Re: USC Antenna
Posted by Pat Bunn on February 20, 2012 at 01:48:00.
In reply to Re: USC Antenna posted by John Davis on February 20, 2012
Re: DCF77 reception in the USA?
Great! I am curious what you think.
Thanks. EAR in PA
Posted by Rick KA2PBO on February 02, 2012 at 01:11:12.
I finally captured EAR ! I don’t know why I haven’t been able to in the past . We are only 350 miles or so apart. Thanks to Johns buffer/amp circuit from The Lowdown I got a small capture .I am using Lyles downconverter into the soundcard and no additional amplification .Hope I can snag a few more now that I have some new ears. Heres the link::
http://www.ka2pbo.com/ear2.jpg
73
Rick KA2PBO Hifers and Lowfers
Posted by Garry, K3SIW on February 02, 2012 at 18:47:09.
Deactivated the SIW hifer beacon briefly yesterday (Feb 1, 2012) around 1900Z to look for signals. Found NC on 13555590 Hz, square wave; USC on 13554017, QRSS3; EH on 13557010, CW; COM on 13557490, rect, and WV on 13555845, CW.
This morning "visual" lowfer WM was decent copy around 185.3 kHz, as were SJ, QRSS20 on 186.85 kHz and BR, CW on 185585 kHz. Nice to see LF propagation recovering after big solar events.
73, Garry, K3SIW, EN52ta, Elgin, IL
Re: Thursday HiFERs
Posted by Paul on February 02, 2012 at 19:25:21.
In reply to Re: Thursday HiFERs posted by Matt Burns on January 31, 2012
Yep!
The trick is to leave your beacon on all the time. make sure it is always there, just in case.
Some Hifer ops shut down during the "off season" for whatever reason. I leave mine on 24/7 and I get occasional reports year round. During the supposed "off season" when a bunch of other HiFers were off the air, I got mailed QSL reports from ZL and JA.
I still don;t understand why some ops shut down their HiFer beacons, it makes no sense to me. If a beacon is not reliable, then many people will stop listening for it. If they know your beacon is on 24/7/365, then they may try for it and get it!
Hifers today
Posted by Matt Burns on February 03, 2012 at 21:29:49.
I shut down COM for a few hours to listen for hifers today, I copied EH by ear about 559 at about 1900z, I also copied and was able to capture GNK at 1945z. GNK was much weaker but after a bit of patience I was able to copy by ear and get a decent capture. COM will resume operation momentarily.
73's, HiFers Heard 2 and 3 Feb., 2012
Matt Burns
kc8com
Posted by EdWSlidell,LA on February 04, 2012 at 02:50:51.
Hi. The conditions must have been fairly good yesterday, 2 Feb. during the 1310-1330 UT period, and later in the day from 2220 UT to 0200/3 Feb. Heard were WV around 449, EH about 339(unusually weak), AJO weak, but peaking to 339, and GNK upt to 559, all around 1300 UT. Later after 2220 UT, Also heard were SZX peaking about 229, and K6FRC(0200 UT) around 449--a station not heard for a while. Earlier stations were still there with exceptions of EH and AJO, which had both faded out. Today, after, 2200/3 Feb., WV, EH, SZX, GNK, and K6FRC were all heard. GNK and EH were both better than 559. EdWSlidell,LA EM50cg
HiFers 5 Jan., 2012
Posted by EdWSlidell,LA on February 05, 2012 at 13:52:47.
Some good propagation this morning during the 1315/1345 UT period, at least to north and east. WV on 13556 about 339, EH on 13557 a good 559, MTI just above on 13557.5 weaker, about 2/3 3 9, SZX on 13563 about 449, and GNK on 12564 a good 559, both despite SWBC on 13570 KHz. EdWSlidell,LA EM50cg
Hifers Sunday
Posted by Matt Burns on February 06, 2012 at 03:05:59.
Left the COM offline from about 0400-1700, no luck with qrss around 13555.4 but I managed to grab eh, szx, and gnk in cw.
I also tried listening for lowfers and medfers but no luck with the 20 meter dipole. If time and money permit I may build a converter and put up a longer antenna for lowfers and ndb's.
I did manage to log about 20 ndb's in the early morning hours, mostly from the south eastern US.
Matt Burns 472 Kc Amatuer Allocation
kc8com
Posted by Krystallo on February 06, 2012 at 13:58:12.
Hey All ,
See QRZ website for details.
K
Re: 472 Kc Amatuer Allocation
Posted by John Davis on February 06, 2012 at 18:51:06.
