Re: LF Ham Band
Posted by William C. Walker on June 01, 2002 at 07:30:24
As long as it does not take over any portion of the part 15, 160 to 190 band I'd be in favor of it.
PBJ back on air with repaired antenna
Posted by Chris Waldrup on June 02, 2002 at 19:04:20
I am back on the air with PBJ with a repaired antenna. The windstorm several weeks ago snapped the ceramic dogbone center insulator (interestingly, the soldered splices that I had added to lower the resonant frequency of the antenna held!. A new antenna was cut to the exact length of the old antenna with no splices. The wire for the antenna is insulated #14 solid house wire from Home Depot.
The ladder feed line (1960's vintage from my grandfather's old TV installation) peeled back about 4 feet so a new piece had to be cut and spliced into place. Upon recommendation of Paul Stroud, AA4XX, the wires no longer bear the weight- the antenna is cable tied to a rope between the trees.
If anyone wants to listen to tell me if the new antenna is functioning properly I will send a QSL card as always. Sending PBJ at QRSS6 on 13.55787.
Thanks.
Chris Waldrup KD4PBJ Apex, NC Grid FM05
185.3 June 3
Posted by lloyd chastant on June 03, 2002 at 08:14:09
Had several reasonable captures of the trio from 9PM to midnite(Local)but nothing after that....de Lloyd W3NF FM19MH
WA screen captures June 7
Posted by Mitch VE3OT on June 07, 2002 at 10:52:28
Bill:
Great overnight signals into London at 532 miles,
as the band kept quiet all night. The screen captures located on http://technology.fanshawec.on.ca/tele354
73 Mitch
Re: WA screen captures June 7
Posted by lloyd chastant on June 07, 2002 at 11:43:55
Mitch, couple of questions--The captures you show seemed to be at QRSS60 but your note says QRSS30-which is what the guys are running--Of course there is nothing wrong with trying at the QRSS60 mode HI!!!
and I notice that your sensitivity setting is at the 7 scale from the left--wonder if you have tried using setting 5 from left to cut down on some of the background noise and that should not cut down on the signal too much--Just a thought??
Re: WA screen captures June 7
Posted by Mitch VE3OT on June 07, 2002 at 13:34:10
Hi Lloyd:
Now you've caught me ! You are right - Argo was set up for QRSS60 - so I could have nice one hour captures.
Then I forgot to change the text on the description.
I use the same text for all the Web site info -- and just edit for each differnet day...... and change from QRSS30 to 60 and sometimes forget.
I think I left the sensitivity set up high from some previous testing I was doing.... I know that I have dropped it way back ( as you suggest) and the signal is still solid. At times the "green" level is just off the bottom and I am still copying okay.
Thanks for the suggestion. I'll do some testing this weekend. I wish we had some more targets in different directions.
It will be interesting to see how Bill appears to you this weekend as he switches to the N/S loop.
73 Mitch
Re: WA screen captures June 7
Posted by Mitch VE3OT on June 07, 2002 at 13:40:11
Lloyd:
Check the site again - - - after reading your e-mail I checked the Web site captures, and found I had "called up" the wrong day's pictures.
They should be correct now..
http://technology.fanshawec.on.ca/tele354
Thanks for the e-mail.
Mitch
Re: WA screen captures June 7
Posted by lloyd chastant on June 07, 2002 at 15:52:52
Yes sometimes we are just to loaded down with data ,Mitch..so no big deal..HI!!
I will be checking this weekend to see how the NS antenna looks..
Lloyd W3NF
WWVB on 60kHz - anyone fairly local willing to record it?
Posted by Lee Reynolds on June 07, 2002 at 18:42:53
Hi.
Is there anyone that's within a fairly short distance of WWVB that could be so kind as to make a three minute recording of the time signal for me?
If you're willing to help, please email me and I'll get back to you with the specs for the sound bite.
Thanks, Lee
Re: LF Ham Band
Posted by Jonathan Smick on June 08, 2002 at 03:58:44
I'll second that.
However, it should be noted that there are Lowfers who want 160-190 kHz to become allocated to the amateur service, some of whom may be commenting to FCC re this issue as FCC has asked for comments specifically on this point. See the thread "1750m counter proposal?" further down the list.
As it stands now, the 136 kHz (2200 meter) band will be allocated to amateur, the Part 15 160-190 kHz (1750 m) band won't. That is perfectly satisfactory and benefits both services. However, it seems that there are some who feel that 136 kHz is not enough. The fact that FCC has asked for comments re: 160-190 indicates a willingness on their part to listen to proposals and thus the case is not entirely closed as such.
The time to act is now, let your voice be heard before it is too late. The FCC will consider cogent, well-thought out comments. The comment period window closes at the end of this month. With higher power amateur signals allowed on the 1750 m band, the kind of freedom of experimentation, beaconing and broadcasting we now enjoy will be a thing of the past. While Part 15 may continue to "share" the band, this issue is not at stake. What is at stake is the likelihood that such "sharing" will almost certainly by default lead to the demise of Part 15 LF operations as we currently know them, as amateurs (or any licensed service) would have priority over Part 15 operations. This may mean that Part 15 stations would have to cease operation or change frequency every time they are perceived as "interference" by a ham wanting to use the frequency. In some cases, the Part 15 operator may have to cease transmitting altogether if they cannot find a clear frequency or cannot move because of difficulty or cost of doing so. Choosing to operate LF as a ham (if so licensed) won't be an option if one expects the same latitude as is now enjoyed under Part 15 as one can expect under amateur rules much stricter regulations concerning permitted emission modes, bandwidths and other aspects of operation. Beaconing under amateur regs. is unlikely to be permitted. Broadcasting in any form without doubt would be prohibited altogether.
Jon
remove "eat.spam." in email to reply
60 kHz broadcasting questions
Posted by J. Jason Wentworth on June 08, 2002 at 04:51:34
Hello All,
I have a few unusual questions regarding broadcasting at 60 kHz. I bought a Topix atomic clock, and as I feared, it can't receive WWVB here in Fairbanks, Alaska. I'll build an inductive loop antenna to remedy this, but another notion struck me.
