking:
C:\wolf>wolf -q xmgr.wav -f 805.495 -t .1 -w -.0000046 -r 8000.06
-b 14000 -s 9984000 WOLF version 0.51 t: 24 f: 0.057 a: 1.2 dp: 88.7 ci:15 cj: 61 0JH/C20YSHKXC0 ?
t: 48 f: 0.058 a: 1.1 dp: 85.5 ci:14 cj: 87 .Z9D.DEZNM1TCH ?
t: 96 f:-0.048 a: 0.1 dp: 83.5 ci:13 cj:103 OBW06/HCF6ZIRN ?
t: 192 f:-0.010 pm: 25 jm:564 3AWPM9KTBE7*4QU ?
t: 288 f: 0.000 pm: 38 jm:564 DE XM XM XM -
t: 384 f: 0.000 pm: 38 jm:564 8DW.QNMSE//9GVS ?
t: 480 f:-0.010 pm: 38 jm:564 G2.F208A245014L ?
t: 576 f: 0.000 pm: 56 jm:565 JFA9ES5389RS/OA ?
I must confess that my receiver drift measured at about 46 uHz/sec., but I made a typo and entered 4.6 instead. The result was correct copy!
It's about 1875 miles from my 39.34N, 119.79W location to EM63oh.
73,
Stewart KK7KA
Re: Earth field detector
Posted by Frank Carson on March 02, 2001 at 10:55:53
I read your post - interesting. However, how can you prove that,
instead of a field detector, you didn't make an inexpensive and very sensitive seismometer (which, in itself, is really cool as well!)? How is the device isolated from vibrations (both the detector and laser)? I have a "geophone" that cost $10 (they are used to detect oil and water at the end of a drilled hole). It is unbelievably sensitive. Hooked up to an oscilliscope it can literally detect a pin dropped on the test bench.
Anyway, I want to build your device (which does sound fun, no matter what it detects!) and give it a try.
Thanks!
Frank Carson
Re: Fwd: (Stewart Nelson) XMGR received near Reno; new WOLF version
Posted by Mick Reed on March 02, 2001 at 12:54:33
Hey, Les! I guess you were right about the possibility of receiving LEA in Oregon next season... I didn't know that WOLF had such potential. Hopefully someone can get a QSO going from East to West coast!
Improving antenna
Posted by Donald R. Moler on March 02, 2001 at 14:16:34
I am in the process of installing a new super efficent antenna for 1750 meters. I just took the fiberglass mold that I built out of redwood for the loading coil to the fiberglass shop and was told it would be ready Monday. The coil form is about 36 inches in diameter by 36 inches high and will be wound with half inch copper strap. This loading coil will be mounted on top of a 30 foot tower. The tower will have a 40 foot diameter top hat made from eight one and a quarter inch thin wall aluminum tubing. The radial system will be made of wire fence, 2X4 inch openings, and cover the entire ground. I will need some help putting this thing up in a few weeks so if anyone can help let me know. I have a question ... The formula for skin depth for copper is; cm = 6.62 divided by the square root of the frequency. I would like to know if it is worth the improvment in effciency to silver plate the copper strap used on the loading coil ?
VA off for the season
Posted by Bart Prater on March 02, 2001 at 19:12:15
Just spotted the "first Mercedes of spring" at one of the numerous vacation homes here on Smith Mountain Lake, Virginia. A sure sign the thunderstorms are on their way. So, lowfer VA is off for the season. Thanks for the reports, see you in October.
73,
Bart
Pacific Northwest LOWFERS?
Posted by Steve McDonald on March 03, 2001 at 19:51:45
Are there presently any active LOWFER beacons running in Washington, Oregon, N. Calif, Idaho??
Steve / VE7SL
Re: Pacific Northwest LOWFERS?
Posted by Donald R. Moler on March 03, 2001 at 22:29:21
There is one station that is getting ready to go on line in Missoula Montana. His ham call is W7KBF
Don Moler Vonj@cboss.com
Re: Pacific Northwest LOWFERS?
Posted by Mick Reed on March 03, 2001 at 22:31:31
Well, I had a really weak setup going for about a month, LEA on 184324.1 Hz. I am in Salem, OR. I am not a ham, but a student in electrical engineering at OSU. I have taken that down and hope to be back on the air in one month. My new setup is a telescoping tower which goes as much as 50 feet high. I haven't made the tophat yet, still thinking about that. I have got some wire which is 21 strands of 33 for my coil. My Class E power amp is unkinked and ready. So far I have used only CW, but I plan to go to QRSS(S) and WOLF as I have a spare PC now.
Beware of Litz wire at www.sciplus.com
Posted by Mick Reed on March 03, 2001 at 22:37:40
I ordered some of the Litz wire from www.sciplus.com. Please note! The wire they have IS NOT advertised right! They claim to have some 53/33 and 43/33. We know this to mean 53 strands of 33 guage, or 43 strands of 33 guage. WHat they are selling for the 53/33 is actually 7 strands of (33?) guage. I don't think they are trying to rip anyone off, I'll bet it is an honest mistake. Just know what you are getting. They respond well to emails if you have questions.
73s Mick
contributor omission
Posted by Dick Pearce on March 03, 2001 at 23:38:50
Hi all, my apologies for omitting AR-MI from the contributor list in the March DX Downstairs column. He's Andy Robins, 1529 Miles Avenue, Kalamazoo, Mi. 49001. andrew.robins@wmic Yeasu FRG100, homebrew 34" loop and MFJ 752c audio filter. 73s Dick
Greetings!
Posted by Bill, KD0HG on March 04, 2001 at 12:58:26
I recently wound down the six month project of overhauling a 1954 Collins R-389...Exposed to moisture at one time, this was a major ordeal, having to completely rebuild the complex mechanics of the front end and its 40-odd ball bearing assemblies. When I first got it, it was a frozen, rusty relic- Now it can be tuned with a single finger on the knob. Anyway, after only a few days of listening on an 900' E-W Beverage, I must say as a newbie I'm astonished at the ground wave coverage of the utes and NDBs I've heard- From my location near Loveland, Colorado I've logged NDBs over a thousand miles away- during the day- from as far as central Ontario. As a broadcast engineer I knew that ground wave on VLF/LF was good, but it's astonishing to me how good. One note- I can forget about receiving LOWFER beacons near 180 KHz...the 3rd harmonic of WWVs 60 KHz signal is pretty darn strong here on the Front Range only 25 miles from their site. In any event, it's good to be here, and hopefully I'll be able to receive my first LOWFER transmission at some point- so far, nada.
73,
Bill KD0HG
5 mi S. of Loveland, Colorado Two Easters Ranch
TEXAS received in EN36us
Posted by Bryce Ofstie, KI0LE on March 04, 2001 at 13:30:45
Hi,
Last night I set up on 187.04 and started recording. Like most nights recently, the static was really bad here. I decided to let the recorder keep running over night,
expecting to see that the machine had crashed in the morning. To my surprise it was still running this morning and had saved a 550 Meg wave file. I could see that at about 3:00 in the morning the amplitude of the wave file decreased slightly. I copied a half hour after that point and saved it to another file. Bill's message came through solid after the first 96 seconds. About 990 miles, nice signal Bill.
73, Bryce
BRO sending Wolf 24/7
Posted by Bryce Ofstie, KI0LE on March 04, 2001 at 13:42:46
The results speak for themselves. I programmed up an EEprom for the All-in-One transmitter and I am now sending WOLF. Lets see if I can get a few more reception reports. I had to get the snowshoes out to get to the transmitter. I'll try to post a few pictures on my website later today.
73, Bryce BRO 182.200 kHz Wolf 24/7
XM(GR) Back on in WOLF. Special QSL offered!
Posted by Les Rayburn, N1LF on March 04, 2001 at 15:21:23
After making repairs to the final amp, and loading coil XM(GR) is back on the air 24/7 transmitting in WOLF mode on 184.900khz.
We have also made up special "WOLF MODE" QSL cards that will be sent out to anyone who receives the beacon in this mode. Cards have already been sent to
BRO (976 Mile Reception of XMGR)
Stewart Nelson (1,874 Mile Reception of XMGR)
Hope to send out more cards like this soon!
Re: TEXAS received in EN36us
Posted by Bill Cantrell on March 04, 2001 at 17:41:42
Subj: TEXAS Received in Minnesota at 990 miles Date: 3/4/01 5:14:41 PM Eastern Standard Time From: Bill.Cantrell@motorola.com (Cantrell Bill-QA0057)
To: ki0le@cp.duluth.mn.us ('Bryce Ofstie')
CC: ('LowFER Reflector'), ('LWCA News')
Congratulations to Bryce for copying TEXAS in WOLF mode on 187.040 kHz. The weather has improved down here, and my antenna current looks good right now.
(Bryce, send me your mailing address and I will send you a QSL card!)
Regards,
Bill
"TEXAS" & WD5CVG
187.040 kHz running WOLF mode 24/7
Re: Beware of Litz wire at www.sciplus.com
Posted by Dexter on March 05, 2001 at 09:02:40
I ordered 600 feet and received one 500 foot spool of 48/33 and a 100 foot loose length of 62/33. Looks like they send what ever they have that looks like litz wire. Although I came out fairly well with what I got, 48/33 or 62/33 still isn't really that great for LF from what I have been told.
