Re: WD2XDW S-9 in Warwick, OK
Hal,
You could run SSB on 1750 meters (160-190kc) if you can get that on your Part 5 license. I have both the 2200 meter & the 1750 meter bands on my license.
Mike
LF T-P DX Test / VA7LF
Posted by Steve McDonald on October 03, 2005 at 20:39:04.
We will be conducting two-way tests with ZM2E for the next three nights on the 2200m band. Any and all reports would be very welcome.
Both stations will be using DFCW transmissions with .4Hz shift between dot and dash elements, QRSS 120 to start.
Frequency: 137.789 / 137.7886
ZM2E will transmit first, starting at 0626Z.The tests will end at sunrise in British Columbia at 1417Z.
If you are able to watch using Argo or Spectran set to QRSS 60 or 120 your screen captures would be greatfully received.
VA7LF / South Pender Island, B.C. (CN88)
Steve / VE7SL help wanted - for hire
Martin / VE7MM / G4EZG
Scott / VE7TIL
Posted by herb fisher on October 05, 2005 at 09:24:17.
I need someone who can help me pursue solutions to theoretical and mathemathematical problems for transmitting and receiving signals, magnetically, between 20KHz and 40KHz range. Specifically, I need to understand how to pick the best
carrier frequency in the above range
sensitivity improvement due to picking the right number of turns, loop diameter, coil Q, for the purpose of getting the best SNR.
I know there are many tradeoffs, but I don't see how to handle them.
I would be willing to pay for this service!!! It will be worth it, to me.
so if you have some familiarity with the maths, and theories, please send me your phone number and I will call back you on my nickel.
mailto:herb.fisher@takata.com Re: Best consumer radio for Longwave?
248.848.2729 desk
Posted by yaffle on October 05, 2005 at 21:49:56.
In Reply to Best consumer radio for Longwave? posted by yaffle on September 29, 2005 at 09:09:05.
Ok, for those who might be interested, sangean makes a version of the CC radio+ (which they make for C.Crane) which has longwave
http://www.sangean.com.tw/SHO/Product_PRD3L.asp
That's probably what I'm going to get.
WD2XFE Reception Report
Posted by Robert Bicking on October 07, 2005 at 23:27:03.
I received the first (other than local) report from VE3EAR who is located on the eastern shore of Lake Huron in Canada. The Part 5 beacon is sending XFE @ QRSS30 with a WD2XFE ID @ 9 wpm every 19 minutes on 137.73 kHz. Am looking for more reports while continuing to experiment with tuning to increase antenna current. The 31' vertical antenna is less than 2% of the usual (for ham bands) quarter wave vertical but it does have a 24' top hat which helps a bit.
Re: WD2XFE Reception Report
Posted by Alan G3NYK on October 09, 2005 at 20:00:17.
In Reply to WD2XFE Reception Report posted by Robert Bicking (W9RB) on October 07, 2005 at 23:27:03.
Hi Robert, what power are you running and what antenna current can you see?? Can you get more top load out? That will be vital to incresing the ERP from an antenna of that size. My Marconi has a 35 foot vertical but 450 feet of top wire loading. This gives a total capacitance of about 800 to 900pF and a ground loss of about 40 ohms. On my sandy soil your antenna would, show a groundloss of about 250 ohm.
that would be about 700mA antenna current when excited by 100 watts
Cheers de Alan G3NYK
Coney Island Radiobeacon
Posted by Michael St. Angelo on October 09, 2005 at 22:14:59.
Towards the end of the 1979 cult movie "The Warriors" there is a picture of a VLF beacon antenna and doghouse in Coney Island, NY. It seems to be in a dune close to the beach. A picture of the antenna is shown in the followinf still:
http://warriorsmovie.co.uk/filmstills/images/still12.jpg
Can anyone identify this beacon?
Thanks,
Mike N2MS
FWD: Trans-Pacific Canadian Amateur LF Signals Confirmed Heard
Posted by John Davis on October 09, 2005 at 23:20:06.
From: Steve McDonald jsm@gulfislands.com
To: lowfer@lwca
Subject: [LW] Trans-Pacific Canadian Amateur LF Signals Confirmed Heard
Date: Oct 9, 2005 10:57 PM
** Trans-Pacific Canadian Amateur LF Signals Confirmed Heard **
The first confirmed trans-Pacific reception of Canadian amateur LF (2200m)
signals occured on the morning of October 4, 2005. The slow speed (QRSS) CW
signals of VA7LF were confirmed heard near Wellington, New Zealand, at the
Wellington Amateur Radio Club station at Quartz Hill. Signals from the ZM2E
club station were heard in Canada as well but propagtion was not of
sufficient duration to enable a QSO to be completed. VA7LF was located on
South Pender Island, British Columbia and operated by VE7TIL, VE7SL and
VE7MM. The Quartz Hill station was manned by ZL2CA and ZL4OL. The present
amateur radio LF world record two-way is shared by ZM2E and UA0LE, a
distance of 10,311 km. The distance between VA7LF and ZM2E is approximately
11,700 km. Both stations were operated on 137 kHz using DFCW QRSS120.