Would it be possible (or even legal) to re-broadcast WWVB locally at 60 kHz (feeding from their online clock feature) using a low-power transmitter? If so, what antenna size and maximum RF output power are permitted for license-free 60 kHz broadcasting?
Many thanks in advance to anyone who can help. -- Jason
Signals from the NorthEast
Posted by Mitch VE3OT on June 08, 2002 at 10:08:22
Good morning:
Good, quiet conditions last night and nice screen captures from Jay ( VD ) and just a tiny trace of Bill (WA) on 185.3 kHz. Bill has switched to N/S loop, so interesting to compare signal strength - when copmpared to June 7th captures.
http://technology.fanshawec.on.ca/tele354
73 Mitch VE3OT
Re: Signals from the NorthEast
Posted by lloyd chastant on June 08, 2002 at 10:19:28
Pretty much the same on the captures last nite here in Maryland..will snd them along..
de Lloyd W3NF
Re: 60 kHz broadcasting questions
Posted by Udo Maier on June 08, 2002 at 12:37:03
You would produce a terrible signal, if you rebroadcast on 60 kHz.
The signal of your transmitter will get in your receiver and the result is a terrible feedback!
You have to use another frequency and you have to check very carefully that your output signal does not get in your receiver!
Do not forget on "Alexanderson day" (transmission of SAQ on 17.2 kHz)
Posted by Harald on June 08, 2002 at 12:38:37
Do not forget to receive the transmissions of SAQ on June 30th, 2002 ("Alexanderson day") on
17.2 kHz from 8:30 UTC to 8:45 UTC and from 12:30 UTC to 12:45 UTC (http://www.alexander.n.se/sa6q2002/)
Re: 60 kHz broadcasting questions
Posted by Tim Brannon KF5CQ on June 08, 2002 at 20:19:16
Jason,
Have you tried using just a random wire antenna? Maybe put up a random wire of about 100 feet or so, and at the clock wrap 4 or 5 turns around the clock's ferrite loopstick antenna as a coupling loop. Connect the shack end to a ground of some type. No need to tune it. That may do the trick, and its less trouble than a tuned inductive loop.
Tim
Re: 60 kHz broadcasting questions
Posted by J. Jason Wentworth on June 09, 2002 at 08:27:39
^Have you tried using just a random wire antenna? Maybe put up a random wire of about 100 feet or so, and at the clock wrap 4 or 5 turns around the clock's ferrite loopstick antenna as a coupling loop. Connect the shack end to a ground of some type. No need to tune it. That may do the trick, and its less trouble than a tuned inductive loop.^
Yes, but unfortunately it didn't work. It could be a case of local noise. -- Jason
Hifer RY back on the air.
Posted by John Andrews on June 09, 2002 at 11:19:29
I finally have Hifer RY back on the air, on 13555.37 kHz. QTH is Raymond, ME, FN43sv. The antenna is the same as last year, a vertical dipole, with the bottom end just a few feet above the ground.
Curent mode is QRSS3, and will remain that way for at least the next two weeks.
Reports would be appreciated, as my home QTH is too close to hear it except under unusual conditions.
John Andrews, W1TAG TAG 185.302 kHz RY 13555.37 kHz.
Comments Filed re RM-9404 136 KHZ band
Posted by Steve McDonald VE7SL on June 09, 2002 at 12:43:50
I urge you to file your comments before time runs out. In particular I have urged the commission to re-consider the 1W EIRP power level to the more realistic value of 1W ERP.
73 / Steve
File at their website:
http://www.fcc.gov/e-file/ecfs.html
WWVB and radio-controlled clocks
Posted by Tim Brannon KF5CQ on June 09, 2002 at 16:43:04
After reading Jason Wentworth's post about using his radio-controlled clock in Alaska, I found this page on the NIST website:
http://www.boulder.nist.gov/timefreq/stations/radioclocks.htm Especially interesting are the WWVB coverage maps shown for different hours of the day. You can actually see skip zones in parts of the pattern. I always imagined that the coverage was omnidirectional, but it appears much better to the south. Is the poorer coverage to the north (like Alaska) due to aurora?? Any comments on this?
Re: Hifer RY back on the air.
Posted by lloyd chastant on June 09, 2002 at 17:57:13
Just thought I'd take a quick look for RY this afternoon and there was a big signal at about 3PM local here in Maryland.
de Lloyd W3NF
Re: Do not forget on "Alexanderson day" (slight correction)
Posted by John Davis on June 09, 2002 at 19:35:57
According to word from Lars Kålland (SM6NM) the commemorative transmission will begin at 08:30 UTC and will be _repeated_ at 08:45 UTC, 12:30 UTC and 12:45 UTC.
John
Re: 60 kHz broadcasting questions
Posted by John Davis on June 10, 2002 at 02:33:27
Jason asks:
"Would it be possible (or even legal) to re-broadcast WWVB locally at 60 kHz (feeding from their online clock feature) using a low-power transmitter? If so, what antenna size and maximum RF output power are permitted for license-free 60 kHz broadcasting?"
Sorry, even if you could overcome the feedback problem Udo mentioned, the amount of signal allowed under Part 15 at 60 kHz is so low that most of your area would pick up more signal from the "real thing;" which, apparently, is already too low to do you any good.
John
Hifer RY and GA capture on same Argo screen
Posted by lloyd chastant on June 10, 2002 at 14:15:07
Had a nice capture of Hifer RY and GA on the same Argo screen this afternoon in QRSS 3 mode.RY at 13555.36 and GA at 13555.55...
de Lloyd W3NF
Re: 60 kHz broadcasting questions
Posted by J. Jason Wentworth on June 10, 2002 at 18:26:06
I wouldn't use a radio receiver to get the WWVB signal for local re-broadcast. As I said in the initial post, I would use WWVB's *online* clock (with appropriate software to convert the ASCII to the WWVB pulse format), and this re-constituted signal would be broadcast through a local low-power 60 kHz transmitter. What antenna length and transmitter power are permitted at 60 kHz?