In reply to 472 Kc Amatuer Allocation posted by Krystallo on February 06, 2012
The phrase "major milestone" in their article is rather overstated, even though they copied that part verbatim from the ARRL site. A committee is finally resolving differences in the various proposals that we've been reporting on for a couple of years. No biggie. What will be news is if or when the remaining countries that don't want an allocation finally get on board. It'll be worth following the story in more detail on arrl.org (where you can read the original story QRZ was lifting from), as well as lwca.org and 500kc.com as the WRC progresses throughout this month.
Editorial Comment: It's interesting, if rather discouraging, however, to see the remarks below the QRZ piece from a number of...how shall I put it kindly...nitwits naysaying the idea because of the limited appeal of the power limits or the frequencies--apparently clueless that there already exist scores of hams around the world who have put in great effort to overcome regulatory hurdles and get NoV's or Experimental licenses, and who are now working quite successfully under those same limiting conditions.
"I don't have any interest in it, so I don't see why anyone else should, even though it's no skin off my nose nor one penny from my pocket. It has no effect on me whatsoever, but I'm shore gonna get riled up over it, by gum!"
If popularity were the only justification for doing something, we should all give up our ham tickets and beg the wireless Internet folks to take our existing spectrum, 'cause playing with iToys is what more people are into these days. --Oh, wait, they're already trying to take it anyway.
John
Re: 472 Kc Amatuer Allocation
Posted by pat bunn on February 06, 2012 at 22:20:15.
In reply to Re: 472 Kc Amatuer Allocation posted by John Davis on February 06, 2012
I thought it was particularly interesting that the "nitwits" considered 1 Watt ERP worthless.
I suspect that most of the lowfer guys wish they could operate with 1 watt ERP which is a bit different that 1 watt input. Just guessing that you could run a typical vertical antenna with 50-100 watts to get 1 watt ERP if you were lucky.
Pat
Re: 472 Kc Amatuer Allocation
Posted by Frtiz Raab on February 07, 2012 at 02:31:04.
In reply to Re: 472 Kc Amatuer Allocation posted by John Davis on February 06, 2012
What is important is getting an allocation - any allocation - at any power level. Setting a relatively low power level is the only way to placate countries who are worried about interference. Once there has been operation at low power with no interference, power levels can be increased. This is exactly what has happened in our experimental programs.
Re: 472 Kc Amatuer Allocation
Posted by John Davis on February 07, 2012 at 07:41:51.
In reply to Re: 472 Kc Amatuer Allocation posted by Frtiz Raab on February 07, 2012
Quite right. The allocation's the primary thing right now. And I can't imagine serious experimenters are going to be deterred by whatever power level comes out of it.
John
Re: 472 Kc Amatuer Allocation
Posted by Doug Williams - KB4OER on February 07, 2012 at 12:06:26.
In reply to Re: 472 Kc Amatuer Allocation posted by John Davis on February 06, 2012
Some people would complain if they had a tasting job in a pie factory.
While I have long hoped for a lower frequency allocation of around 137 kHz, I am happy to hear this allocation is moving forward.
Re: 472 Kc Amatuer Allocation
Posted by Lee on February 08, 2012 at 06:56:42.
In reply to Re: 472 Kc Amatuer Allocation posted by John Davis on February 07, 2012
Getting an allocation would be awsome. I'm a pretty good tech, but down here I do consider myself an "Experimenter" I would be ebullient If there was a 1 watt ERP allocation at LF.
Lee
Monday HiFERs in SE Kansas
Posted by John Davis on February 08, 2012 at 17:44:06.
Been so busy with further improvements to my ground system over the past two days, I forgot to report on Monday afternoon's HiFER DXpedition in the wheat field.
On Argo, all the usual suspecsts were present, nice and clear: MP, SIW, NC, USC, and COM. At times, SIW and USC were both audible as well.
Copied by ear: EH, GNK, and partial copy of FRC. I heard what I think were partial IDs from MTI and SZK, but I couldn't testify to it in court. AJO was not audible, but keying sidebands and the dash were visible on Argo.
John
New Clifton Labs Antenna
Posted by Pat Bunn on February 09, 2012 at 01:21:54.
I just got my Clifton Labs active antenna going and boy am I impressed. Used 300 feet of quad shielded RG6 run to the antenna which is mounted right at the edge of a pond. This gets it away at least 300 feet from any house in the neighborhood and also gives it a good ground. I have a Clifton Labs design common mode choke about 25 feet from the antenna with the coax grounded at the choke and another choke at he receiver. The receiver is a R75 with a good 7 pole filter in front of it.
Tonight, as an example I three European LW stations loud enough to easily hear the programming. The French station was very clear. Before, on the 80 meter dipole I could barely hear the carrier.