VA7LF was running approximately 1 watt erp while ZM2E was at the 5W erp
level.
Propagation conditions were generally poor during the three night test
period.
The next scheduled trans-Pacific tests will be in the spring of 2006.
As Bob Vernall, ZL2CA, summarized, "The bottle of bubbly
is back in the cellar ...."
Kenneth Budden Obituary
Theoretical physicist Kenneth Budden passed away in September. For details of his career, see http://www.timesonline.co.uk/article/0,,60-1819719_2,00.html -Mike Terry
Hifer LP OFF THE AIR
Posted by Larry Putman on October 11, 2005 at 19:29:06.
Hifer LP is now SK "OFF THE AIR"
My thanks goes to all those that sent reports for the last 2 years!
I really did appreciate it!
73
Larry WB3ANQ
Re: FWD: Trans-Pacific Canadian Amateur LF Signals Confirmed Heard
Posted by Mike Terry on October 12, 2005 at 10:35:08.
In Reply to FWD: Trans-Pacific Canadian Amateur LF Signals Confirmed Heard posted by John Davis on October 09, 2005 at 23:20:06.
A news release describing the receptions appears on the ARRL Web Site: http://www.arrl.org/
Mike Terry
first TA LW BC of the fall season tonight
Posted by Scott Michigan on October 16, 2005 at 00:15:48.
First TA LW BC of the fall season tonight: 0400Z R. France 162 Kc (weak to moderate), then at 0405Z Europe 1 183 Kc (moderate).
Hifer RY Off for Season
Posted by John Andrews on October 16, 2005 at 18:48:21.
Hifer beacon "RY" in Raymond, ME is off for the season, but will return in May.
John Andrews, W1TAG
(Fwd) AFRICAM Ver 5.1
Posted by John Davis on October 17, 2005 at 11:26:47.
(From Bill de Carle, via the LWCA LowFER reflector:)
Having noticed AFRICAM is vulnerable to sound card sampling rate errors, I added the ability to specify the exact (nearest integer) sampling rate. AFRICAM defines its bit times by counting samples, so if the actual rate was too far off nominal, the program could not sync or hold sync
I am always amazed by how far off the actual sampling rate is for some (most?) sound cards. For example, I just recorded an audio file under Windows XP using Cool Edit, asking for 8000 samples per second. I input an 800.0 Hz sinewave synthesized from a crystal source, then measured the frequency of the
800-Hz tone in the recording. The actual sampling rate turned out to be 8100
s/s!
AFRICAM defaults to the following nominal rates:
SB16 or compatible : 8000 s/sIf you can measure the *true* sampling rate of your sound source and type it in, it will help considerably in establishing and maintaining proper sync.
ESS688 chip based : 8200 s/s
Sigma-Delta board : 7200 s/s
One way to get AFRICAM to run under Win-XP is to record an audio file off the air, like the original WOLF. The desired format is 8 bit unsigned (single precision) or 16-bit signed (double precision) MONO values of raw data sampled at say 8000 s/s. Cool Edit can do this: select the raw data (.pcm) mode, and be sure the saved file name has an extension of .AUD. Then when you invoke AFRICAM, use the "DISK" command line parameter - which tells AFRICAM to take its audio from disk instead of trying to talk directly to a sound card or sigma-delta board connected to a serial port. That makes Win XP happy. You still get to type in the exact sampling rate at which the audio was recorded (it won't be 8000 unless you get real lucky).
In a pinch, you can record a 16-bit MONO .WAV file at 8000 s/s and just change the file extension from .WAV to .AUD before passing it to AFRICAM. That way the first 40 or so words of the file (.WAV header) will be treated as audio samples when they are not, but it doesn't matter too much.
Version 5.1 of AFRICAM is available from my web site:
http://www.magma.ca/~ve2iq
Good luck!
Bill VE2IQ
coil give away
Posted by John Maguire on October 22, 2005 at 01:17:46.
I am disassembling a 160 Khz station in Essex CA. Expediency usually dictates junking some valuable components in the antenna tuner. There are two coils about 30 to 36 inches in diameter that were resonant at 160 Khz. There are two silver plated roller inductors two fixed value vacuum caps and a vacuum variable. I'd love to give them for free to some one who could use them rather than bust them up and junk them. It would require a pick up truck to move them. low power 11 meter beacon
If interested, drop me a note.
John Maguire
w1cdo@arrl.net
Posted by Matt on October 28, 2005 at 22:42:48.
hey all I have a low power (about 50mw) 11 meter beacon I can put on ******************************* I'm pretty sure it falls under part 15 rules for homebuilt devices.