Radio-controlled clocks and watches receiving the re-broadcast local 60 kHz signal could be off by a few seconds because WWVB's online clock varies a bit depending on internet bandwidth usage. However, since we have *no* accurate time reference in Fairbanks (public outdoor clocks in town vary from each other by as much as 8 minutes!), such a "local WWVB" would be a great improvement over what we now have. -- Jason
Re: 60 kHz broadcasting questions
Posted by John Davis on June 11, 2002 at 01:59:20
:: I wouldn't use a radio receiver to get the WWVB signal for local re-broadcast. As I said in the initial post, I would use WWVB's *online* clock (with appropriate software to convert the ASCII to the WWVB pulse format), and this re-constituted signal would be broadcast through a local low-power 60 kHz transmitter. ::
OK, I see now. The use of the term "rebroadcast" is what was throwing us off.
:: What antenna length and transmitter power are permitted at 60 kHz? ::
I hate to be the bearer of bad news, but it doesn't work that way at 60 kHz. Outside of a limited handful of bands such as 160-190kHz and 510-1705kHz, the permissible radiation of a Part 15 device is determined by actual field strength.
Section 15.209 is the relevant portion of the Rules. Between 9kHz and 490kHz --minus a spurious-only slot centered on the LORAN frequency-- the formula specifies no more than 2400/F microvolts per meter (where F is the frequency in kilohertz) as measured at a distance of 300 meters.
Doing the math, 2400/60 = 40. So, you would be limited to 40uV/m of field strength...interestingly, about the level a good radio-controlled clock needs in a moderately quiet area. But the bad news is, that's only permitted up to 300 meters (roughly 1000 feet) from your antenna.
John
LW Receiver available
Posted by William C. Walker on June 13, 2002 at 14:54:57
Here's something you don't see every day. Last year I purchased a Cambridge Audio Integrated Amplifier for my stereo system. Today I received their current catalog and it contains a Tuner, model T 500 that has Long Wave frequencies of 153 to 279 in addition to the standard AM and FM bands! This unit is available in the USA.
http://www.cambridge-audio.com
Hifer trio-MP,GA,RY copied
Posted by lloyd chastant on June 13, 2002 at 21:54:48
Had a nice single frame Argo showing Hifer MP, GA and RY here in Maryland this morning...
de Lloyd W3NF
Re: LW Receiver available
Posted by Jonathan Smick W2MXW on June 14, 2002 at 20:17:05
How's about a car radio with longwave? An extensive internet search coughed up many models of car radios, clock radios, walkmans, pocket radios, table radios, and more, all with LW coverage but unfortunately mostly only available in the UK and elsewhere in Europe. However I did find a few LW auto models available in the USA (and much cheaper than the well-known Becker!) from Alpine, Denon and Sony:
Alpine CDM-7857 CD/AM/FM/LW, Bass Engine, 40wx4, wireless remote ready, subwoofer control, pre-outs, detach face. $249 US.
Sony XPLOD CDX-CA850X CD/AM/FM/LW/SW, LW/AM/SW sensitivity 30 microvolts, 52wx4. $269 US.
The above 2 can be purchased from http://www.onlinecarstereo.com
Sony XPLOD XCD-300PKG Car Audio Package:
CD/Cassette/LW/AM/FM/SW D-Bass, 30 microvolts sens. on AM/LW/SW, CD Text, 50wx4, pre-outs, detachable faceplate. $270 US. Available from http://www.simplycheap.com
Denon DCR-470RD Cassette/AM/FM/LW, CD changer control, RDS, detach faceplate, 30wx4, pre-outs, a whopping 1.0 uV sens. on FM and 20 uV AM/LW. $79 US.
The above is a refurb w/90-day warranty and available from http://www.spidergear.com
No doubt there are others and a thorough search of a large site like Online Car Stereo would likely prove fruitful.
On another note I recently purchased the Coby CX-CB12 LW/SW/AM/FM "pocket" radio mentioned by someone further down on the board, and it is pretty much deaf as a post on LF (although it does pretty well on AM/FM and the sound quality is surprisingly good). Hey, whaddya want for $15?? An inductively coupled LW loop (like an LF version of the Select-A-Tenna or Terk, or my homebrew active ferrite rod antenna) would be needed to improve things on LW as it uses an in-built ferrite core loopstick for the band and has no external antenna jack (and I don't know if there is such a product available commercially for LW). Either that or it would have to be modded for a jack so it could accept an LF active antenna (which are available from LF Engineering among others). Using it as-is, I can only hear one strong NDB around 246 kHz and of course Nantucket powerhouse TUK on 194 kHz (which can probably be heard on fillings :-) while on another not-too-expensive AM/FM/LW/SW portable radio I have I can fill all the memory presets on LF with low power NDBs and have some left over, without resorting to external antennas. And this latter radio is not even the best on LW I've ever seen by far.
Jon
remove "spam.slasher."
Re: Comments Filed re RM-9404 136 KHZ band
Posted by george on June 15, 2002 at 14:02:00
The NPRM was finally published yesterday in the federal register. "Written comments are due July 29, 2002, and reply comments are due August 13, 2002".
(From the Federal Register contents at www.gpo.gov):
ACTION: Proposed rule.
SUMMARY: This document proposes to amend the Commission's Rules to add a new secondary allocation to the 135.7-137.8 kHz band for the amateur service for experimentation in the low frequency (``LF'') region of the spectrum; add a new secondary allocation to the 5250-5400 kHz band for the amateur service to facilitate high frequency (``HF'') amateur service operations; and to upgrade the amateur service allocation from secondary status to primary status and add a primary allocation for the amateur-satellite service in the 2400-2402 MHzband. The proposed changes to the Rules would enhance the ability of the amateur service to conduct technical experiments with LF propagation and antenna design; allow amateurs to communicate at 5250 kHz when propagation conditions do not permit communication at 3500 kHz or 7000 kHz; and provide protected status for the amateur-satellite service now using the 2400-2402 MHzband.
DATES: Written comments are due July 29, 2002, and reply comments are due August 13, 2002.