I was using the R75 with no converter. I am working on an AMRAD based upconverter with a Fox TCXO and hopefully will get it up and going this weekend. The older SBL-3 upconverter needs some work as I have something taking off and generating strong trash down at the very low end. The trash gets louder when the input coax shield is touched with no antenna connected. Above 80 Khz the converter works much better tha the R75. There is only a 7 pole LP filter ahead of the mixer.
Re: New Clifton Labs Antenna
Posted by Scott on February 10, 2012 at 03:34:02.
In reply to New Clifton Labs Antenna posted by Pat Bunn on February 09, 2012
Pat,
Where are you located?
Scott Re: New Clifton Labs Antenna
Michigan
Posted by Pat Bunn on February 10, 2012 at 13:45:37.
In reply to Re: New Clifton Labs Antenna posted by Scott on February 10, 2012
Spartanburg, SC EM98bw
RE: 160 m QRSS from Edmonds,Wa
Posted by Rick on February 10, 2012 at 19:27:45.
Hi to the group --
I have recently put a QRSS-10 beacon on the air on 1.855900, 100 milliwatts, with a 20m long antenna. All reports are appreciated.
Secondly, I am looking for a crystal that will go to 1.99xx to 2000Kc so that I can move it. If you have one in your junk box that you can part with please let me know --
Thanks -- Rick NU7Z
Re: RE: 160 m QRSS from Edmonds,Wa
Posted by Matt Burns on February 10, 2012 at 20:49:11.
In reply to RE: 160 m QRSS from Edmonds,Wa posted by Rick on February 10, 2012
Hi Rick,
If you can't find a rock in the 1.99 MHz range I have a LOT of 6 MHz crystals and some 74hc4017's that will work as dividers so you could divide by 3 to get 2 MHz then pull the crystal down to 5.990 MHz with a series inductor to get 1.9966 MHz.
I also have several thousand 13.500 MHz crystals that could be divided by 7 to get about 1.9286 MHz.
Let me know if you're interested and I'll send the parts your way.
Matt Burns Re: New Clifton Labs Antenna
kc8com
Posted by Doug Williams KB4OER on February 11, 2012 at 13:17:14.
In reply to New Clifton Labs Antenna posted by Pat Bunn on February 09, 2012
Pat I'm glad to hear things are working out for you with your new antenna. I agree with you wholeheartidly about the quality of the Clifton Labs antenna. I have had great success with mine this season.
I am also a firm believer that a good, stable upconverter in front of the R75 (or really, most any decent tabletop HF receiver) is a big improvement over trying to use the receiver directly on LF. There are very few receivers that have decent specifications on LF/VLF. The only receiver I have ever owned that I would consider a good LF/VLF receiver (without using a converter)was an AOR 7030, and it had the disadvantage of not having a 1Hz frequency readout or tuning step.
Now, the world of SDRs (software defined receivers) may be a whole different kettle of fish. Both the SDR-IQ and the Excalibur (or Excalibur Pro) may very will make great LF/VLF receivers out-of-the-box. I have no experience with SDRs as of yet.
Re: New Clifton Labs Antenna
Posted by Pat Bunn N4LTA on February 11, 2012 at 14:56:00.
In reply to Re: New Clifton Labs Antenna posted by Doug Williams KB4OER on February 11, 2012
Yes - I hope to get my new upconverter working this weekend. I am on board version #3. The TCXO is surface mount and I have screwed up th board twice. So this is version three and I still have some untested things to test(and hopefully not have a version 4 or higher) The front end filter and detector is the same as the AMRAD board. i am using a 16Mhx TCXO and am dividing by four and the TCXO is a clipped sine wave output so we will have to deal with that also.
The SDRs are a different animal and I am not quite ready to jump in. They do lots well but some things still bother me. I have a PC Board ready for a softrock board for HIGHFERs and have the right crystal but have not finished it yet. Too much to do!
Pat
Re: New Clifton Labs Antenna
Posted by John Davis on February 11, 2012 at 20:06:27.
In reply to Re: New Clifton Labs Antenna posted by Pat Bunn N4LTA on February 11, 2012
For my part, I still like a good analog receiver--ideally, one with all its local oscillators referenced to one master source. It saves a lot of frequency error headache over upconversion.
Granted, most general coverage radios treat the LF and VLF spectrum as afterthoughts, but if you provide them with sufficient signal, internal spurs and phase noise may be irrelevant. And if you include a modicum of low pass filtering, spurs from external out-of-band signals become immaterial, too. Doing this with an existing conventional antenna and a simple buffer amplifier can also be far cheaper than an active whip.
Whips are not magic! The big reason most contemporary receivers don't perform very well with everyday wire antennas is simply because of the nearly astronomical impedance mismatch between the antenna and the receiver input at low frequencies. What the receiver sees will be 50, 60 or more dB down from the open-circuit voltage the antenna is actually intercepting.