Matt
Re: low power 11 meter beacon
Posted by Webmaster on October 28, 2005 at 22:44:09.
In Reply to low power 11 meter beacon posted by Matt on October 28, 2005 at 22:42:48.
Sorry, Matt. There are no alternate Part 15 provisions for homebuilt 27 MHz devices any more.
The only Part 15 rules for 11 meter operation at the present time are field strength based, and are so low as to preclude anything but extremely local activity.
We therefore do not list beacons in that band. Help - Finally got a SLM - Having trouble using it...
Posted by Al on October 28, 2005 at 22:48:31.
Hi Folks,
I finally bought a Selective Level Meter to help with NDB DXing - But I'm not sure how it should be set up for this purpose. I thought it was going to be straight forward. I have a photo copy of the user manual, but it hasn't helped me much so far. It is a Cushman CE-24A. Does anyone else here have one who can tell me how it should be set up?? I've been experimenting with antenna connections, but I haven't even been able to pick up any local beacons.
I'm not sure if something is wrong with this unit (got it from e-bay).
Any help would be greatly appreciated!
Thanks,
Al Re: Help - Finally got a SLM - Having trouble using it...
Posted by Tom Kennedy on October 28, 2005 at 22:51:03.
In Reply to Help - Finally got a SLM - Having trouble using it... posted by Al on October 28, 2005 at 22:48:31.
Al,
I cant say i am very familiar with this model, however i have owned several Selective Level Meters. I wonder if you have been able to recieve any AM Broadcast stations? I notice the spec is -80 dBm sensitivity. This may not get you any but the strongest of the beacons in your area. Also, what are you using for an antenna?
Tom Re: Help - Finally got a SLM - Having trouble using it...
Posted by Alan G3NYK on October 28, 2005 at 22:53:30.
In Reply to Re: Help - Finally got a SLM - Having trouble using it... posted by Tom Kennedy on October 28, 2005 at 22:51:03.
Hi Al, I have a couple of Wandel and Goltermann SLMs. These are used for LF listening but they do have -120dBm sensitivity (this is about .2uV in 50 ohm) My guess is that with only -80 (100 times less sensitive) you will need substantial pre-amplification in front of the SLM (2 stages ?)
Another thing to remember is that these were designed for line measurements not radio. They are a "receiver" but the front end is wideband...no preselection, so they are prone to intermod from strong local stations. I suggest a preamp with lowpass filtering to cutout signals from the MW BC band from reaching the amps or the SLM front end, but pass the NDB band.... probably 600kHz lowpass??
Put a wire antenna into the highest impedance input for best sensitivity (assuming that it is not resonated) and look for a local MW BC station, you probably wont hear much weaker than that until you have a pre-amp.
Best of Luck
Alan G3NYK
Re: Help - Finally got a SLM - Having trouble using it...
Posted by Al on October 28, 2005 at 23:00:30.
In Reply to Re: Help - Finally got a SLM - Having trouble using it... posted by Alan G3NYK on October 28, 2005 at 22:53:30.
Re: Help - Finally got a SLM - Having trouble using it...
Webmaster Note - Due to a glitch when performing maintenance this week, I am having to re-create this thread from scratch. Unfortunately, the error caused Al's response to be overwritten by a different post, so we do not have it available. I regret the inconvenience. (Al, if you remember what you wrote in response to Alan's first message, you can e-mail it to webmaster@lwca.org and I'll post it here in the proper sequence.) -JHD
Posted by Alan G3NYK on October 28, 2005 at 23:03:52.
In Reply to Re: Help - Finally got a SLM - Having trouble using it... posted by Al on October 28, 2005 at 23:00:30.
Hi Al, dont rush too fast for that other expensive filter. There is not usually that much difference between them and the specs can be confusing. Filters only have good performance when they are correctly matched and this is quite difficult in front of a receiver at LF. The receiver end may be OK but LF antennas are all sorts of strange impedances.....and if you use a wideband antenna then the impedance will vary wildly. The contrary to this is if you are using an amplifed whip or loop which has a coax matched feed at 50 ohms. Check to see whether you have a problem with higher frequency signals first. Try to identify the culprit. The difference in stop-band will probably only be 10dB at best. The other solution is to use the old trick of sticking a rejector circuit in for the one (probably) that is most local and giving the most problem. If you can measure a signal (S-meter) and put an attenuator in front of the reciever, this is the easiest way of detecting an intermod condition. If you apply say 10 dB in front of the receiver and the "annoying" signal drops much more than this (20 or even 30dB)it is an IM product being formed in the receiver. If it drops by 10dB it is a "real" on frequency signal
Good Luck and enjoy your beacon hunting. Next project is to look up the K9AY antenna !!