FOR FURTHER INFORMATION CONTACT: Kathyrn Medley, Office of Engineering and Technology, (202) 418-1211, TTY (202) 418-2989, e-mail: kmedley@fcc.gov.
ADDRESSES: All filings must be addressed to the Commission's Secretary, Office of the Secretary, Federal Communications Commission. Filings can be sent by hand or messenger delivery, by commercial overnight courier, or by first-class or overnight U.S. Postal Service mail (although we continue to experience delays in receiving U.S. Postal Service mail). The Commission's contractor, Vistronix, Inc., will receive hand-
delivered or messenger-delivered paper filings for the Commission's Secretary at 236 Massachusetts Avenue, NE., Suite 110, Washington, DC 20002. The filing hours at this location are 8:00 a.m. to 7:00 p.m. All hand deliveries must be held together with rubber bands or fasteners. Any envelopes must be disposed of before entering the building. Commercial overnight mail (other than U.S. Postal Service Express Mail and Priority Mail) must be sent to 9300 East Hampton Drive, Capitol Heights, MD 20743. U.S. Postal Service first-class mail, Express Mail, and Priority Mail should be addressed to 445 12th Street, SW, Washington, DC 20554.
SUPPLEMENTARY INFORMATION: This is a summary of the Commission's Notice of Proposed Rulemaking, ET Docket 02-98, FCC 02-136, adopted May 2, 2002, and released May 15, 2002. The full text of this document is available for inspection and copying during regular business hours in the FCC Reference Center (Room CY-A257), 445 12th Street, SW., Washington, DC 20554. The complete text of this document also may be purchased from the Commission's copy contractor, Qualex International, 445 12th Street, SW., Room, CY-B402, Washington, DC 20554. The full text may also be downloaded at: www.fcc.gov. Alternative formats are available to persons with disabilities by contacting Brian Millin at (202) 418-7426 or TTY (202) 418-7365.
Pursuant to Sections 1.415 and 1.419 of the Commission's rules, 47 CFR 1.415, 1.419, interested parties may file comments on or before July 29, 2002, and reply comments on or before August 13, 2002. Comments may be filed using the Commission's Electronic Comment Filing System (ECFS) or by filing paper copies. See Electronic Filing of Documents in Rulemaking Proceedings, 63 FR 24121 (1998). Comments filed through the ECFS can be sent as an electronic file via the Internet to http://www.fcc.gov/e-file/ecfs.html. Generally, only one copy of an electronic submission must be filed. If multiple docket or rulemaking numbers appear in the caption of this proceeding, however, commenters must transmit one electronic copy of the comments to each docket or rulemaking number referenced in the caption. In completing the transmittal screen, commenters should include their full name, U.S. Postal Service mailing address, and the applicable docket or rulemaking number. Parties may also submit an electronic comment by Internet e-
mail. To get filing instructions for e-mail comments, commenters should send an e-mail to ecfs@fcc.gov, and should include the following words in the body of the message, ``get form
Hifer TLTX 13.560 Mhz
Posted by Tony Levstik on June 15, 2002 at 14:27:35
I have put up a New antenna for my beacon. 1/2 wave longwire.
The beacon is still on the same frequency. 13.560MHz(13.55983MHzexactly).
QRSS3 and 45baud RTTY (Mark only)
Any signal reports are welcome.
Tony Levstik levstik1@worldnet.att.net
Other HiFER Updates
Posted by John Davis on June 16, 2002 at 13:11:10
In addition to the HiFER beacon updates on RY and TLTX in recent messages to this board, here are a couple of others from this past week:
Subj: Lowfer Beacon Update Date: 6/4/02 12:24:16 PM Eastern Daylight Time From: gauger@sympatico.ca (Gilles Auger)
To: part15@lwca.org
Hi
Beacon : GA Frequency: 13.55555 Mhz Mode: QRSS3 24/7 (06/03/02)
Location: Montreal, QC FN35fo Antenna: Quarter wave ground Plane This is a solar powered beacon.
VE2DRW
- - - - - - - - - -
Subj: HIFER Correction 13555.473 Date: 6/15/02 11:50:41 PM Eastern Daylight Time From: m_powell@sympatico.ca (Mitch Powell)
To: part15@lwca.org CC: Lowfer@mailman.qth.net
Beacon ID = MP Freq 13555.473 QTH London, Ontario
43N 81'15W Grid Location EN93ja London, ON. VE3OT
Notes Epson osc.
QRSS3 wpm
On the air 24/7
Vertical dipole Correction to Frequency.
Re: LW Receiver available
Posted by William C. Walker on June 16, 2002 at 17:16:39
I purchased one of the Coby units and was dissatisfied with the selectivity of the unit on MW when it had any local stations nearby. However we discovered the sensitivity of the unit is fair after being able to listen to a part 15 AM station loud and clear at more than one quarter of a mile away in an area with poor ground conductivity. We are going to set up a part 15 LW station this Fall and try the Coby out to see how far away it will pick up the station. I'll reserve judgment of the unit until the tests are complete.
There are a number of multi band radios that contain LW in the USA. But it is good to hear that you can purchase a car stereo that also contains the LW band. I was shocked to see that Cambridge Audio has a hi grade stereo tuner with LW available for the USA. I may have to pick that unit up at some point in the future.
Hifer NC copy in Maryland
Posted by lloyd chastant on June 17, 2002 at 10:11:53
Had a nice capture this morning on NC at 13555.50 and GA was having only marginal signal at 13555.45..Seemed likew there was plenty of fading..Only monitored for a few minutes..
de Lloyd W3NF
Some interesting VLF Signals
Posted by Jay Flynn on June 17, 2002 at 13:28:55
I live in Los Angeles and have been monitoring a couple of interesting VLF signals.
On 21.1 kHz I have heard the intermittant MSK signal round the clock. In my local afternoon, around 2300-0000Z, this station sends in MORSE, "U U U U RDL RDL" followed by 5 number groups. It may make only one or two morse transmissions per day. The signal is pretty readable as long as the local noise is low. The old hands probably recognize the call sign as that of the Russian military.