Dexter
free transformers
Posted by don moler on March 05, 2001 at 17:04:54
At one time I worked for a nondestrutive testing company that tested mostly steel tubes for defects using eddy current at frequencys from 60 cycles to MHZ. Some of the older equipment used wideband transformers in the front end that had no measureable amount of flux leakage and are closed cores with mu metal sheilding. These transformers measure about one inch by one and a half inchs. I don't have the specs on them but they work very well at 180 khz and below. They have two windings and one of the windings is center tapped. They can be taken apart and rewound to your likes. There is a plastic bobbin inside that makes it easy to wind your own. I asked if I could have some of these transformers and the company gave me six. So if any one wants one,(FREE!!) just send me a SASE or a small box (at least 3X3 inchs) and I will send you one.....I will be able to get more at a later date. I may also be able to get some phase shifters to give away. Don Moler 2623 Morris Lane Girard, Ohio 44420 330-530-2059 Vonj@cboss.com
RSGB Low Frequency Experimenters Handbook
Posted by Robert Bicking on March 05, 2001 at 23:40:41
I ordered a copy of the subject book through the link given on this web page and found it quite interesting. It is nicely done, like an ARRL handbook and more polished in appearance than the earlier RSGB LF Scrapbooks. The chapters cover Receivers, Transmitters, LF Antennas and Coils (including a copy of a Lowdown article by Bill Bowers), Specialist Techniques (QRSS, etc.), Test Equipment and several appendices. Interference from high power LF AM broadcasters is one of the issues faced in Europe and several interference cancelling circuits are described. One of the appendices is a reprint of a 1922 paper by a Dr. of Engineering with Telefunken on ground systems for low frequency antennas. Interestingly, the paper mentions the great expense involved to achieve a low resistance ground system. Deja Vu!
BRO heard at 820 miles out.
Posted by Bryce Ofstie, KI0LE on March 06, 2001 at 17:14:19
Hi,
John Andrews sent me a listing from WOLF that contained enough of my message (complete call and most of the location) to convince me that my beacon is getting out in WOLF.
Congratulations to John for being the furthest reception report I have gotten so far. Lets see who else can 'hear' me now.
73,
Bryce BRO 182.2 kHz
Re: BRO heard at 1052 miles out.
Posted by John Andrews on March 06, 2001 at 18:43:19
Bryce,
It's actually 1052 miles - an error in transcribing my grid square was responsible for the lower figure.
John Andrews
1055 Miles actually.
Posted by Bryce Ofstie on March 06, 2001 at 18:56:59
John pointed out that I transposed the digits in the grid coordinates and the distance is actually 1055 miles. Even better, nice work John.
73, Bryce
Re: BRO heard at 820 miles out.
Posted by Les Rayburn, N1LF on March 06, 2001 at 23:37:36
Congratulations to Bryce and John! I know how satisfying it can be to work on a beacon and then be heard at a great distance...welcome to the 1,000 mile club Bryce!
73,
Les
Re: "RB" Beacon on QRSS
Posted by Joe Mann on March 07, 2001 at 01:17:13
Rob,
I am currently (0300Z) copying your RB qrss transmissions at s1 in EN61dm, dashes @ 17 sec and dits @ 6 sec. I am able to copy your signal most every evening. I've spent most of this season chasing NDBs, with only you and BOB being heard at this location.
I'm using 4 loop K9AY/preamp /TR-7 / DATONG FL-1 / FFT software.
Continued success, Joe, K9HDE
Survey Says...
Posted by webmaster on March 07, 2001 at 01:20:31
Even though we had our recent survey up for only a little over 24 hours, the readers were unanimous and enthusiastic --"give us a separate window to open messages into."
So, that's exactly what we'll do. Unfortunately, there will be a slight delay in implementing the feature.
When tested Tuesday evening, the code to create the separate window worked perfectly. But the change makes new posts invisible to the board administration software!
In returning to the original software, yours truly took one step out of sequence, and ended up wiping the message list entirely, along with the most recent backup! A 5-day-old backup was available, but it's going to take a few days to get all the recent posts to display correctly again, as many of them were part of message threads. The code on those really adds up, and is prone to error when done manually.
Once that task is complete, we can then move on to patching the administration software, thereby enabling the separate window.
Thanks, everyone, for your opinions and feedback!
John Davis
TEXAS wolfed in MA!
Posted by John Andrews on March 07, 2001 at 09:03:45
Bill Cantrell's TEXAS was beautifully received in Central MA this morning around 0815Z. This is after MANY hours of recording and analyzing his WOLF transmissions. I got seven lines of clean copy in the half hour from 0800 to 0830Z. Have not yet had time to look at all of the 3 hour recording, but the 0830 to 0900Z half hour had no useful signal.
Distance is 1532 miles.
Thanks to Bill for QSY'ing to 187.04. His previous frequency of 189.09 kHz was a problem here in the NE, due to the Iceland station on 189.0. It was also a big help to know that TEXAS was on frequency -- turned out to be only 10 milliHertz from where I had my receiver calibrated!
John Andrews, W1TAG
What's a good place to buy a TCXO?
Posted by Mick Reed on March 07, 2001 at 13:04:04
When I hear people talking about stability, I figure they are using TCXOs. Could someone reply with where is an inexpensive place to get them? Has anyone sampled them from manufacturers before? Thanks.
Racal VLF converter 337 FS
Posted by Matt Stutterheim on March 07, 2001 at 13:08:05
For sale, Racal VLF converter model 337, complete except front panel & knobs. Covers from 3 kHz to 980 kHz, upconverting to the 2-3 or 3-4 Mhz band (I forget which) but inverted. No book, but might be available on Racal webpage. Some really high quality coils and components inside. Mu metal case. About 1.5" hi, 6" wide, and 20" deep.
Requires -16v and 1 Mhz reference source. Range is divided into six bands. Bought new from factory 15 years ago, never used.
Want $135 + shipping.
Medfer NC 510.500 khz now Wolfing!
Posted by Dexter, W4DEX on March 07, 2001 at 16:20:18
Medfer NC on 510.500 khz is now transmitting in Wolf mode. I was able to decode the signal received at the house shack so I assume it is keying properly. It will be in Wolf mode until further notice.
Lowfer NC 177.777 is QRT, probably for the season. Even if the coil hadn't blown off the building a few weeks ago it probably would have yesterday. I have never seen the wind blow so hard for so long as it did on this little hill top.
Dexter
Re: Several questions from LW novice...
Posted by Frank Reynolds, KC2FDW on March 08, 2001 at 07:22:03
Think about an upverter. The Palomar is about $90, jumps 12 - 500 kHz up to 4 MHz where the lower priced receivers can hear better.
I also use it on my Drake R8A to get lower than 100kHz. (Set the clocks with WWVB @ 60 kHz.)
TEXAS WOLFING IN ALABAMA!
Posted by Les Rayburn, N1LF on March 08, 2001 at 08:47:19
Got quite a treat this morning with a file I recorded just before dawn local time...WOLF is amazing!
C:\Wolf>wolf -q tx3.wav -f 788 -r 8002.3 WOLF version 0.51 t: 24 f: 0.616 a: 1.2 dp:100.3 ci: 4 cj:105 KU4ZD/3A02FODBQ ?
t: 48 f:-0.001 a: 0.7 dp: 97.8 ci: 4 cj:383 /WFGPMA/T???9K/ ?
t: 96 f: 0.502 a: 0.4 dp: 95.4 ci:14 cj:379 KCFWHQD 4.G/9OQ ?
t: 192 f: 0.361 pm: 105 jm:901 T7I9436FG85NH6Z ?
t: 288 f: 0.361 pm: 116 jm:901 SNO6W56HJPVCWS7 ?
t: 384 f: 0.498 pm: 134 jm: 56 .U5E.6GE.LK8T.I -
t: 480 f:-0.498 pm: 157 jm:954 TEXAS AGGIE 79 -
t: 576 f:-0.498 pm: 209 jm:954 TEXAS AGGIE 79 -
t: 672 f:-0.498 pm: 268 jm:954 TEXAS AGGIE 79 -
t: 768 f:-0.498 pm: 314 jm:954 TEXAS AGGIE 79 -
t: 864 f:-0.508 pm: 343 jm:954 TEXAS AGGIE 79 -
t: 960 f:-0.508 pm: 360 jm:954 TEXAS AGGIE 79 -
t:1056 f:-0.498 pm: 447 jm:954 TEXAS AGGIE 79 -
t:1152 f:-0.498 pm: 510 jm:954 TEXAS AGGIE 79 -
t:1248 f:-0.498 pm: 532 jm:954 TEXAS AGGIE 79 -
t:1344 f:-0.498 pm: 563 jm:954 TEXAS AGGIE 79 -
t:1440 f:-0.498 pm: 587 jm:954 TEXAS AGGIE 79 -
t:1536 f:-0.498 pm: 599 jm:954 TEXAS AGGIE 79 -
Long Wave Beacon Directory- Where can i find one?
Posted by John Mallery on March 09, 2001 at 13:52:57
Looking for a directory on the web or in book form. Just fired up my old Lf loop and cannot ident some beacons including marker beacons. Please email:jmallery@kc.rr.com Thanks. John
Beacon RM
Posted by Roger Magnuson on March 09, 2001 at 21:45:03
Hi all,
My beacon, (RM 189.8) is still on the air with no plans to shut down for the season. I am currently sending CW 12 wpm and QRSS10. No wolf mode yet .Hoping that some listeners out there are still willing and able to look for the almost forgotten but still effective QRSS mode!! Good luck Bill (WA) with your loop repair. I'm hoping to do some experiments with transmitting loops this summer too. Your efforts are very encouraging and it sure was fun to see (WA) scrolling across my screen many nights. Thanks to all LOWFERS for a great season.
Roger, (RM 189.8)
Re: Long Wave Beacon Directory- Where can i find one?
Posted by Clint Turner KA7OEI on March 10, 2001 at 00:12:42
One good place is AirNav's online NavAid database. This may be found at:
http://www.airnav.com/navaids/
Clint
Locations
Posted by Rye Gewalt on March 10, 2001 at 05:29:21
It would be helpful to some of us new fellers if messages included sender locations as part of the signatures. While it is nice to hear that AB heard XY, without locations it's kind of quizzical to us newbies.
Rye Springfield, VA
Re: Locations
Posted by John Davis on March 10, 2001 at 14:46:04
I think the reason most of the guys don't mention locations is because they are so readily available online. At the lwca.org home page, click the LowFER/MedFER link and select "who's on the air." Locations are listed by city, and even by six-character grid squares where available. The same information is also available through a link at Les Rayburn's Noise Floor page.
It can be very handy to have those locations marked in the Bookmarks or Favorites list in your Web browser.