An active whip transforms the hi-Z of a very short (maybe a couple of meters long, maybe far less than 1 m) antenna to the vicinity of 50 ohms, where the receiver can then recover a good percentage of the terminal voltage of that antenna. That will generally be quite a bit more signal than a badly mismatched conventional antenna can deliver.
But why stop there? Why not let the receiver recover a good percentage of the terminal voltage of a full-size antenna? Then you can overcome most radios' LF shortcomings very easily. That's what my buffer amp project was designed to do... and apparently does, according to Rick KA2PBO. He still uses a loop antenna for situations where directionality is an advantage, but he told me "the buffer amp and my 50-ft 'T' wire have replaced my AMRAD (whip) antenna from now on."
(For sake of full disclosure, there is sometimes one legitimate answer to the "why not" semi-rhetorical question above. That reason is "risk of overload by singals above 500 khz." The solution, of course, is low-pass filtering in the buffer. Let's face it, LF is a special case for most radios, even many SDRs, so we might as well just get used to it. If you use an active whip because of its all-band capabilities, but still have to pre-filter and upconvert and maybe amplify a bit further ahead of your receiver in order to use it on LF and VLF, that's not much different from simply dedicating a conventional antenna and VLF/LF buffer amp for the same purpose...apart from the lower cost of the latter approach.)
Now, let me emphasize that I'm not putting down the Clifton Labs antenna in any way! I truly admire the elegance of its design. John Reed's previously published LOWDOWN test results clearly show it to be the best of the commercially available compact antennas for the amateur community, and superior to most custom and homebrew designs as well. It's also a great bargain for what it does, and I plan to buy one for my mobile and even more remote listening efforts. What I'm saying is, however, that it or any whip is not the ideal tool for all purposes. Especially not permanent or semi-permanent installations.
Have you read online accounts of people finding they need to elevate their active whips to get enough signal? They usually attribute it to getting above the shielding of nearby trees, or some such. But the reality is not so much that they're avoiding electrostatic effects as it is the simple fact that the whip forms an off-center vertical dipole, with the mounting pole and/or coax shield as the other side of the unintentional dipole. (See Andy Talbot's recent article on this subject in The LOWDOWN.) That's the same reason you often have to break up the coaxial run with isolation measures to prevent interference pickup from local sources. If active antennas were really true "e-field probes," the way they are so commonly misnamed, that would never be necessary.
Logical conclusion: for fixed use, one might as well set that "mounting pole" on an insulator and couple to it at the base with a suitable buffer. It's electrically the same, so far as radio waves are concerned, but it's physically easier to get to the amp if repairs are ever required. And if the spot is quiet enough electrically for a whip on a pole, it may be quiet enough for an even taller antenna, too.
Does anyone really need more signal from a taller antenna than a typical active whip provides? Yes, sometimes. When I built the buffer prototype late last summer and saw how dramatically it brought up both signal and noise, I seriously wondered if I could have settled for far less than unity gain from the buffer--as many whip antennas actually do, according to Steve Ratzlaff. Well, this winter there have been a few miraculous nights quiet enough in terms of both QRM and QRN that the limiting factor in my transatlantic reception was the internal noise of the receiver! A few more dB of antenna gain might have made the difference between missing a letter or two from MØBMU and G3KEV as I actually received them, and getting the complete, solid copy I would have preferred. As with many things in life, receive antenna efficiency is one of those things it's better to have available even when not needed, than to suddenly need and not have available.
Just some thoughts...
John
Re: antennas and receivers for LF
Posted by Doug Williams KB4OER on February 11, 2012 at 21:25:09.
In reply to Re: New Clifton Labs Antenna posted by John Davis on February 11, 2012
Well, John (who I have a great deal of respect for) has made, as usual, some good points.
Any active, e-field "probe" type antenna is going to be a compromise over a properly matched, full size antenna for the frequency of interest (in our case, VLF/LF).
Pat, let me assure you, however, based on my experience, that you have one of the best VLF/LF receive antennas available. From what you have described about your receive setup and location, I expect excellent results from your setup.
Ralph Burhans was the original (to my knowledge) proponent of active whip type antennas for VLF/LF reception, and I can send you a copy of his original articles, if you want. Most (99%) of us are forced to make many compromises when it comes to VLF/LF reception.
I absolutely agree with John on one thing....I like a good analog receiver. Perhaps I'm just not adapting to the current technology. Domo Arigato, Mr. Roboto.
KB4OER
Re: antennas and receivers for LF
Posted by Pat Bunn on February 11, 2012 at 23:46:42.
In reply to Re: antennas and receivers for LF posted by Doug Williams KB4OER on February 11, 2012
There are lots of parameters that make a good LF antenna. My 80 meter dipole is 70 feet high above the house and did a fair job, especially after I installed good common mode chokes and got rid of a lot of common mode noise.