On 19.65, just below NWK Australia is a signal I have never seen before. It is a 2 second pulse with a 54 second interval between pulses. Any ideas?? I just wnat to be sure it isn't anything local. Anyone else even hear it???
Thanks Jay
Re: Some interesting VLF Signals
Posted by Mike KB6WFC on June 17, 2002 at 19:37:37
Hi Jay & the rest,
Thanks for tip on RDL on 21.1kHz.
I haven't looked for the pulse signal you mentioned but perhaps this site may help you identify it if you don't know of it already:
http://web.tiscali.it/vlfradio/trond2/list.html
73 de Mike KB6WFC ..
Re: Hifer NC copy in MA, too
Posted by John Andrews on June 17, 2002 at 21:39:26
Had some scratchy copy of NC around sunset tonight. Got one complete call sign, but things were pretty choppy with local T-storms. Right on frequency, though.
John Andrews
Re: LW Receiver available
Posted by Jonathan Smick on June 18, 2002 at 03:09:34
The Coby is indeed pretty darn good on AM BCB sensitivity-wise. A good radio for that purpose, esp. since the Rat Shack 12-201 pocket radio I was recommending was discontinued. But I tell ya, the LF section bites. You'll see. Try tuning in some NDBs, bet you don't get more than one or two locals. Either that or I got a lemon??? :-(
I'm considering one of the car radios myself. It'd be sooo cool to be able to drive around and listen to LF without having to use a multiband portable and a snarl of cables.
That Cambridge seems like a goodie too. Appreciate your bringing it to our attention. Probably made for a world market, and it would cut down on inventory and mf'g costs to have just one model, instead of having to purposely omit the LW tuner for US sales.
Fine biz on the LW station plans. I'm building my ATU now, just finished the monster coil. Man do I have carpal tunnel from all that winding! :-)
Jon
remove "smackdown.the.spam."
Re: Some interesting VLF Signals
Posted by Harald on June 19, 2002 at 06:22:14
Does your signal on 19.65 kHz look like this on http://lwca.org/mb/msg/pix/gbz10feb02.jpg?
The GBZ transmitter in Criggion, UK sometimes send strong single pulses.
ZL6QH Test postponed
Posted by Bob Vernall on June 19, 2002 at 20:42:38
Subj: Test postponed Date: 6/19/02 3:58:02 PM Eastern Daylight Time From: vernall@xtra.co.nz (Vernall)
To: LWCANews
Hi,
I earlier advised that ZL6QH would be transmitting on 137 kHz on Saturday 22 June. Various constraints have arisen and consequently the test this coming weekend is postponed. Possible dates are 17 August and/or 21 September.
73, Bob ZL2CA
Re: LW Receiver available
Posted by William C. Walker on June 19, 2002 at 23:21:02
What other LW radios are you using for listening purposes? You mentioned another unit that outperformed the Coby on LW. Which model and make?
Keep us aprised of your LW station success. I'd especially like to find out what kind of range can be had when using the Coby for reception purposes. One of my technicians seems to think the Coby could pick up a properly tuned part 15 LW playing music or talk up to five miles away.
"Tweeker" Receiver
Posted by Frank Carson on June 20, 2002 at 09:02:44
DOes anyone have any experiance with the VLF receivers sold by "Stormwise"? They are the "Tweeker" and "SAU-444B VLF Magnetic Field Receiver?" They look interesting - and appear to be well made and durable. Any input would be appreciated. Thanks
Frank Carson N3OCW
TAG Moves for the Weekend
Posted by John Andrews on June 20, 2002 at 21:02:08
TAG is now transmitting in Jason mode on 185.402 kHz. I will be doing a little research with it over the weekend, and will rejoin the other loopers on Monday.
John Andrews, W1TAG TAG & RY Status: http://webpages.charter.net/w1tag/
Cool find - US Navy VLF station paper
Posted by Jonathan Smick on June 21, 2002 at 02:01:03
I just found this gem while searching. It is a paper describing in detail the Navy's Cutler, ME VLF installation mainly with respect to problems they have with the topload system. Goes into some detail on the deicing system, corona starting voltages, tophat design for all three VLF frequencies (14.0, 17.8 and 24.0 kHz). Fascinating stuff. Download at:
www.spawar.navy.mil/sti/publications/ pubs/tr/1681/tr1681.pdf About 1.6 MB, PDF format.
Enjoy!
Jon
remove "nary.a.spam."
Folded Marconi antenna information
Posted by J. Jason Wentworth on June 21, 2002 at 03:16:33
Hello All,
I've been reading about a good MW and SW antenna that should also work well (when cut to the appropriate length, of course) for LW: the Folded Marconi antenna. For LW transmitting, it can be used with a loading coil and a top hat to stay within the 15 meter height limit.
The Folded Marconi (see below for more information) can be mounted as a vertical or as an Inverted-L. When configured in those two ways, its radiation pattern is the same as those two types of single-conductor antennas.
For LW in particular, the Folded Marconi antenna has the advantage that its multiple parallel conductors create a ^transformer action^ that increases the antenna's feedpoint impedance. It increases with the square of the number of conductors (a two-wire Folded Marconi has 4X the feedpoint impedance of a single-wire antenna, a three-wire Folded Marconi has 9X the single-wire antenna impedance, etc.).
The 300 ohm TV-FM twin lead and 450 ohm ladder line make *excellent* Folded Marconi antennas. The Folded Marconi works very well for Short Wave reception, long-distance AM reception, and transmission & reception on the 160 meter and 80 meter Ham radio bands.
Below is more information on the Folded Marconi antenna (also called a Twin-lead Marconi and a Folded Unipole). It is *very* easy to make from 300 ohm twin lead TV-FM transmission line or 450 ohm ladder line (see below for building instructions and a list of its advantages).
The Folded Marconi antenna is a two-conductor, grounded Marconi antenna that is electrically closed like a loop antenna, so it doesn't gather a static charge in high winds or snowstorms (the static charges are bled off to ground). It also has four other advantages:
(1) The Folded Marconi antenna does not have to be entirely vertical to work well--it can work well with a substantial horizontal section just 30 feet high.