73,
John
TEXAS to QSY to 189.700 kHz
Posted by Bill Cantrell on March 10, 2001 at 16:48:55
Date: 3/7/01 3:18:12 PM Eastern Standard Time
Hi All,
TEXAS will QSY to 189.700 kHz this evening for Bill de Carle and others, running WOLF 24/7. Weather is clear and dry for a while, and antenna current is looking good. I will stay on 189.700 kHz for several days, and keep you posted.
Congratulations to both John Andrew in MA (1,534 miles) and Lyle in MN (~950 miles) on their reception of the TEXAS Beacon via WOLF on 187.040 kHz. (Stewart, once again, thanks for WOLF!)
Regards,
Bill Haslet,TX EM12hw, near Fort Worth
32N 55' 42"
97W 19' 80"
"TEXAS" & WD5CVG
VLF circuits
Posted by Martin Fuller on March 10, 2001 at 18:20:58
Are there any websites giving VLF receiver designs, either valve or semiconductor, or can anyone help with an attachment, Thanks
LF Engineering
Posted by Ko Versteeg NL9222 on March 11, 2001 at 05:14:06
Hi All
Does anyone have experience ordering things from LF Engineering? and the time it takes for Europe?
I did send an order for some 73Khz goods but they have not replied for more than 2 weeks.
Over a year ago they responded within 18 Hours..
The website is still there but that's about all,
Are they gone or what?
HELP!
73 de Ko, NL9222
Fwd: WOLF added to VE2IQ keyer
Posted by John Davis on March 11, 2001 at 10:16:23
(Bill de Carle announces:)
If anyone else out there wants to try WOLF and already has a BPSK-capable Tx which uses the "VE2IQ keyer" or some variation of it, here is an easy way:
I have added a "WOLF" mode to the MATIC program so you can upload a wolf-mode message directly to the keyer from your computer's parallel port. Alternatively, MATIC produces an Intel Hex file, so you could use that to program an Eprom.
MATIC is in the KEYER.ZIP file on my web page:
http://cafe.rapidus.net/bill1/bbs.htm
Bill VE2IQ
Loading Coil
Posted by Don Moler on March 11, 2001 at 11:04:19
These are links to pictures of my Loading Coil Form to be wound with 1/2 inch copper strap and placed on top of a 30' tower with a 40 foot diameter top hat for 1750 meter band.
The basic form takes shape.
Adding vertical support strips.
Finished and ready to wind.
Don Moler N8BKR
XM Wolfed in MA!
Posted by John Andrews, W1TAG on March 11, 2001 at 18:55:52
It took me a while to dig it out, but I found two successive lines of clean copy of Les Rayburn's XM in a recording made on 184.900 on Saturday, March 10, from 0800 - 0900Z. XM's frequency appears to be 1.2 Hz low, or 184.8988 kHz. This kept me from finding the ID until I expanded the BW a bit.
This 0300 local time hour has been very productive for me this winter. I am now in search of a crow to eat, having just complained to Lyle Kohler that I was never going to actually copy XM.
The distance to XM from here in Central MA is 1029 miles.
John Andrews, W1TAG
Variable Caps (air type)
Posted by Frank Carson on March 11, 2001 at 19:00:51
This is probably a simple question for most people, but, here goes. When you wire a variable capacitor (air type for tuning) which lugs do you hook up? I have one that has three on each side - which ones do I hook up to use the tuner? This is an example, I have several old tuners that I just got that I want to use in a loop antenna, but I have never messed with them before. Thanks for any help!
LOWFER / MEDFER List?
Posted by Steve McDonald on March 11, 2001 at 19:31:49
Can somebody direct me to an up-to-date list on the Web for the above...if there is such a place.
Tnx...Steve / VE7SL
Re: LOWFER / MEDFER List?
Posted by John Davis on March 11, 2001 at 20:42:54
The most up-to-date list there is can be found at this very site. From the site directory at the upper left of the lwca.org home page, click on the LowFER/MedFER link, then the "currently on the air" link.
John
Re: Variable Caps (air type)
Posted by Tim Brannon on March 11, 2001 at 22:32:03
Frank,
This sounds like a 3-ganged variable cap. Are the plates arranged into 3 groups? If so then there are probably 2 lugs connected to each set of stator (fixed) plates, one on each side of the capacitor frame. The rotor (movable) plates are all already connected together and common to the capacitor frame. You can confirm this with an ohm-meter. To connect all 3 sections of the capacitor in parallel to add them together, just wire all 3 lugs on one side together. Connect one end of your loop to this same wire (or any of the lugs now), and then the other end to the capacitor frame.
Net for Lowfers
Posted by Donald R Moler on March 12, 2001 at 09:24:01
Is there a net on the ham bands for lowfers ??? If not we should start one and meet maybe once a week. I would prefer 160 meters. If anyone is interested let me know. Don Moler Girard, Ohio N8BK Vonj@cboss.com
Re: Net for Lowfers
Posted by John Davis on March 12, 2001 at 09:41:41
There is indeed such a net, although on a rather loose schedule. They use to meet on 1983kHz, but nowadays may be found as low as 1961kHz.
73,
John
Re: LOWFER / MEDFER List?
Posted by Steve McDonald on March 12, 2001 at 13:52:16
Tnx John...geez I feel like a dummy!
Catalog entries have been fixed
Posted by Mick Reed on March 12, 2001 at 17:23:06
Well, the company apologized for the mistake, and now they have changed the description on their wepbage. The 40-some conductor wire is apparently real, although I haven't counted the strands yet. The company sent me the 40-some strand wire to replace the 'misrepresented' 53 strand stuff that I originally got. In this case, they didn't ask to get the original wire back, so I now also have 1000 feet of their 7 strand litz. I put it on my new 8' diagonal loop. Works good.
Re: VLF circuits
Posted by Clint Turner KA7OEI on March 12, 2001 at 17:29:11
There are few sites with schematics, etc.
Some of these include:
The "Radio Waves below 22 Khz" at:
http://www.vlf.it/
More specifically, at:
http://www.vlf.it/receptiontec1/receptiontec1.htm
There is also Eric Vogel's site:
http://home.flash.net/~evogel/
And Lyle Koehler has a some info on loop amp/design at:
http://www.computerpro.com/~lyle/
And Pierre Thomson has the "simple IC Preamp" at:
http://frodo.bruderhof.com/ka2qpg/longwave.htm
These are but a few to be found by some quick searching on the web.
Clint KA7OEI
Re: AND THE Medfer NC 510.500 KHz WINNER IS.........Mitch Powell, VE3OT!!!
Posted by George Jacob, GIR on March 12, 2001 at 18:06:36
Congratulations to you both for the fine work. I would be interested in knowing what type of antenna Mitch used in this. If you read it Mitch, email me!
George
Re: LOWFER / MEDFER List?
Posted by John Davis on March 12, 2001 at 19:46:25
We all feel that way at times, Steve. :-)
I hope the list is helpful.
John
Re: Loading Coil
Posted by Les Rayburn, N1LF on March 14, 2001 at 07:23:03
Impressive coil form! Can't wait to see the finished product. Don is obviously serious about pushing the edge of weak signal communications...a welcome addition to the group!
Homemade NDB receiver and matching active antenna
Posted by Aren van Waarde on March 14, 2001 at 09:12:25
Hi longwave lovers across the pond,
Last year I have been experimenting with a tuned loop (active antenna) and a homemade direct-conversion receiver for the reception of nondirectional beacons in the longwave band. If anyone is interested in my experiences: they are described at my own website:
http://members.tripod.lycos.nl/Aren/. Suggestions and responses are welcome !
Happy listening (and for some of you, happy transmitting),
Aren
Re: Homemade NDB receiver and matching active antenna
Posted by Donald R. Moler on March 14, 2001 at 11:41:02
I could not find your web site. Don vonj@cboss.com
Re: Homemade NDB receiver and matching active antenna
Posted by Mike Thompson on March 14, 2001 at 12:00:19
I got to his site fine, once I removed the period he had on the end of his address;)
Once you get there be patient cause it looks like its a slow loader.
Re: Homemade NDB receiver and matching active antenna
Posted by Mick Reed on March 14, 2001 at 13:13:35
The length of the html file at the address is 777. This is a joke.
EarthQuakes and Art?
Posted by Mike Thompson on March 14, 2001 at 14:53:29
Heres an interesting article for you ULF fans.
http://www.gaelwolf.com/pendulum.html
Re: Homemade NDB receiver and matching active antenna
Posted by John Davis on March 14, 2001 at 15:09:18
The site is legit. It's slow to respond sometimes, and you do need to make sure the period at the end doesn't end up in the URL box on your browser as observed by Mike T, below. (I've now modified the message to make it a live link that can be clicked. I can do that for any URL if the person who posts a message drops me a note and asks for it; otherwise, I only do it randomly.)
The only shortcoming I find on the site is that there are no schematics of the NDB receiver circuit.
73,
John
Testing New Feature
Posted by webmaster on March 16, 2001 at 00:40:36
0046 EST
Please excuse any temporary outages or error messages tonight. I am testing a feature which should make it possible for you to find out quickly when there has been an update to this message board without having to download the whole thing every time. I will advise you as soon as it is fully operational.
If any errors remain after tonight, however, please advise me at once. Thanks.
John
Re: Testing New Feature
Posted by webmaster on March 16, 2001 at 00:49:16
Needed a quick followup message to be sure the feature would work for replies as well as original posts.
Although I will formally announce the feature on St. Patrick's Day, I will actually leave it in service if it passes this test tonight. See if you can guess what it is!
John
Re: Homemade NDB receiver and matching active antenna
Posted by Charlie Vest on March 16, 2001 at 22:27:01
I didn't have any problem with the site but would have like to see a schematic rather than pics of the DC NDB rcvr.
Fwd: WOLF BPSK from UK
Posted by Jim Moritz on March 17, 2001 at 11:33:06
This message was forwarded by John Davis on 17 March:
Dear Lowfers,
I have recently set up my LF transmitter to run KK7KA's "Wolf" BPSK mode. I am hoping to start on-air tests this evening around 2000utc, on 137.500kHz, primarily so other European stations can try receiving tests with this mode. However I would also of course be interested in doing some tests with North American stations.