This afternoon I sat down at the R75 and listened for about an hour with the new antenna. I heard about 45 NDBs - all were somewaht local - none more than 500 miles away but many that I had never heard - several in coastal Virginia. It was the basic R75 with a 7 pole filter ahead of it. The antenna overloaded the receiver with 4 or 5 local NDBs. The R75 is not a real good receiver in my opinion especially with respect to front end IMD.
I also heard several 500kc.com beacons loudly and the carriers from European LW station but not near as loud as earlier this week.
The main reason that I like this antenna is that it is 300 or more feet from the house with the mast in a lake edge with an excellent ground and located away from the neighborhood emi.
I am a fan of analog receivers also but getting one with a stable VFO is a tough problem.
I believe that with a good stable upconverter and my K3 as an IF - I will have a pretty good setup.
The upconverter testing had problems as the TCXO output a low level semi sine wave that will require a level converter. I remade the board and will have to wait until Tuesday to get a SM 74HC single inverter from Newark. It is a SM SOT package that is tiny but it fits and should do the job. Now I have to get the SM TCXO off the existing board without ruining the $25 part.
Pat
Re: antennas and receivers for LF
Posted by Doug Williams KB4OER on February 12, 2012 at 02:01:01.
In reply to Re: antennas and receivers for LF posted by Pat Bunn on February 11, 2012
"I believe that with a good stable upconverter and my K3 as an IF - I will have a pretty good setup."
I would have to agree. Except, from what I have read about the K3's receiver, I believe that will be an exceptionally good setup. ;-)
ur buffer circuit
Posted by Neil on February 12, 2012 at 03:43:44.
In reply to Re: New Clifton Labs Antenna posted by John Davis on February 11, 2012
John, can I get a diagram of ur buffer circuit that you talked about in one of ur posts? Your discussion was very interesting about LF receivers, up converters, "e-probes", etc.
Re: antennas and receivers for LF
Posted by John Davis on February 12, 2012 at 05:38:47.
In reply to Re: antennas and receivers for LF posted by Pat Bunn on February 11, 2012
>>>I am a fan of analog receivers also but getting one with a stable VFO is a tough problem.
True. And I suppose it's worth making a distinction that I overlooked when speaking of "analog" receivers, since it seems there are no contemporary receivers without a microprocessor or a PLL involving digital dividers somewhere inside them. "Analog receiver" is a term that nowadays might be understood to include a lot of digital circuitry everywhere but in the actual signal path...and it's getting harder to find all-analog there, what with all the DSP being added to "conventional" radios now. And there are real benefits to that DSP in many cases, although it also has unexpected drawbacks too. (Especially AGC related artifacts, per Rob Sherwood's presentation at the Dayton Drake Forum a few years ago.)
I agree with Doug that you have the makings of an excellent receiving setup there, Pat. Just from what I have read of the K3's specs, its noise floor is down there with the best contemporary gear, although none of them come close to the old Collins 75-3 with its -146 dBm. But the K3 beats even the Collins hands-down for dynamic range, for both near and far-spaced signals. Since one can always get more signal into a radio if necessary, dynamic range is probably far more important than noise floor these days.
I will continue to follow with interest your progress on the upconverter, as there are plenty of situations where that is the best approach. And I'll be interested in what you find while experimenting with the VFO you mentioned earlier. I'm intrigued by the VFO, although skeptical of phase noise performance at low frequencies. As with all microprocessor controlled devices, it may be a challenge to keep noise out of the receiver.
John
Re: ur buffer circuit
Posted by John Davis on February 12, 2012 at 05:43:45.
In reply to ur buffer circuit posted by Neil on February 12, 2012
>>>John, can I get a diagram of ur buffer circuit....
Surely. I'm presently merging the material presented thus far into a single article, and I will post a link to it this coming week.
It's nothing fancy, but I just want to make sure I haven't omitted anything or confused any points in the text.
John Re: New Clifton Labs Antenna
Posted by Doug Williams KB4OER on February 12, 2012 at 12:57:15.
In reply to Re: New Clifton Labs Antenna posted by John Davis on February 11, 2012
One point I forgot to make yesterday, is that compact e-probe type antennas do have one advantage over even properly matched large antennas at VLF/LF, even for permanent installations. If you are trying to receive LF from a less than ideal location in regards to local QRM (possibly generated in your own house), it is far easier to find a more QRM free location to place the e-probe than it is for a larger antenna, depending of course, on the size of your property.
But yes, if I had a QRM free property, I would get as much wire up in the air as I could for LF reception, then either match it with John's buffer amp or the passive antenna tuner that I built years ago based on a Burhans article.