Cheers de Alan G3NYK
Testing Varactors on K0LR Balanced loop preamp
Posted by chris waldrup on October 28, 2005 at 23:09:47.
In addition to my LF experiments here at home I am a volunteer at the Pisgah Astronomical Research Institute, an astronomical radio observatory in the mountains of NC.
They have a receiver for VLF/LF and use Lyle's balanced loop preamp. I was told that their setup quit working and lightning was suspected. How can I test the MVAM109/NTE618 varactors to make sure that they are ok during my troubleshooting? I didn't know if ohmmeter tests would work with varactors. I was going to build a test jig with a pot, series resistor and blocking cap if resistance checks wouldn't work.
Unfortunately I only have the preamp with me. The antenna and receiver are at the observatory which is 250 miles west of here so I have no way to do a final test.
(The other part of my alternate test setup would be the jig described and my AADE LC meter.)
Any thoughts would be greatly appreciated. Thanks!!
Chris
KD4PBJ
Apex, NC
Re: Testing Varactors on K0LR Balanced loop preamp
Posted by Tom Kennedy on October 28, 2005 at 23:17:51.
In Reply to Testing Varactors on K0LR Balanced loop preamp posted by chris waldrup on October 28, 2005 at 23:09:47.
Chris,
Unless you are able to make your portable LC meter work properly as part of a reverse biased DC test circuit (440 pF @ 1.2V, 22 pF @ 8 V) field testing WILL be difficult.
In general it has been my experience that if they pass the simple DC ohmeter test they are probably OK. Good luck.
Tom Some Historic Wooden Towers
Posted by Obelixx on October 28, 2005 at 23:22:10.
· The aerial test facility Brück is a facility for antenna measurements established in 1939 by Telefunken. The buildings of aerial test facility Brück served from 1945 to 1957 as dwelling for war refugees (still today some building foundations and shelter remainders are present on the area). In 1956 the German Post began to build a facility for antenna measurements. Because metallic parts would disturb the directional radiation patterns, the towers had to be built of wood, without any metallic parts.
One of the three towers burned down on April 20th, 1979 and was not rebuilt, so there are only two wood towers, both of which were built in 1963.
http://en.structurae.de/structures/data/index.cfm?id=s0010788
http://skyscraperpage.com/diagrams/?b41640
http://en.structurae.de/structures/data/index.cfm?ID=s0010787
http://skyscraperpage.com/diagrams/?b41641
· The Radio Tower Ismaning, nicknamed the "Bavarian Eiffel Tower," was a 163 metre tall radio tower built of wood at Ismaning, Germany. In 1932, two shorter towers supported a T-antenna for mediumwave broadcasting. Two years later, one was dismantled and moved to Nuernberg, where it stood until 1969. The second tower was elevated onto a 39 metre substructure. The MW broadcast was discontinued in 1966. The tower was used for FM broadcasts from 1966 until 1977. It was demolished in 1983.
http://en.structurae.de/structures/data/index.cfm?ID=s0010728
· Gliwice Radio Tower is, since the demolition of the radio tower Ismaning, the tallest tower built of wood in the world. Gliwice Radio Tower itself is nicknamed "Silesian Eiffeltower."
Technical data: http://en.structurae.de/structures/data/index.cfm?ID=s0012024
Height: 118 metres
Area at the base: 20 metres
Pictures:
http://upload.wikimedia.org/wikipedia/de/0/0c/Sender_gliwice.jpg
http://www.muzeum.gliwice.pl/image/wystawa-radiostacja_kaminski.jpg
and more in the gallery at http://www.dxradio-ffm.de
Transmission on the medium wave frequency 1231 kHz with a power of 5 kilowatt started on December 23rd, 1935. On August 31st, 1939, a raid of the station was faked by the SS, but for propaganda purposes was blamed on members of Polish resistance groups, providing the official cause for World War II. The station survived World War II without bigger damages.
Mediumwave broadcasting transmissions were shut down in 1955. The tower was used until the middle Eighties to jam the signals of RFE. Nowadays it is used for mobile phone services and for low power FM-broadcasting. Since the end of 2004 the transmitter building is used as a museum.
Further information to its history:
http://en.wikipedia.org/wiki/Radio_Tower_Gliwice
http://radiopolska.pl/portal/staticpages/index.php?page=wykaz-archiwum-am
http://en.wikipedia.org/wiki/Attack_on_Gleiwitz_radio_station
137 kHz OK/MA QSO
Posted by John Andrews on October 29, 2005 at 15:23:11.
Laurence Howell, KL1X/WD2XDW, and John Andrews, W1TAG/WD2XES, had a 2 hour, 15 minute QSO on 137.422 kHz on Friday night (29 October, 0015-0230 UTC), over a path of 1340 miles. The WOLF operating mode was used. Details may be found at the W1TAG website.
John Andrews, W1TAG/WD2XES
potrzebie