I can be QRV most evenings (from about 2000 till 0200utc or later). TX power is 1200W PEP, maximum ERP is about 1W. I can set frequency in 0.1Hz steps, with accuracy about 1 part in 10^7. The BPSK keyer uses the same reference oscillator.
The main thing to be decided for testing is the frequency. 137.4 - 137.6 kHz is the "digital" band segment here; also, if this is unsuitable, around 135.85 to 136.0, as used for the transatlantic QRSS tests is a possibility. Other frequencies in the band might be possible, but are certain to cause friction!
Any suggestions welcome.
Cheers, Jim Moritz
73 de M0BMU
Re: Fwd: WOLF BPSK from UK
Posted by Donald R. Moler on March 17, 2001 at 12:26:03
Jim, I would like to know what kind of antenna you are using and what is your location. I would like to know why you have so much antenna loss. I am new at this so please next time for us guys that are new to this group send more information .....Thanks. Don Moler Girard, Ohio N8BKR
Vonj@cboss.com
New MB Features
Posted by webmaster on March 17, 2001 at 14:26:48
I am delighted to report that two new features have been implemented on this message board.
(1.) In response to our recent survey, you said it would be better if messages opened in a separate browser window when you click to read a message on the list. Consider it done! All messages from March 1, 2001, will now open in a new window if your browser supports that capability. Nearly all recent versions do. (This feature actually worked on March 6, but the board administration software had to be rewritten for compatibility.)
We'll try to implement any other worthwhile suggestions you may have, too. Just drop me a note with your ideas.
John
Another User Survey!
Please indicate your choices in a followup to this message, and we'll proceed from there. Thanks! John
Re: Fwd: WOLF BPSK from UK
Don, Jim is not a regular to this list, but I'll try to answer some of your questions. The Buckmaster or QRZ online callbooks should show Jim's QTH. As for antenna efficiency, 0.1% is not that unusual for "normal" non-commercial-size radiators. Here in the U.S., legal Part 15 antenna systems are all well under 1% efficient and only a handful achieve over a few tenths of a percent. Probably the most efficient LowFER vertical on the air these days is Bill Cantrell's TEXAS beacon. With extraordinary measures to keep it in the clear, use lowest loss tuning components feasible, and make the grounding as effective as possible over high-conductivity soil, Bill calculates 5mW out for 1 watt into the system, or 0.5%. Bill Ashlock's loops may have an efficiency approaching that; however, it's hard to tell without actual field strength measurements to determine ERP. Any less efficient grounding, poorer soil, lower radiation resistance due to the longer wavelength at 136kHz, and the almost unavoidable presence of nearby vegetation and/or other structures in most locations --especially in the UK-- will be contributing factors in distinctly lower efficiency. 73,
Re: 60khz Antenna
there is a build your own antenna,which with modification tothe hp117a works just fine. it was in 73 amateur radio january, feb ruary and march 1994. covered building everything fromthe antenna to the comparator.
Re: Another User Survey!
I'd prefer the Times font...only for the small reason that you can't mistake a lower case "l" for a number "1". And a vote from here for the password protected live links. I don't like HTML code on mail lists, as it gums up simple text-based mail readers, but I'd assume that everyone using this site would have a browser. John Andrews
Re: Another User Survey!
Yes, I prefer the sans-serif fonts, such as Arial or Helvetica... I would prefer that we allow HTML posting and links in the current message board. It's easy to delete the few messages that would get posted that don't belong. Being security aware is fine, but not when it interfers with such a useful tool as this message board. The last thing we need is another source of info to have to check to stay current. Les
M0BMU Wolfed across the Pond!
In what will probably become a routine occurrence by next winter (at the rate we're going!), M0BMU was successfully copied in WOLF mode in Holden, Massachusetts between 0135 and 0200 UT on 19 Mar 2001. The frequency appeared to be about 0.13 Hz lower than the nominal 137.500 kHz being used. Two clean lines of copy were extracted after some adjustment of the command line parameters. With only the correct sound card sampling rate specified, the call sign could clearly be seen. By playing with the -s parameter, other parts of the message could be encouraged to come and go. At -s 1200, the two lines appeared. I did much more playing with that file during the day today, and have not produced any better results. The copy was made despite a loud local carrier at 137 kHz, which with my 500 Hz filter was bringing up the AGC (time for a sharper filter). I also believe that the message was decodable only after my neighbor shut off his light dimmer. In any case, conditions were hardly ideal, suggesting that someone with a REAL radio receiving site might do much better. Jim, M0BMU, is continuing his WOLF operation nightly this week, and is providing his schedule on the Lowfer and LF mailing lists. John Andrews, W1TAG
TEXAS WOLF received in North Carolina
Received about Ø1ØØ UT 2Ø MAR Ø1 C:\Dex\WOLF>wolf -q txa.wav -f 1849.6 -r 7941.81 WOLF version 0.51 t: 24 f:-0.710 a: 0.9 dp:119.4 ci: 1 cj:382 PD69D5A63TO5E*4 ? My first WOLF reception :) Dexter, W4DEX
Re: What's a good place to buy a TCXO?
Buying one is probably going to be fairly expensive but you can make one fairly simply. Build your oscilator circuit on a small piece of universal PC board and epoxy a NTC thermistor and a 20 ohm, 5w resistor (used as a heater) to the crystal can. connect the thermistor to a pot (set point adjustment). Connect the junction of the thermistor and pot to the + input of an op amp, connect a Vs/2 divider to the - input, use a NPN power transistor to increase the current capability of the op amp with the 20 ohm resistor from the collector to Vs. Operate with Vs = 10v. After making sure that it controls to a particular temperature, say 50 deg C, wrap the whole thing in several inches of fiberglass insulation. The temperature controller will take up a bit of room on the pc board. Note, the power transistor should not be on the pc board as its' heat dissipation will just confuse the circuit.
$6 Keyer for CW, QRSS and QRSS(S)!
Just received three of the new K1EL K-ID Chips the other day. These chips sell for $6.00 and can be assembled with a minimum number of parts. (Even I built one and it worked!) The chip comes pre-programmed with up to seven (7) CW messages which can then be selected and triggered. This unit was made specifically for beacon operation and then modified for the unique needs of "Lowfers". You can download a .PDF Adobe Acrobat file with schematics and complete details. At 6 bucks, these are hard to beat! You can convert your CW beacon into a QRSS(S) DX Machine for less than $15 bucks and 45 minutes of your time!
Re: Another User Survey!
Yes, the other typeface is better! Mick Reed reedmi@engr.orst.edu
Re: Another User Survey!
The sans serif has a slight edge for me; it appears a little larger although I think the font size is actually the same. HTML and live links would definitely be an advantage. You would know better than the rest of us, but I suspect the spamming would be minimal.
Hawai reception on Homebrew
It looks like my homebrew receiver is better than I thought. At 5:57 Pacific time, I heard LLD on 354.7KHz. I'm absolutely sure of the ID. Recently I've logged about 30 NDBs from around my location in Salem, OR. I use a multimeter to measure frequency, and I'm sure it's not calibrated. When I looked on AirNav, I couldn't believe it! 2547 miles. I'm using an 8 foot diag. loop with 14 turns center tapped, Lyle's balanced preamp, and a NE602 direct conversion receiver. Anyone know the wattage? 73 Mick
Is Tower Radiating Noise?
I have a severe power line noise (60 Hz) that is going to keep me off LF for good if I cannot figure out a solution...and it appears to be coming from my tower. Is this a common condition? When I loop the noise it seems to indicate the tower as the source. I have killed all power in the house and the shop so that there is nothing operating on the property and yet the tower still bangs away. Is there any cure for this condition and what would cause it? VE7SL / Steve
Re: Is Tower Radiating Noise?
Steve, I have had problems here with wideband noise modulated by 60 cycles or the other way around. In one case I found it to be coming from the telephone pole ground wire and once from an SCR motor control. I assume your talking about the same kind of noise. Pure 60 cycle current on your tower would not bother the signal on Low frequencys. In the march issue of QST I believe there is a circut for locating noise sources. Don Moler N8BKR Girard, Ohio Vonj@cboss.com
Re: Is Tower Radiating Noise?
Thanks Don...whatever the "noise" is (60 Hz hum mainly) definately destroys all ability to hear anything. The noise disappears when I move out of the yard...ie...road, neighbours...no noise...as soon as I approach the tower with the rx/loop, it goes off scale. This is with all power shut off on the property. Much worse at night...could the source be several blocks away for example and just working it's way into the tower via induction from the lines on the street (which seem quiet). Has anyone else experienced noise being re-radiated from their tower? Steve
Re: Another User Survey!
I too prefer the sans-serif fonts...and choose to use Arial for most of my computer editing, reading, etc. It seems to be easier on my eyes than most of the other fonts. Password protected posting forms get a thumbs up from me too. Not really a regular poster in here but appreciate the opportunity to add my $.02. Thank you.
Help using the WOLF software
Pasted below is what amounts to a typical overnight recording of BRO's beacon in Minnesota at a distance of about 976 miles from me. From looking, I do know that a repeatition in the "jm" heading means that there could be a signal there. How would I go about "narrowing in" on the desired signal using command line commands? If one of you WOLF guru's could post examples step by step to the group, it might help lots of us who are struggling. So far, I've only managed to snag TEXAS, and it just worked without tweaking. I think to add LEK, BRO, or NC to my list, I'll need to master the next steps. BTW, Stewart was kind enough to measure my soundcard sampling rate, Any and all help appreciated! Les Rayburn, N1LF C:\Wolf>wolf -f 788 -r 8002.3 -q bro3.wav WOLF version 0.52 t: 24 f: 0.541 a: 0.5 dp:114.1 ci:13 cj:297 KOGZR456MPB6JDI ?
Re: Is Tower Radiating Noise?