Re: ur buffer circuit
Posted by Pat Bunn on February 12, 2012 at 14:52:48.
In reply to Re: ur buffer circuit posted by John Davis on February 12, 2012
John,
I made a PC board for your buffer circuit and I made an extra one for you if you want it. Nothing fancy and I made a slight error that was corrected with a resist pin before etching. I fixed it on the layout and was going to make you a clean new one but haven't had time.
Pat
Re: New Clifton Labs Antenna
Posted by Pat Bunn on February 12, 2012 at 15:04:52.
In reply to Re: New Clifton Labs Antenna posted by Doug Williams KB4OER on February 12, 2012
Wow,
I think I am realy getting the bug. Last night from 9 pm to 10 pm I played around with the new setup and was just amazed. My previous LW experience was tuning the ham receiver down and listening to the noise and hash and thinking there is nothing interesting here.
First, the European stations were S7 and if I understood Fench or whatever they speak in Algeria, I could have enjoyed the programming. I was not aware that they ever came in that loud.
Second the NDBs were piling in on top of each other and I copied two Canadian NDBs, one in the Bahamas, one in NY and 3 in Ohio just as a sample. Argo really helped as many DX NDBs were right on top of the locals. I really didn;t have time to spend pulling a lot of them out. I logged over 70 NDBs yesterday - many locals out 100 miles or so that I have never heard.
I logged three 500 KC.com stations and one Opera station at 500 Khz and heard the end of a qso between two 500 kc.com stations.
Lots of things to do. I'd love to get that 1 watt erp ham band .
Pat
N4LTA
Re: New Clifton Labs Antenna
Posted by Doug Williams KB4OER on February 12, 2012 at 15:26:34.
In reply to Re: New Clifton Labs Antenna posted by Pat Bunn on February 12, 2012
Excellent work! Now snag some Lowfers. Tonight tune to 185.300 kHz (don't worry about the converter, just use the R75 barefoot, with the LPF in front. Set Argo to QRSS30 slow, and see what you get.
Here is a sample:
http://dl.dropbox.com/u/33457409/185300Hz.jpg
And here is one with SIW also:
http://dl.dropbox.com/u/33457409/185300Hz%283%29.jpg
Re: New Clifton Labs Antenna
Posted by Pat Bunn on February 12, 2012 at 15:55:07.
In reply to Re: New Clifton Labs Antenna posted by Doug Williams KB4OER on February 12, 2012
Thats with the R75 on CW? with CW reverse?
I have not figured out Argo with respect to measuring the exact signal frequency. I need to get it properly calibrated
Pat
Re: New Clifton Labs Antenna
Posted by John Davis on February 12, 2012 at 18:04:48.
In reply to Re: New Clifton Labs Antenna posted by Doug Williams KB4OER on February 12, 2012
>>>If you are trying to receive LF from a less than ideal location in regards to local QRM (possibly generated in your own house), it is far easier to find a more QRM free location to place the e-probe than it is for a larger antenna, depending of course, on the size of your property.
Also, depending on the type of antenna. One with a large horizontal run will be harder to find a noise-free location for than a simple vertical pole, which is what the typical active whip is equivalent to.
One of those ubiquitous 43-ft super light one-man-assembly free standing poles, combined with a simple buffer, looks like a very attractive way to "super size" an active whip, in fact. That's what I plan to do in the opposite corner of my antenna farm once the LowFER rig occupies significantly more of my present antenna's time.
(That, alas, won't happen until I can find a way to make my "stealth loading coil" more efficient, or else make a full size loading coil much more secure in my absence. Until then, I can only operate when weather conditions allow me to be physically present, which just happens also to be the times I want to listen! Catch 22 and a half!)
That, in turn, brings up another thought regarding when a small active whip might be a better choice: when a full size antenna would cause neighbor objections. I recall that being Bill Bowers' recourse when they moved into their present neighborhood. :)
John
Re: New Clifton Labs Antenna
Posted by Doug Williams KB4OER on February 12, 2012 at 19:28:30.
In reply to Re: New Clifton Labs Antenna posted by Pat Bunn on February 12, 2012
"Thats with the R75 on CW? with CW reverse?
I have not figured out Argo with respect to measuring the exact signal frequency. I need to get it properly calibrated
Pat"
Pat,
Yep, put the R75 in CW mode and set it to Reverse, that way higher frequency signals will show up higher on Argo's screen. I also set the AGC to Fast.