(2) The Folded Marconi antenna is half of a folded dipole, and like the folded dipole it is a broadband antenna. It can cover most (if not all) of the 160 kHz - 190 kHz LowFER band without an antenna tuner. Ham radio operators have also noted this broadband characteristic in their use of the Folded Marconi on their bands.
(3) Because of its broadband characteristic, the Folded Marconi antenna does not have to be cut to *exactly* the correct 1/4 wavelength size to work well.
(4) Being a grounded antenna, the Folded Marconi is less likely to attract lightning strikes because it bleeds off static charges to ground.
(Because of these advantages, many AM broadcast stations are converting their series-fed towers to Folded Marconi antennas by adding top-suspended vertical ^fold wires^ hanging next to the tower. LBA http://www.lbagroup.com/technology/tunicomb.htm makes and installs these ^Tunipole^, ^Combipole^, and ^Colopole^ tower modification kits.)
To make a Folded Marconi antenna from 300 ohm TV-FM twin lead or 450 ohm ladder line, the twin lead is cut to 1/4 wavelength of the desired frequency. The far ends of the twin lead are shorted together. At the receiver end, one of the twin leads is connected to a 50 ohm coaxial cable (its center conductor). The adjacent twin lead is connected to the coax braid. This coax braid/twin lead junction is then grounded to either: [1] a radial system of four 1/4 wavelength (actually 3% longer) radial wires, or [2] connected to a counterpoise (1/4 wavelength of insulated wire) mounted 1 foot above the ground.
A simple modification to this basic Folded Marconi antenna (see below) will improve its efficiency. The two twin lead conductors act like a 4:1 transformer, which increases the antenna's impedance to ~50 ohms. This makes the antenna match well with the standard 50 ohm inputs and 50 ohm outputs on receivers and transmitters, respectively.
(To raise the usually low LW antenna impedance higher, two or more lengths of 300 ohm twin lead or 450 ohm ladder line could be strung up in parallel and shorted together at their far ends. At the receiver end, two ^bundles^ of opposite leads would be connected to the 50 ohm coaxial cable and to the ground radials or counterpoise as before.)
This transformer effect works best when the twin-lead is cut to a length of 1/4 wavelength times the velocity factor of the twin-lead (0.88). The far ends are shorted together as before, and the length is extended to 1/4 wavelength by attaching a single wire of the remaining length to the shorted end.
For example, for an antenna made for 1.6 MHz, the 1/4 wavelength is (234/1.6 = 146.25 feet). Now 146.25 feet x the velocity factor of 0.88 for 300 ohm twin lead = 128.7 feet. So, cut 128.7 feet of 300 ohm twinlead, short one end together and extend this shorted end to 146.25 feet with flexible wire. (With 450 ohm ladder line, the line can be cut to 1/4 wavelength [146.25 feet] and then be shorted together at the appropriate ^ladder line velocity factor distance^ from the receiver end.)
At the receiver end, one of the twin leads is connected to a 50 ohm coaxial cable (its center conductor). The adjacent twin lead is connected to the coax braid. This coax braid/twin lead junction is then grounded to either: [1] a radial system of four 1/4 wavelength, 146.25' (actually 3% longer) radial wires, or [2] connected to a counterpoise (1/4 wavelength [146.25'] of insulated wire) mounted 1 foot above the ground.
I hope this information will be helpful. -- J. Jason Wentworth
Re: LW Receiver available
Posted by Jonathan Smick on June 21, 2002 at 03:39:06
Will,
The portable I was referring to is the Realistic DX-399 (discontinued). I believe they have another model now to take its place. Radio Shack's multiband radios are mostly made by Sangean. Sorry, I don't know the Sangean equivalent model # for this one. It is halfway decent, not the most sensitive radio for LF by far, but it beats the pants off the Coby. (Of course, it also cost $80, which although not all that much for a PLL multibander, hence my comment that it isn't "too expensive", it's still much more than the Coby). I'd tend to think 1/2 to *maybe* 1 mile max. is more likely with the Coby. I was quite disappointed considering I got it for the LW coverage (figured if it was good I could use it as a "beater" to carry around and not worry about breaking/losing it), plus I wanted to see if it would be viable to recommend for distribution to the public.
BTW I will be posting a link to your LPAM site when I finish the updating of the "Master List" (whenever that is!)- nope, haven't forgotten you!
Jon
remove "ham.without.spam."
Re: Folded Marconi antenna information
Posted by John Davis on June 21, 2002 at 21:37:35
Sorry to be the bearer of bad news, but it does not appear possible to build a true folded Marconi within the limitations of Part 15. Not even the generous "15 meter cylinder" interpretation.
We had someone several years ago who "invented" an antenna that matched your description, with loading coils to attempt to lengthen the elements. After a number of cyptic hints but few details (he was going to patent it, supposedly) it went away quietly.
Literally. No one ever heard a signal out of it.
Basically, 15 meters is such a small fraction of 1750 meters that all you end up with is a series of loading coils. The transformer effect does not take place for the radiation resistance...at least, not enough to overcome coil losses.
One other note about the LBA Tunipole: a folded unipole is more correctly a shorted transmission line transformer than it is a folded Marconi. Similar principle so far as, BTW transformation goes, but a bit different in how it actually radiates.
I have some personal experience with one of their systems. An AM station allowed a cellular operator to replace their quarter-wave vertical with a huge 3-leg self-supporter, fed by a folded unipole skirt system. Problem was, LBA initially designed the skirt to work against the face of the tower, not the legs. Terrible results! After one redesign to place the skirt ways off the legs, they still did not take the tapered cross section into account. Really, really lame bandwidth and dangerously unstable impedance with weather changes!
Fortunately, a local consultant redesigned the system taking the taper into account, and achieved much more satisfactory matching to the transmitter.
John
Re: Folded Marconi antenna information
Posted by J. Jason Wentworth on June 21, 2002 at 23:42:46
OOPS! Let's try that again...