It seems that you are sure of the noise coming from the tower Therefore I would guess you are relativity close to the power lines and that the power lines are electrostaticly coupled to your tower. Inductance would not do it as the field is in the wrong direction and it falls off as the square of the distance. So my guess is your tower is capacity coupled to the power lines and the power lines are of a fairly high voltage and are modulated with industrial noise. You could make a E field antenna to check this out. ( an FET with it's gate tied to a vertical rod about four foot high ) If this is the problem you could reduce it with a faraday shield. Just put up a vertical pole between the lines and the tower and put a horizontal pole on top with some wires droping down to the ground. You could move your tower away from the lines. On most HV poles there is a ground wire running above the highvoltage line to prevent lightning damage, this line also reduces radiation from the power lines. If the lines in front of your house don't have a ground wire on top you may want to make friend with the power company and get them to put one up. You could also try insulating your tower from ground.
Re: Help using the WOLF software
Les, I believe a repeatition in the "jm" field indicating a possible signal only applies when the -l switch is used. Dex
Re: Help using the WOLF software
Les, Just at a first glance, the file doesn't look all that promising. As I recall, BRO was pretty close to being on frequency. Is the -f 788 offset the same as the one you used for TEXAS? If not, how did you determine that figure? Assuming that the -f 788 offset is appropriate, you might try throwing some 1/20 second delays in the command line, and look at the output. Start with -s 400, then try 800 and 1200. See what changes, and whether you have anything promising in the text. If everything just scrambles differently, then I doubt if there is a signal there. This is a good approach if you see some structure in the text, but it may be worth trying in any case. The -l option has not helped me much with weak signals. You could also try moving the -r parameter around a little. Sometimes a small change will show some patterns in the text. John
Re: Is Tower Radiating Noise?
I should have asked this question first .......Why not use a shielded loop for receive and the tower for transmitting. Don
Re: Is Tower Radiating Noise?
Hi Steve, At this point I certainly wouldn't rule out any of the thoughts you have received so far, but I'd like to expound a bit on one of them, then add another possibility. I presume the loop you're using is connected to a receiver working at LF, and the 60Hz related buzz is at RF. Let me also ask how tall your tower is. If it's of appreciable size, it could very well be picking up radiated noise from elsewhere in the neighborhood and providing relatively efficient coupling to the loop. If that's the case, though, it should also improve level of at least some desired signals too. A different thought, this time making the assumption that you turned off all power in the house with circuit breakers, but that at least some of your gear was still plugged in and was grounded by one or more paths to the tower. Do you suppose your tower ground is better than your electric meter ground and/or various pole grounds in the neighborhood, and an appreciable fraction of the power line noise in the vicinity is getting coupled to earth through your tower? That could cause it to radiate to a certain degree. 73,
Re: Help using the WOLF software
I have not had much success "helping" WOLF to do the decoding either. Yesterday I carefully measured the sound card sampling rate using John Andrews' Loran-C reference technique, and came up with a -r parameter of 8000.50. Using this value in combination with various -t and -f options did not let me extract either the M0BMU or NC messages from recordings. No surprise, because copying either signal at this location would be a long shot anyway. Next I recorded a 16-minute sample of TEXAS, starting at about 2:30 local time. With the default parameters, solid copy started at t:384. Using -r 8000.5 and -t 0.1, copy still started at t:384. The only thing that seemed to help was to use a large value (greater than 1 million) for the -s setting, so that the first several minutes of the file were thrown out. I'm assuming that there was some QSB and that TEXAS didn't peak until partway through the 16-minute recording session. It would appear that if you are within 1 Hz to start with, and the sound card sampling rate isn't off by more than 0.5 out of 8000, you are within the tolerances for WOLF decoding, and not much can be done (or needs to be done) to improve the copy. But I'm still learning, and trying to determine optimum settings is a *very* slow process.
Re: Help using the WOLF software
My experience in copying LEK on QRSS was that only during propagation peaks would LEK rise above my very high noise floor at this location...that alone may explain why I have not gotten copy on either LEK, My settings were the same used for the TEXAS reception. In any event, using the -t fuction and allowing for greater seperations like 2.0 or 2.5hz has not improved the copy. I will play with the -s parameter tonight has sugested by John Andrews and see if that improves the gibberish. One more question: Does narrowing the bandwidth that WOLF is searching in improve the ability to detect weak signals? For example,
Active Antenna Prototype of AMRAD tested
Through AMRAD's generosity, I've had the opportunity of trying out a prototype of their soon-to-be released E-field active antenna. http://www.amrad.org/projects/lf/JAN2001/JAN01.htm Full construction details are planned in an upcoming article in QST magazine.
Re: Help using the WOLF software
The -f parameter helps you home in visually on what's happening at the frequency of interest. It doesn't appear to modify the actual results when you are decoding something real. For example, if line 1248 contains some promising text at the end of the line, you'll probably see the exact same text if you narrow your window down with the -f parameter. Then again, you may see something promising on an earlier line that is no longer being yanked off to some oddball frequency. I do have the suspicion that LF skywave propagation has been down this week. Certainly the transatlantic stuff has all but disappeared at my place. Solar activity has picked up a little, and there have been high latitude auroras on two nights, anyway. All you can do is keep recording! Megabytes are cheap, I guess. John A.
Re: Help using the WOLF software
While I think of it, since we are running WOLF from DOS prompts, it might be useful to post some DOS shortcuts that you may have forgotten or never had the need to learn. Please chime in with additional suggestions. Pressing F3 will restate your last command line, but will not execute it until you push . If you keep the parameters that you are most likely to change at the end of the line, you can hit F3, backspace to the start of your change, and hit . This eliminates the need to constantly retype a long command line. There are two redirection commands that may be useful in saving WOLF outputs to a text file. The command wolf -f 799.765 -r 8001.96 > test would execute WOLF with the parameters listed, but instead of sending the results to the screen, they would be saved in a text file called "test". If you were to run this line again, it would erase and overwrite the "test" file. On the other hand, Other hints??? John Andrews
Still trying to figure out Xmit antenna
Hello All. Im still trying to get my beacon going. I would like to ask advice to anyone out there who may have a suggestion. I live outside of a small town in Idaho about 40 miles south of the CA border. There are two mountain ranges running north and south about 5 miles apart (the ranges strech for hundreds of miles). My house is located on the eastern base of the western range, at the very bottem. I have built my radio shack about 150 feet above the house on the side of the mountain, about 100 ft above the tree line (the vally tree line). Thanks in advance for any suggestions. Chris Curtis, N3DSC
Re: Still trying to figure out Xmit antenna
Chris, Put the antenna in a clear spot then get as much top hat as you can. For every picofarad of capacity you add to the top hat, you remove some winding on your coil and it is the I square R losses in the coil that eat up your power so removing coil turns is important. There are two places in your antenns that are going to eat up most of you power. One is in the radial system and the other is in the loading coil. So concentrate on these two when you are putting up your antenna and you will put out a signal that will be heard on the east coast. For a ground site you want an extremly poor ground conductivity as possable. Most antenna expermenters don't believe this but I have done more work on verticals than anyone I know and I have found out that verticals work best on very poor conductive ground systems or on very good conductive ground systems. It is the in between the two that make for poor verticals. The reason is this ... If the ground is a very poor conductor there will be no current flow, therefore how can there be I square R losses?.....If the ground is a very good conductor The I square R losses will be small....I once built a vertical on sand dunes to test my theory out and I was surprised that I only needed a few radials on sand but many on good conducting soil for the same results. Think of it this way ...Max transfer of power when the load matches the generator.. Make the load infinite and no power dissipation.....Make the load a dead short ....No power dissipation... All I am trying to tell you is that it may be better to put your antenna on the rocks.. what ever you do put in as many radials as you can... Make the loading coil with the idea that you want as much inductance as possable with a length of wire that is as short as possable. Make the diameter to length about one to one. ( go to page 32 in "Terman's book "electrical and electronic engenneering" There it will tell you about the optimum coil size for high Q . Always use a space between the turns. Never think small when winding a coil for 180 KHZ. Your coil diameter should never be less than two foot on this band. Place the loading coil at the top, Just under the top hat, Never, Never at the bottom of the antenna. I am now building and antenns with a loading coil that is wound with half inch copper strap with a diameter of three foot and about 3 foot long and it is going on top of my 30 foot tower. Don Moler Girard, Ohio N8BKR excuse the mistakes in spelling and grammer.
antenna
This is a reply to Tim's E-Mail. I would appreciate any response from anyone on this subject. Tim, I have been having some health problems and just woke up at 4 am. so I started to mess with my computer.(everything goes to hell when you get over 70 years old) and I saw your E-Mail.....I am going to write an article for QST if I ever stay healthy enough to finish this antenna. I have been fooling around with verticals for forty years and started an antenna company called "Moler Antenna Corp" about 20 years ago and advertised in 73 mag. I sold short verticals for 80 and 160 and 8ft dipoles for 40, 80 and 160. I came up with the invention of driving the coil at the top of the antenna and never patented it. At the time I was working full time as an field engineer and the antenna company was consuming to much time so I gave it up. I have more experience with short antennas than anyone in this group. When I am finished installing this antenna and write it up, those that are knowledgeable about antennas will copy this design for use on the low band. The only way to make an antenna super efficient is to place the coil at the top, ground the mast and drive the antenna at the loading coil. I invented this method back in 1974 but never patented it. I have pictures of and built some of these antennas for my friends and gave a demo at Dayton in 1980 but it never caught on...I built a short two element yagi on 160 meters and both elements were separately tuned and driven at the loading coil. and this had about 3 db of forward gain .My vertical antennas use a motor up at the loading coil to change the inductance to tune the antenna over the whole band and this is done by rotating a coil of a few turns inside the loading coil. My health has been slowing me down or else I would have had this 180 KHZ antenna finished by now. I expect to get the worlds record on 1750 meters with this antenna. I know I won't fail unless someone else builds this antenna first` If a record is going to be set it will be with this antenna design. I have thought this design out and the only improvement I can think of is to tilt the top hat ends up at about a 45 degree angle ...but then this may exceed part 15 rules ( my antenna will be 30 ft high with forty foot diameter top hat, a loading coil that is about 3 foot in diameter and 3 foot high. The loading coil is now being wound with one half inch wide copper strap and it will be driven at the top and the tower will be grounded.)