The way I calibrate Argo for QRSS work is to tune to WWVB on 60kHz. You will probably need to turn the audio gain way down on the R75 because WWVB's signal is very strong in the U.S. Now set Argo so the center frequency displayed on the screen is the same as whatever BFO pitch you have the R75 set on (in my case 700Hz). Make sure the R75 has warmed up for 20-30 minutes before you calibrate Argo. Now start out by setting Argo on QRSS3 ("normal" speed). You will see a thick horizontal like start to scroll across the screen, and other thinner lines at 1Hz intervals above and below the thick like. You want the thick line centered right on your center frequency (whatever your BFO pitch is). If it is a bit off, which it almost certainly will be (mine is pretty consistently off by about 7 Hz), you go into Argo's "Calibration" menu. Here you will see an entry that says "measured frequency" set this to whatever your BFO pitch is. Then you will see a box that says "displayed frequency" set this to whatever frequency you see the thick line on the Argo screen. Once you get it dead on, switch to QRSS10 and do it again, but this time you will be making finer adjustements. Then skip to QRSS30 and you will be making very fine adjustments to the right of the decimal point. Once you get it dead on on QRSS30, that will be good enough for 99% of any LF QRSS work you will encounter, but you can go ahead and get it dead on all the way to QRSS120, if you want. If there is any drift in your receive system, you will see it.
This is just a basic calibration. Some operators prefer to have the actual frequency they are receiving displayed on the Argo frequency scale, but this necessitates making data entries into the calibration routine every time you change frequency, which, in my case, is often enough to make it a pain, so I just leave mine set to display my BFO frequency.
Clear as mud?
Re: "super size" active whip
Posted by Doug Williams KB4OER on February 12, 2012 at 19:51:44.
In reply to Re: New Clifton Labs Antenna posted by John Davis on February 12, 2012
That is a good point, John. Lately, and especially since the sunspot cycle is on the upswing, I have been getting the bug to get back into more mainstream amateur radio, and looking for an excuse to purchase a K3. I long ago took down my old 260' dipole that I used as a multiband antenna. I've been noticing the latest rage in HF antennas seem to be those 43' telescoping poles used as multiband verticals with an antenna tuner. Like you said, no reason that same 43' vertical, if properly insulated from ground, wouldn't make a good LF receive antenna with your buffer amp.
Re: Common Mode Chokes
Posted by Doug Williams KB4OER on February 12, 2012 at 22:38:50.
In reply to New Clifton Labs Antenna posted by Pat Bunn on February 09, 2012
"I have a Clifton Labs design common mode choke about 25 feet from the antenna with the coax grounded at the choke."
Well, I believe that is a very good idea. BUT....I hope you kept this common mode choke above ground. Because, as John has told me recently, it is virtually impossible to completely waterproof a buried common mode choke that incorporates any sort of supposedly sealed tube with any sort of coaxial connectors. Moisture WILL find a way to seep into any buried junction and eventually (a year or two) corrode the coax shield.
Final verdict: Keep any sort of junction above ground, and waterproof like you were preparing for Noah's Flood.
Re: Common Mode Chokes
Posted by Pat Bunn on February 12, 2012 at 23:18:19.
In reply to Re: Common Mode Chokes posted by Doug Williams KB4OER on February 12, 2012
Yes
The choke is in a plastic 4 x 4 gasketed box mounted on a piece of 1" rigid conduit 2 feet in the ground in concrete.
I mounted a 4" x 3/8" x 12" piece of aluminum plate on the conduit with clamps and the box is mounted on the plate with a type F grounding lug. Beside the pipe I drove a 8' ground rod and tied it to the ground lug with #10 bare copper.
The lead from the antenna runs to the type F ground lug, from there to the choke, from the choke back to the house to the next choke.
On another matter - the R75 set up with ARGO
When I receive, say a 100 Khz signal with Argo - and the R75 is set on 100 Khz - should the line in Argo be at zero or at the BFO tone (mine is set at 700 hz)
Pat
Re: Common Mode Chokes
Posted by John Davis on February 13, 2012 at 00:58:31.
In reply to Re: Common Mode Chokes posted by Pat Bunn on February 12, 2012
Many of us center Argo on the BFO tone...although as you may have seen in various captures, there are folks who set Argo to display the BFO tone as if it were the actual tuned frequency [ie, 137,780 for the 2200 m watering hole] if they're going to be settled on that one spot for the entire night. Personally, I always leave it at 800 Hz (Kenwood's default BFO note) and just state what frequency the radio is tuned to as equalling 800 Hz.
John
Re: Argo calibration
Posted by Doug Williams KB4OER on February 13, 2012 at 01:58:32.
In reply to Re: Common Mode Chokes posted by Pat Bunn on February 12, 2012
Hey Pat. Like I hopefully described earlier, you want to center the Argo display on your receiver's BFO tone (in your case, and mine, 700Hz). You fiddle with numbers in Argo's calibration screen until your calibration standard (I use WWVB) is at exactly 700 Hz on the ARGO screen.