John Davis wrote:
^Sorry to be the bearer of bad news, but it does not appear possible to build a true folded Marconi within the limitations of Part 15. Not even the generous "15 meter cylinder" interpretation.^
I don't understand. I thought the 15 meter length limit only applied to transmitting antennas, not receiving antennas. A 1/4 wavelength Folded Marconi for LowFER reception would be pretty long, but there are MW DXers who build multi-wavelength beverages of comparable length.
The transformer action of the Folded Marconi would raise the feedpoint impedance to better match a receiver, and because it is a grounded antenna it should reduce or eliminate ^antenna static build-up noise^ that can be heard when using a single-conductor Inverted-L wire antenna. -- Jason
Using NDBs for ground/road navigation?
Posted by J. Jason Wentworth on June 22, 2002 at 03:27:02
Hello All,
I've been listening to my local LF Non-Directional Beacons since I picked up one of the Coby LW/SW/AM/FM radios, and an idea occurred to me.
The FAA may well be re-thinking the wisdom of shutting down the NDBs since 9-11. With the threat of terrorist mischief toward aviation, it seems inadvisable to eliminate cheap, reliable, and numerous back-up navaids such as NDBs.
Having listened to my local NDBs (one of which also broadcasts aviation weather reports) on my cheap Coby receiver, I think these beacons would also be useful for ground navigation while hiking or driving. Using (1) a cheap receiver with an internal directional loopstick antenna and (2) a map marked with the NDB positions, frequencies, and morse code identifiers (they're slow enough that anyone could match what they heard with the printed dots and dashes), it would be easy to determine one's position (or at least one's direction of travel). Also, the voice weather reports broadcast by some NDBs would be helpful to motorists on long road trips.
Have any of you ever used NDBs in these ways? For surface travel, they could be a cheap but effective substitute or back-up for GPS. -- Jason
Hifer Quad Copy NC,MP,GA ,RY
Posted by lloyd chastant on June 22, 2002 at 09:17:43
Have seen three of the four Hifers but had not captured all four until this morning..Nice Spectran capture of the four here in Maryland..de Lloyd W3NF FM19MH
(Click the image above to open a full-size screen capture.)
Re: Folded Marconi antenna information
Posted by John Davis on June 22, 2002 at 10:46:25
Jason writes: "I don't understand. I thought the 15 meter length limit only applied to transmitting antennas, not receiving antennas. A 1/4 wavelength Folded Marconi for LowFER reception would be pretty long, but there are MW DXers who build multi-wavelength beverages of comparable length."
True. However, I was commenting on your first paragraph, which does make reference to Part 15 requirements:
"For LW transmitting, it can be used with a loading coil and a top hat to stay within the 15 meter height limit."
John
Re: (Corrected URL) Cool find - US Navy VLF station paper
Posted by Webmaster on June 22, 2002 at 13:12:58
Readers who have tried to access the URL contained in Jonathan's post by copy-and-paste have probably encountered a "file not found" error message. There is an extra space as written. It should be:
www.spawar.navy.mil/sti/publications/pubs/tr/1681/tr1681.pdf
(no space before "pubs")
If we LowFERs ever get to thinking we have unique problems putting up antennas sometimes, this article will give us a new perspective. :-)
John
Best Long Wave Receiver
Posted by michael on June 23, 2002 at 22:25:48
I am looking for a good lw/mw/sw receiver, and one of the requirements would be excellent long wave reception.
Thank You,
Michael
Re: Using NDBs for ground/road navigation?
Posted by Harald on June 25, 2002 at 18:03:35
A good idea! But why not to use mediumwave broadcasting transmitters? For many people broadcasting transmitters are easier to identify and they use much higher power then NDBs(until 50 kW in USA and until 2500 kW in Europe).
It is much more ecconomic to run a broadcasting transmitter with high power. Operation of transmitters is for big companies "Peanuts", when they are financed by the government or commercially by advertising!
For big bróadcasting companies costs for running the transmitters are 10 % of the whole costs or lower)
In Europe we can also use longwave broadcasting transmitters for this purpose. Since they have powers in the range between 100 kW up to 2000 kWs and frequencies between 148 kHz and 283 kHz, they are best for this purpose!
(Of course VLF transmitters can be also used, but you need a bigger or heavier coil. Or you use a separate coil which you connect to the soundcard input of a handhold PC with an analyss software as "SpecPlus")
I sometimes use the method of direction finding with an AM radio in the woods. I use therefore my self - built receivers for long- and mediumwaves, which use ferrit coils as aerial in order to find my way. (I live in Germany, so I can take benefit of longwave broadcasting transmitters)).
This method works well, but I use broadcasting stations not NDBs. NDBs are a bit too weak and broadcasting stations also offers informations, news and music...
Re: Hifer Quad Copy NC,MP,GA ,RY
Posted by lloyd chastant on June 25, 2002 at 19:08:22
Had a nice HiferFour this morning(about 10AM) with the NC sawtooth at a higher rate.Conditions seem to have been sorta poor in last couple of days--may be this very hot/humid spell we are having :)..can send a copy of the Spectran capture if anyone wishes to see it..
de Lloyd W3NF
Re: Using NDBs for ground/road navigation?
Posted by Jonathan Smick on June 26, 2002 at 02:18:25
I don't see why not. I wonder if one could take it a step further and use one of the moving ferrite loop radiocompass antennas (Surplus Sales or somebody had them) which would actually show your heading with respect to the NDB. These antennas cover 190-530 kHz, the whole LF/MF beacon band. They came right out of aircraft. Was pondering the purchase of one, and this could be a good application for it (besides tracking down NDBs hehe). Or am I getting ahead of myself in typical engineer fashion? :-) Heck, I even recently saw a GPS handheld (Magellan 315) for sale that includes a built-in NDB database. Displays the 20 nearest NDBs to your location, and gives frequencies. The ultimate NDB DXer's buddy!
Not perhaps directly cogent to what you asked but as a fellow Coby owner I was wondering how you would rate the performance on LF?