Re: antenna
There are some in the LowFER community who maintain that a loading coil at the top of the antenna will "choke off" the current going to the top hat, and won't work at all. At the other extreme there is Don, who claims that a loading coil at the top is clearly the most efficient system possible. Who is right? Comparisons of LowFER signals from different installations do not shed much light on the situation, because the ground system and the surroundings (trees, buildings, etc.) are often more important than the "antenna" itself. Fortunately, it is now possible for just about anyone with a computer to model a particular antenna design and predict how well it will perform. The accuracy of the prediction is not limited by the modeling software itself, but by the validity of the data you provide to the computer. Garbage in, garbage out still applies. However, with reasonable guesses for ground losses, coil Q and other system parameters, the modeling software will give reliable comparisons of antenna designs. QST recently ran an excellent series of articles on antenna modeling by L. B. Cebik. For a discussion of modeling that is specific to LowFER applications, visit my web site at http://www.computerpro.com/~lyle and view the article on "Computer Modeling of LowFER Antennas". There is free software available to do the modeling, and links are provided in my web article. So there is really no need to speculate about which loading system is superior, or just how efficient a particular antenna design really is. The answers are readily available. The subject of loading coil position on mobile whip antennas was studied to death many years ago. A definitive paper called "Optimum Inductive Loading of Short Whip Antennas" by R. C. Hansen was published in the IEEE Transactions on Vehicular Technology, May 1975. It shows a peak in efficiency when the loading coil is about midway up the whip. The peak is extremely broad, but efficieny drops off quite rapidly as the loading coil position is moved toward the top of the whip. However, these results are for straight whips without top hats. When most of the antenna capacitance is in the top hat, the actual loading coil position becomes less important, and it can be located almost anyplace between the base and the top hat without much change in efficiency. The antenna model examples in my web article allow you to move the loading coil in the various designs and see for yourself what happens. Remember, though, that these models are for antennas in an open field above a flat ground plane. There are some situations where a top loaded antenna is clearly superior, such as when it must be located near buildings and vegetation. Then it is important to avoid having the "hot" part (the part above the loading coil) near these lossy objects. Another situation where top loading is the *only* way to go is when a grounded tower is used, as in Don's proposed installation or in the antenna which has been used by LowFER BK (Bruce, W0BK) for several years. In Bruce's case, he wanted to combine the LowFER antenna with his HF installation for practical and esthetic reasons, and the top-loaded grounded tower provided a good solution. Modeling results showed that the efficiency of this type of antenna could be just as good as an antenna using a conventional insulated mast, *if* the capacitance between the top hat support and the tower could be minimized. After a few iterations, Bruce was able to get the capacitance down to a reasonable value, and BK puts out a very respectable LowFER signal. Better than his old base-loaded vertical? Maybe not quite, but the new antenna is considerably closer to some trees that are probably adding a lot of loss. If the antennas at TEXAS or LEK were replaced by grounded-tower designs in exactly the same locations, using the same ground systems, my own guess is that there would be little difference in radiated field strength -- maybe a 1 dB change one way or the other. Maybe when Don gets his new antenna on the air he will indeed blow us all away, and I'll be happy to embrace his design. For the time being, though, I consider a top-loaded, grounded vertical antenna system to be a good alternative if it happens to fit your particular needs. Not necessarily better or worse than other designs. As for loading coils themselves, it is easy to prove mathematically, or by trial and error using any of several coil design programs, that the minimum length of wire (which also results in maximum Q) for a given inductance in a single layer solenoid is achieved when the coil diameter is about 2.2 times the coil length. Optimum center to center spacing between turns is approximately twice the wire diameter (closer spacing is OK when Litz wire is used). In an HF mobile installation, a huge coil has a lot of stray capacitance to the "stinger" above the coil and the mast below the coil, and that has the effect of reducing the overall circuit Q. In this case, a length to diameter ratio of 1:1 is probably optimum. Similar considerations can apply when the loading coil in a LowFER antenna is very close to ground or to the top hat, so it may be better to use something less than a 2:1 diameter to length ratio in these situations. The AWG-COIL program on my web page will calculate approximate coil dimensions when you input the desired inductance and wire size.
Re: Wanted- Information AC & DC Powerline Carrier Communications
Frank, many radio amateurs expermented with carrier current communications during wartime when they were no longer able to transmit on the air. If you haven't already, take a look at wartime QSTs and ARRL handbooks, e.g. The Radio Amateur's Handbook, 1945 edition, Chapter XIX. 73 from London, Ontario. Harry, VE3GRO
Re: Still trying to figure out Xmit antenna
Thanks for all the responses. You have helped me a lot, even if it may be mainly motivational. Im now gathering up all the materials I'll need to setup my antenna. I plan to install some type of insulator on the roof of my radioshack (a 8' by 6' building). Install a guyed 40 ft vertical. Im going to attempt to use some of my open wire line to make a top hat as large as I can. I have a number of trees (thousands) to tie off from, that's a blessing an a curse. For now I'm going to put the coil 4' from the base, and plan to make it out of 1/8 inch solid copper wire used for grounding houses. I'll need to build it into a small garbage can for snow reasons. It can snow as much as 15 feet a year, I'm not sure I'm up to the engineering to get the coil at the top yet. I have a North Country AM88 xmitter to start with. I don't think this is considered to be a great exciter, but that's what I have. If anyone can hear me I'll try one of the computerized modes. My elevation is about 2200 feet an I have a great shot to the east. A few more questions. How do I ground this type of antenna for lightning protection. Does anyone have any feelings on a variable coil for the antenna, like the old coils that turned a smaller coil inside a larger one. Thanks again for the discussion. I hope you get your antenna up Don. I'll take some pictures and post them when I get going. Chris Curtis
160 meters still active
Hello all: Just received an ARGO capture of my 160 meter beacon from VE7SL in British Columbia. Steve sent nice jpeg of 1999.910 QRSS beacon as received last night ( March 24th). The 6AQ5 at 3 watts input must still be working - and I guess the season for QRSS just won't end. Steve is at approx 2100 miles.
MEDFERs "CT" and "VE3OT" logged on West Coast
I spent a few hours last night playing with the Argo QRSS software. I used some of the weaker NDBs to get the feel of how the program worked and to determine my rcvr offsets accurately. Started to listen for Clint's MEDFER beacon CT in West Jordan Utah and had a nice set of calls fairly fast. This was from his 100mw beacon in the 1700KHz band. Distance from here (Mayne Island, BC ..CN88) is 1270km or 791 miles. Feeling pumped, I next had a look for Mitch's (VE3OT) MEDFER beacon in Ontario in the 1900KHz band. Shortly after midnight I captured several nice sets of calls. Distance to Mitch is 3208km or 1993 miles...not bad for a 6AQ5! Argo is a great little program...very intuitive and straight forward. I would encourage anyone who is thinking of trying QRSS to start here. If you are running QRSS on MEDFER or LOWFER, I would love to give a listen next weekend, please let me know. And...thanks Clint and Mitch for having these great little signal sources pounding away to encourage us newbies! Steve / VE7SL
OF beacon on 510
Heard a morse code beacon sounded like OF on 510 khz... Any ideas who this is?? Thanks for any help it would be much appreciated. Shawn
Re: OF beacon on 510
OF is called Carsey in Norfolk, NE. It is 25 watts and on 510KHz. Check www.airnav.com under Navaids - it is a great online database.
WOLF experiment on 160m
K0LR will be running in WOLF BPSK mode as an experiment this evening, from about 2300 to 0500 UTC. The frequency is 1999.900 kHz +/- 1 Hz, at a power level of 1 watt. The identifier cycle is exactly 10 minutes long and begins with 6 repetitions of the WOLF message (9 minutes 36 seconds), followed by a 24-second CW identifier sequence at 12 WPM. I will synchronize the message timing manually so that each ID cycle will start at 0, 10, 20, etc. minutes past the hour. Details of the WOLF (Weak-signal Operation on Low Frequency) mode are given on the web site of Stewart Nelson, KK7KA at http://www.scgroup.com/ham/wolf.html The latest version of the WOLF decoding software can be downloaded from this site. Further information on using WOLF is available on Les Rayburn's site at http://www.highnoonfilm.com/xmgr/updates/wolf.htm Les also provides a summary of the WOLF operating commands at http://www.highnoonfilm.com/xmgr/updates/wolfop.htm A few basics of WOLF operation are given on my web site at http://www.computerpro.com/~lyle/wolf/wolf4dummies.htm 160 meters is probably not a good place for WOLF, because the propagation path stability, frequency accuracy and frequency stability of transmitters and receivers are all much poorer on 160m than they are at LF. This is just a fun experiment to see if it works at all.
Re: OF beacon on 510
thanks that is a new one for me.
Re: Still trying to figure out Xmit antenna
In 1987 Max Carter published a booklet called "Transmitting Antennas and Ground Systems for 1750 Meters", edited by Mike Mideke. It has a wealth of info, all experimental, since computerized antenna modeling programs weren't avialable then. On p. 44, Mr. Mideke reports results of tests, I believe in California, of 3 locations for his LF station. The first, in a valley, he represented as 0 dB with a range of 50 miles. The second, at 560 ft. elevation, was +12 dB and 220 miles and the third, at 1200 ft., was +20 dB and 2000 miles. He also mentions that, if you have a choice, put the antenna in the clear.
Re: WOLF experiment on 160m
K0LR was successfully copied here from 0120 - 0140Z on 27 March. Clean copy started at 192 seconds, and lasted for the rest of the file. Frequency was around 100 millihertz high, if I believe my setup. My receiving antenna was only a 40 meter dipole about 30 feet off the ground. John Andrews, W1TAG
Re: WOLF experiment on 160m
One 10 min. file made at 0340-0350, processed one time, seems almost to easy! This is the first time I have seen the frequency vary. Is this due to propagation of the 1999.9 signal? t: 192 f:-0.146 pm:4095 jm:425 K0LR/B EN36 1W - Dexter
Refunds for NDB BX Newsletter
Back sometime between 1988-1992 I tried to help Sheldon Remmington of Hawaii publish his "NDB DX Newsletter." He was having difficulty with the high humidity, postage stamps, and envelopes sticking together. I accepted pre-stamped envelopes from him, and I converted them at my local post office to cash (Post office charges 10% conversion fee). I then automated the address list, and stamped envelopes as they were needed to mail Sheldon's newsletter. Eventually Sheldon stopped publishing, and I was left with cash from stamps as well as pre-payment sent by interested persons. I owe refunds to many subscribers of Sheldon's "NDB DX Newsletter" If you think that this applies to you, please contact me at: kd4ace@compuserve.com or CHRIS CATOTTI PO BOX 621777 OVIEDO FL 32762-1777 U.S.A. Failure to send out refunds is entirely my fault, complicated by my moving, buying a house, birth of children, etc. As I was cleaning up boxes in the garage, I found most of my records. Best Wishes, Chris Catotti P.S. If appropriate, this letter may be published in th LWCA newsletter.
Re: Several questions from LW novice...
im beginning to have an interest in lowfer reception.
Fwd: solar alert
Date: 3/27/01 5:13:48 AM Eastern Standard Time From: Alan.Melia@btinternet.com (Alan Melia) The attached was received from NASA this morning, the sun has become very active suddenly within the last few days, so expect a prolonged period of disturbed conditions. AURORA WATCH: An interplanetary shock wave buffeted Earth's magnetosphere Tuesday morning and another may be following close behind. A coronal mass ejection that left the Sun on March 25th will arrive late Tuesday or Wednesday and possibly trigger additional geomagnetic disturbances. In recent days Alaskan sky watchers have enjoyed some of the best auroras of the current solar cycle Cheers de Alan G3NYK Alan.Melia@btinternet.com
LEK WOLF received in North Carolina
Received about Ø2ØØ UT on 28 MAR Ø1 C:\Dex\WOLF>wolf -q LEKd.wav -f 1849.61 -r 7941.81 WOLF version 0.52
WOLF + QRSS
Full Spectran screen: wolf-cw.jpg (92624 bytes) The upper trace is Lyle Kohler, K0LR, transmitting in WOLF mode. The lower trace is obviously Mitch Powell, VE3OT, in QRSS mode. I believe this was the first opportunity to catch the two modes on the same screen. John Andrews, W1TAG
FW: Even more solid at 11 pm !
Full-size Argo Screen: WAmar27th.jpg (101431 bytes) This came in last night from Mitch in London Ontario, (533 miles); see forwarded message below. The input power was down to 0.6w due to the wet snow and some contact of the critical lower leg with some branches (at least no positive "significant changes" as Mitch thinks). In an earlier message Mitch stated that he had some "buckshot" noise competition as can be seen in the capture but the WA is as sharp as it gets! Bill WA *****Forwarded Message***** Bill: 73 Mitch VE3OT **********
Xtal for 1990-1999?
Would anyone have an extra rock for this range? Would like to put up a QRSS bcn at the top end of 160...maybe can spur some activity out this way. Steve / VE7SL
A plug for LWCA heard on HCJB
I was listening on 9745 kHz to HCJB 29 March 2001 at 0155 UTC. They were doing a short feature on VLF, whistlers and the Northern Lights. They concluded the story by providing the LWCA name and address for more information about whistlers and VLF.
Re: A plug for LWCA heard on HCJB
That's great, Chris. Thanks for letting us know. John
1750 meter antenna
I am finally feeling better so I did some work on my loading coil. I had the coil form covered with fiberglass and cut the eight strips of plastic to hold the onehalf copper strap in place on the coil form. I had the hole for the 1750 meter antenna dug in a clear field in the back which is about 600 feet from the house and any power lines.
K0LR 160m beacon in QRSS mode
http://www.computerpro.com/~lyle
MedFER NC 510.500 beacon in QRSS mode
As requested MedFER beacon NC will be xmitting QRSS 3 sec dots until Monday. I will then run in whatever mode that is requested. Power, frequency and antenna tuning was checked today. 73,
Re: LW Antenna
How can I find out about what is availale on the long wave antenna market. Some sort of review and recommendations as to effectiveness would be most welcome. Can anyone help. To be used in conjunction with SONY's world transceiver. Many thanks for the reader's assistance.
www.lwca.org
potrzebie
Posted by webmaster on March 18, 2001 at 14:46:46
Last month we asked how you would like messages to open when you click on them, and we have implemented your preference. Now, here a couple more questions for you:
Posted by JohnDavis on March 18, 2001 at 16:00:15
John
Posted by bill bastian on March 18, 2001 at 17:05:25
i picked up a used hp-117a, put a voltage regulator at the 35 volt input to the preamp to swampit down to 12 volts, and a resistor, and hooked up the ferrite bar antenna built from the plans in the article. works just fine.
there is a commercial antenna available,which with a capacitor in the feedline, will work just fine with the hp-117a.
i can get you the details if you need them. expensive-several hundred dollars for it. building your own is under $50.
give me a snail mail and i can send you a copy of the article you can build it from. pc boards are available from FAR Circuits
also you can get me on telephone evenings/weekends at 608-372
7293.
Posted by John Andrews on March 18, 2001 at 18:55:26
Posted by Les Rayburn, N1LF on March 18, 2001 at 21:41:54
Posted by John Andrews, W1TAG on March 19, 2001 at 20:18:06
Posted by Dexter McIntyre, W4DEX on March 19, 2001 at 22:07:41
t: 48 f:-0.710 a: 0.8 dp:119.7 ci: 0 cj:320 2BGAHNKAFF7S ?
t: 96 f:-0.708 a: 0.6 dp:115.9 ci: 8 cj:126 86LX415S ZBCKL* -
t: 192 f: 0.029 pm:1429 jm:753 9FSAQJ*T2C09 VW ?
t: 288 f: 0.029 pm:3823 jm:753 TEXAS AGGIE 79 -
t: 384 f: 0.029 pm:5847 jm:753 TEXAS AGGIE 79 -
t: 480 f: 0.029 pm:7887 jm:753 TEXAS AGGIE 79 -
t: 576 f: 0.029 pm:10070 jm:753 TEXAS AGGIE 79 -
t: 672 f: 0.029 pm:10493 jm:753 TEXAS AGGIE 79 -
t: 768 f: 0.029 pm:10542 jm:753 TEXAS AGGIE 79 -
t: 864 f: 0.029 pm:10580 jm:753 TEXAS AGGIE 79 -
t: 960 f: 0.029 pm:10846 jm:753 TEXAS AGGIE 79 -
t:1056 f: 0.029 pm:10956 jm:753 TEXAS AGGIE 79 -
t:1152 f: 0.029 pm:10967 jm:753 TEXAS AGGIE 79 -
t:1248 f: 0.029 pm:11041 jm:753 TEXAS AGGIE 79 -
t:1344 f: 0.029 pm:11135 jm:753 TEXAS AGGIE 79 -
t:1440 f: 0.029 pm:11180 jm:753 TEXAS AGGIE 79 -
t:1536 f: 0.029 pm:11328 jm:753 TEXAS AGGIE 79 -
t:1632 f: 0.029 pm:11498 jm:746 4DHJWL/Y KTZ.0K -
Posted by Robert Bicking on March 20, 2001 at 20:50:11
Posted by Les Rayburn, N1LF on March 20, 2001 at 21:57:56
For Lowfer applications, you can selected from two fixed QRSS speeds. One is .2WPM (Dot length = 6 seconds) or .02 WPM (Dot length=1 Minute).
You can also use the same chip to send a sequence, such as XM in QRSS(S), followed by a complete ID, XMGR sent at regular CW speeds.
I suggest e-mailing them first with your specific needs and they can advise you on how to order.
Posted by Mick Reed on March 21, 2001 at 11:20:12
I would like to be able to directly put small pictures or links to them into the messages. I think the users would use this feature, 'we' are fairly advanced. (It would also save the webmaster time)
Posted by Tim Brannon on March 21, 2001 at 22:50:12
Posted by Mick Reed on March 21, 2001 at 23:10:06
Posted by Steve McDonald on March 22, 2001 at 01:35:11
Posted by Donald R. Moler on March 22, 2001 at 09:04:26
Posted by Steve McDonald on March 22, 2001 at 11:16:00
Posted by Jim Martin, WK1V on March 22, 2001 at 17:46:43
Posted by Les Rayburn, N1LF on March 22, 2001 at 20:18:59
I can't tell if there is likely a signal buried in here or not.
My background in BPSK tells me that if the gibberish repeats itself in several lines then you likely have a signal too.
so I know that's correct. The -f offset could drift a little, as it is only as stable as the Icom 746 with TCXO.
t: 48 f: 0.190 a: 1.4 dp:110.7 ci: 1 cj:406 LIZZG22O. MZGOT ?
t: 96 f: 0.536 a: 0.9 dp:109.4 ci:12 cj:145 7FRU8TK8AS1DQU7 ?
t: 192 f: 0.127 pm: 342 jm:742 OTV9 O9*GWHK/59 ?
t: 288 f: 0.264 pm: 380 jm:249 B6T35TB9E7P6L76 -
t: 384 f: 0.264 pm: 478 jm:249 SRQFVO9X5X08H*. -
t: 480 f:-0.166 pm: 577 jm: 20 IFGHBT UUU355XT ?
t: 576 f:-0.166 pm: 627 jm: 20 F6*D5.RC2GINOY0 -
t: 672 f:-0.098 pm: 722 jm:490 I5T0NKBTZJRV*U1 ?
t: 768 f:-0.098 pm: 747 jm:490 XBP*6D6 B/M18C3 ?
t: 864 f:-0.186 pm: 813 jm:188 GH4ML*MLL839XPA ?
t: 960 f:-0.186 pm: 890 jm:188 D2V3T0*UEKW9Z75 ?
t:1056 f:-0.186 pm: 895 jm:188 WAVD00WJ*ZH3EKE ?
t:1152 f:-0.186 pm: 938 jm:188 RX*QTXYM77TC.FB -
t:1248 f:-0.879 pm: 952 jm:743 H9XGRXIDMNS2S3N ?
t:1344 f:-0.449 pm:1136 jm:634 VR1TK/W9DENYYXW ?
t:1440 f:-0.449 pm:1154 jm:634 OY7GOM/2.NFHDBK -
Posted by Donald R. Moler on March 22, 2001 at 21:02:18
Don Moler Girard, Ohio N8BKR
Posted by Dexter McIntyre, W4DEX on March 22, 2001 at 21:07:57
If you process with the -l switch and get multiple hits of the same values in both the "jm" and "f" fields there probable is a valid signal there.