I found the unit to be seriously wanting in sensitivity as compared with even a relatively mediocre PLL multiband portable (RS DX-399).
Perhaps I have a lemon? Or do you find yours to be "deaf" on LF as well?
I was finally able to get it to perform okay - by using an external inductively coupled passive "assist" antenna (same idea as a Terk, etc.) except I used a ferrite rod, wound with #30 and tuned with a variable cap. NOW it can pull in the NDBs!
Jon
remove "master.spam.blaster."
DataTrak
Posted by Lawrence on June 26, 2002 at 02:22:57
Hello All, This is my first post here. I live in central England and my LF monitoring equipment consists of old domestic radios!
Here in the UK I can receive the DataTrak signals very strongly.(147-150 Khz, repetitive chirping sound). I wondered:
A- Is it possible and/or useful to decode these?
B- Where are the transmitters for this system?
Many thanks, Lawrence
Re: Using NDBs for ground/road navigation?
Posted by J. Jason Wentworth on June 26, 2002 at 09:03:50
Harald wrote:
^A good idea! But why not to use mediumwave broadcasting transmitters? For many people broadcasting transmitters are easier to identify and they use much higher power then NDBs(until 50 kW in USA and until 2500 kW in Europe).^
I have a nostalgic affinity for NDBs and older navaids such as lighthouses. Also, NDBs are cheap, reliable, and already available.
Jonathan Smick wrote:
^Not perhaps directly cogent to what you asked but as a fellow Coby owner I was wondering how you would rate the performance on LF?
I found the unit to be seriously wanting in sensitivity as compared with even a relatively mediocre PLL multiband portable (RS DX-399).^
On the Coby, I can hear the 25 watt Chena (CUN) NDB (with TWEB voice weather announcements) loud and clear on 257 kHz. This beacon is 9.5 miles away from me. I get it strongly using just the internal loopstick antenna.
^I don't see why not. I wonder if one could take it a step further and use one of the moving ferrite loop radiocompass antennas (Surplus Sales or somebody had them) which would actually show your heading with respect to the NDB. These antennas cover 190-530 kHz, the whole LF/MF beacon band. They came right out of aircraft.^
How much were these aircraft ADF loops? -- Jason
Re: Using NDBs for ground/road navigation?
Posted by Harald on June 26, 2002 at 13:09:47
Does the "Magellan 315" also include a database of the more powerful and therfore much easier receivable longwave broadcasting transmitters, longwave utility stations and VLF transmitter stations?
Because these transmitters operate with much higher power then NDBs, they would be more useful for terrestic navigation!
Hifer AZ QRSS6
Posted by Jim Mandaville on June 26, 2002 at 16:09:21
Hifer AZ, Tucson, Arizona, was switched from CW 12 wpm to QRSS6 24/7 today, 26 Jun 02. Freq. is 13554.45 (varies somewhat with temperature). Will run this mode until further notice. Any reports welcome.
Re: Some interesting VLF Signals
Posted by Jay Flynn on June 26, 2002 at 18:03:23
Thank you, Harald, but that signal appears to be a MSK signal. What I am hearing is a 2 second pulse repeating every 54 seconds. I don't know if I can receive GBR in Los Angeles with my system and the local noise.
I will keep monitoring and see if it changes with daylight or other conditions.
Re: Some interesting VLF Signals
Posted by Jay Flynn on June 26, 2002 at 18:08:11
Thanks, Mike. I checked there and found nothing that came close. I will keep listening. Around here it could be a computer, DSL, cable TV or even power line signals. Was just wondering if it is something from outside the area.
Re: Best Long Wave Receiver
Posted by Bill Ashlock on June 26, 2002 at 18:21:01
Michael,
I'd have to put in my vote for the Icom R75 with it's 1 Hz resolution and excellent frequency stability. After a 1/2 hour warm-up the drift is below .2 Hz (important for Lowfer QRSS copy) - even without the crystal oven option. Coverage is from 30kHz to 60MHzwith plenty of sensistivity over this range. The cost at about $500 is not that bad considering the features and performance. There's a Reflector group that can give you more positive comments at icomr75@yahoogroups.com. Since LF use is a major requirement I recommend purchasing the plug-in Icom 250Hz filter for the 9MHzIF stage.
Bill Ashlock
NC sawtooth copied in Texas
Posted by Tony Levstik on June 26, 2002 at 19:40:08
Got a good ARGO copy of beacon NC here in Sherman Texas.
Was also able to hear the signal through radios speaker.
Heres the Link for the Argo screen capture.
http://home.att.net/~levstik1/hifer.jpg
Tony Levstik levstik1@worldnet.att.net
Using GPS to Find NDBs!
Posted by John Davis on June 27, 2002 at 14:11:30
Saw this in the middle of your message, where it might get overlooked by a casual reader of this thread, and thought it was worth showcasing on its own:
"I even recently saw a GPS handheld (Magellan 315) for sale that includes a built-in NDB database. Displays the 20 nearest NDBs to your location, and gives frequencies. The ultimate NDB DXer's buddy!"
That's a _very_ cool idea!
John
SAQ Reminder
Posted by Webmaster on June 29, 2002 at 21:06:10
The Alexanderson alternator will operate four times this Sunday morning, beginning at 0830 UTC, as described on the lwca.org home page.
If you catch any of the transmissions, be sure to let us know here at the message board. Thanks!
John
Re: SAQ Reminder
Posted by Alberto di Bene, I2PHD on June 30, 2002 at 06:19:32
SAQ received in Northern Italy, using a (badly damaged) loop resonated with 220 nF, directly coupled with the sound card Line Input. Screen shots can be found at :
http://www.qsl.net/i2phd/spectran/images/saq_both.gif The left image reports the CW transmission, spread in frequency by the modulation sidebands, and the right image shows when the transmission ended.
Time reported is local time (UTC + 2). Unless my sound card's sampling rate is completely wrong, which shouldn't, the SAQ frequency seems to be a tad low, roughly 17190 Hz. Not bad for such an ancient device.
73 Alberto I2PHD
www.lwca.org
potrzebie