Posted by John Andrews on March 22, 2001 at 21:50:01
Posted by Donald R Moler on March 22, 2001 at 21:50:45
Posted by John Davis on March 22, 2001 at 22:55:08
John
Posted by Lyle Koehler on March 23, 2001 at 10:48:04
Posted by Les Rayburn, N1LF on March 23, 2001 at 11:26:44
BRO, or NC at this point.
The sound card was measured at -r 8002.3 The -f setting is believed to be accurate (this setting worked for TEXAS and I doubt that the TCXO in the Icom 746 drifts much)
if I set the -f parameter to .5 does that improve the softwares ability to detect weak signals?
Posted by Steve Ratzlaff on March 23, 2001 at 14:19:07
I tested the antenna on the bench at work for intercept points and frequency response, using signal generators and a spectrum analyzer and network analyzer, and also tested it outdoors at my very-urban, RF-noisy home in East Palo Alto, CA (part of Silicon Valley, with 24 AMBC stations giving S9+20dB or greater reception!) The antenna gave a very good account of itself.
The circuit is based on Ralph Burhan's E-field antenna using jfets/VMOS fets and noiseless feedback, updated with a modern power jfet from Crystalonics, the CP series (CP650/CP666). This poer jfet was first tried in Burhan's circuit by noted experimenter Dallas Lankford; Dallas shared the information with AMRAD who developed the basic circuit into a complete outdoors active antenna. Frank Gentges, K0BRA, is the LF "brains" behind AMRAD's active antenna project.
I've been using various E-field active antennas as my primary LF receiving antenna since the 1980's; originally I used Burhan's semi-kits (no longer available), then later made my own clones, and other circuits adapted from designs from work. I can state that AMRAD's prototype antenna worked very well, especially in my noisy urban location. During a lull in my local S5 lightdimmer-type noise buzz, I was able to copy all 3 Russian ALPHA stations (11-15kHz), and happened to catch 20.5kHz 3SB, Datong, with a lengthy CW message, inaddition to the the normal LF NDB reception.
This antenna should be able to be built for under $75. Watch for the upcoming QST article giving full details of its construction.
Steve Ratzlaff
Posted by John Andrews on March 23, 2001 at 16:18:35
Posted by John Andrews on March 23, 2001 at 21:07:08
wolf -f 799.765 -r 8001.96 >> test will save the output in the "test" file, but will append it to any existing text in that file. Note that in either case, the WOLF output will not appear on the screen. You'll have to look at the file with a text editor to see it.
Posted by Chris Curtis on March 24, 2001 at 11:38:30
My question, where to put my lofer antenna? Do I put it down near my house, on flat land, over my garage roof. I could get a 35ft vert with a top hat installed there but it is right in the trees. Or do I put it up at the redio shack where I have some hight but the ground is all rock, and the side of the mountain sits so close by. Or do I say forget the FCC (a tool of corporate thugs) and install some type of long wire Xmit antenna, then I would have miles of space to play with. My only want is that SOMEONE may hear me occasionally so that all my time is not waisted.
BTW, I have a 80 meter open line dipole at the shack up 65 feet, I thought about shorting the open wire at the shack for a top loaded vert. What do you think?
Posted by Donald R Moler on March 24, 2001 at 21:07:33
Posted by Donald R. Moler on March 25, 2001 at 05:28:41
I had about 2000 feet of this copper strap slit for me back in 1978 and have lots on hand. I seen pictures of LEK's antenna and it can be improved in many ways. He has not yet optimized his antenna to where it will be most efficient. Jim Frank, KT8D and myself tested these short antennas on 80 and 160 meters back in the 70's and what we found out was that a short vertical antenna will out perform a full size quarter wave if it is built right, and the reason is the full size will couple into trees and has a e-field that spreads out far and can't be controlled, where as a short antenna with a large top hat has more of a local e-field. I won't go into detail here but the proof will be in the testing of this antenna. Don Moler Girard Ohio N8BKR vonj@cboss.com ----- Original Message ----- From: "Tim Brannon" To: Sent: Saturday, March 24, 2001 7:15 PM Subject: Top vs base loading a LowFER vertical
> "Place the loading coil at the top, Just under the top hat, Never, Never at
> the bottom of the antenna."
> > Don,
> I want to point out that TEXAS, LEK, and OK all use base-loading on their
> LowFER verticals. These are pretty much the most successful LowFER stations
> of recent years if you look at DX reports. A few years ago Bill Bowers (OK)
> reported on some experments with top-loading and found no improvement in his
> far-field signal, although he was using ferrite-loaded coils at the top.
> > I've read before that top-loading *should* produce a more favorable current
> distribution for the radiator, and that this is a well established
> philosophy at the lower HF bands and 160m. When you get your top-loading
> inductor installed I think you should report your findings in the LOWDOWN.
> > 73,
> Tim Brannon
> KF5CQ
>
Posted by Lyle Koehler on March 25, 2001 at 12:07:39
Posted by Harry MacLean, VE3GRO on March 25, 2001 at 12:54:40
Posted by Chris Curtis on March 25, 2001 at 14:08:12
Posted by Mitch VE3OT on March 25, 2001 at 18:25:36
Just a reminder that the 1999.910 will be on indefinitely from London (ON) for practice, etc of QRSS/ software practice.
73 Mitch VE
Posted by Steve McDonald on March 25, 2001 at 19:13:20
Posted by Shawn Axelrod on March 25, 2001 at 19:28:54
Posted by Mick Reed on March 25, 2001 at 22:32:40
Posted by Lyle Koehler on March 26, 2001 at 17:51:52
Posted by shawn axelrod on March 26, 2001 at 21:27:51
Posted by Robert Bicking, W9RB on March 26, 2001 at 21:40:22
Posted by John Andrews on March 26, 2001 at 21:53:08
Posted by Dexter McIntyre, W4DEX on March 27, 2001 at 10:46:17
t: 288 f:-0.146 pm:6718 jm:425 K0LR/B EN36 1W -
t: 384 f:-0.195 pm:7362 jm:424 K0LR/B EN36 1W -
t: 480 f:-0.166 pm:9460 jm:424 K0LR/B EN36 1W -
t: 576 f:-0.049 pm:12172 jm:424 K0LR/B EN36 1W -
t: 672 f:-0.049 pm:12179 jm:424 K0LR/B EN36 1W -
Posted by Chris Catotti on March 27, 2001 at 16:40:32
Posted by George Hardesty on March 27, 2001 at 20:46:38
has anyone been able to use an ft847 to recieve with.. thanks any and all comments welcome .. George/ka9ycb
grid em57qq
Posted by webmaster on March 27, 2001 at 22:25:27
Sender: majordom@post.thorcom.com
------------------------------
SOLAR ACTIVITY: In recent days the Boulder sunspot number has rocketed to 339, its highest level since July 2000. At least one large sunspot group has a complex magnetic field that could harbor energy for powerful solar flares. Forecasters estimate a 20% chance of an X-class eruption during the next 24 hours.
----------------------
Posted by Dexter McIntyre, W4DEX on March 28, 2001 at 00:06:29
********************************************
t:1248 f: 0.010 pm:3392 jm:347 LEMRJE5SN*JKI9C ?
t:1344 f: 0.010 pm:3825 jm:347 LEK AITKIN MN -
t:1440 f: 0.010 pm:4467 jm:347 LEK AITKIN MN -
t:1536 f: 0.010 pm:4933 jm:347 LEK AITKIN MN -
Posted by John Andrews on March 28, 2001 at 09:24:41
Posted by William Ashlock on March 28, 2001 at 16:10:02
From: Mitch Powell [mailto:PowellM@claven.fanshawec.on.ca] Sent: Tuesday, March 27, 2001 6:00 PM To: William.Ashlock@edwards.boc.com Subject: Even more solid at 11 pm !
I couldn't help sending you this QRSS picture, taken just before 11 pm (Tuesday evening) As we speak (?) the signal is building - could have a QSO at this rate. You must have made some significant changes.
Posted by Steve McDonald on March 28, 2001 at 22:21:33
Posted by Chris Catotti on March 29, 2001 at 15:23:54
Posted by webmaster on March 29, 2001 at 16:35:52
Posted by Donald R Moler on March 30, 2001 at 22:38:30
The tower will be thirty feet high and on top will be my three foot diameter loading coil with a forty foot diameter top hat on top. I expect to wind the loading coil tomorrow and test the Q of the coil alone at different heights above the ground to see at which distance the Q is effected by the ground. Then I will place the top hat disk support and the tower near the coil to see if there is any eddy current losses. If so I may have to slot the disk to eliminate the eddy currents. Years ago I sloted my Hustler mobile antenna and filled the gap with epoxy and by doing this I was able to take a few turns off the coil as these eddy currents reduce the inductance of the loading coil and make the coil more lossy. I am hoping I can get this forty foot top hat and three foot loading coil on top of the thirty foot tower with out distroying it. I have been taking pictures of this antenna as I contruct it and will post the pictures on this web site so if any one wants to build another like it it will be much easier. I have a 35 watt solar panel that will power the whole system plus supply power to a heater to keep the loading coil from getting dew formation. I will post a notice on here when I first fire this monster up. Don Moler Girard, Ohio N8BKR vonj@cboss.com
Posted by Lyle Koehler on March 30, 2001 at 23:08:03
For the next two evenings (Friday and Saturday), K0LR will be operating with a power of 1 watt in QRSS mode (3 second dots). The frequency is still 1999.900 kHz. I don't think WOLF has much of a chance on MF with the present geomagnetic conditions.
-- Lyle, K0LR
Posted by Dexter McIntyre on March 30, 2001 at 23:10:26
Dexter
Posted by Nick Maync on March 31, 2001 at 21:35:34