Re: Argo calibration
Posted by pat bunn on February 13, 2012 at 02:09:35.
In reply to Re: Argo calibration posted by Doug Williams KB4OER on February 13, 2012
OK - Makes sense now - when you receive a signal at x frequency and the dial is set for x - then the receiver should generate a 700 Hz tone.
Thanks
Pat
Re: "super size" active whip
Posted by John Davis on February 13, 2012 at 06:55:59.
In reply to Re: "super size" active whip posted by Doug Williams KB4OER on February 12, 2012
I hope I can find a complete and nicely illustrated set of assembly instructions online for one of those 43-ft "maxi whips." That would help me determine whether it's realistic for me to think I can put one up single-handedly. (And I mean that single-handed business more literally than usual, having done something unpleasant to my right arm today, while unloading rocks to make a walkway to the existing antenna down there on Rancho Lodoso. If I'm going to incapacitate one hand or the other, it always seems to happen right when I need to be working on LOWDOWN columns and such.) If it looks practical for someone as uncoordinated as I am, then that will be on the budget wish list in the very near future. When not in use for listening, it might also serve as a HiFER antenna this summer.
John
Re: Argo calibration
Posted by Doug Williams KB4OER on February 13, 2012 at 10:34:10.
In reply to Re: Argo calibration posted by pat bunn on February 13, 2012
Hey Pat, I posted detailed instructions yesterday morning, but this thread has gotten so convuluted that you may have missed it. Here is the direct link:
http://www.lwca.org/mb/msg/2546.htm
Re: "super size" active whip
Posted by Pat Bunn on February 13, 2012 at 17:45:56.
In reply to Re: "super size" active whip posted by John Davis on February 13, 2012
John,
I bought individual 6" slotted pieces from DX Engineering and made a insulator out of Delrin sheet for my vertical. It was not hard to stand it up myself. I put in 64 radials myself also.
I just bought anothe 40 feet of tubing from them for a LF transmitting antenna.
Pat
Re: "super size" 43' fiberglass active whip hoisting mate
Posted by Lee on February 14, 2012 at 01:11:13.
In reply to Re: "super size" active whip posted by John Davis on February 13, 2012
JAM is using a 43' telescoping mast which I had to erect myself. Every one I knew suddenly had somthing else to do. The solution was a Harbor Freight 1500lb hand crank wench with BRAKE. BRAKE being the key word . Mounted on the top of a 12' 4x4 it was the high point I used to haul up the mast with guy ropes and internal copper pipe/radiator. having a brake lets you walk away to make adjustments, grab a beverage, check your smart phone etc. Always wear a hard hat! SJ off for season
Lee
Posted by Sal, K1RGO on February 14, 2012 at 16:16:10.
Well it looks like activity is down on lowfer band ,here anyway, plus the high noise floor hasn't helped so I am shutting down lowfer SJ and will be on by request until next season. Meanwhile the EH hifer and medfer continue to run as usual. Re: SJ off for season
later.........Sal, K1RGO
Posted by Doug Williams KB4OER on February 14, 2012 at 22:10:29.
In reply to SJ off for season posted by Sal, K1RGO on February 14, 2012
Sorry to see you go, Sal, but glad I was able to copy your Lowfer beacon this season. Do you reply to QSLs? I am WAY behind on my QSL cards.
Re: Common Mode Chokes
Posted by Doug Williams KB4OER on February 14, 2012 at 22:32:35.
In reply to Re: Common Mode Chokes posted by Pat Bunn on February 12, 2012
Well, your installation sounds ideal.
How did you like working with that "quad shielded RG6"? I've heard it is a nighmare. I opted for direct bury grade 50 ohm "mini 8" for my install. No real reason, other than my OCD, and I would have saved money by going for the 75 ohm direct bury RG6.
I finally got my common mode choke installed today inside the shack (between the DC power coupler and the antenna). I would like to install another one (with the coax shield grounded) at the base of my antenna. I should use your installation as a guide on how to do it correctly. Guess I'll be placing another digikey order. I also installed several toroid chokes on the DC power leads of most of my shack accessories.
Re: 472 Kc Amatuer Allocation
Posted by John Davis on February 14, 2012 at 22:59:09.
In reply to Re: 472 Kc Amatuer Allocation posted by Lee on February 08, 2012
http://www.arrl.org/news/amateur-radio-gets-secondary-mf-allocation-at-wrc-12
Big step forward today! In about a year, there could be regular licensed ham activity in the new band...at up to 5 W EIRP in areas located 800 km (~ 500 miles) from non-participating nations.
Re: Common Mode Chokes
Posted by Pat Bunn on February 15, 2012 at 00:17:37.
In reply to Re: Common Mode Chokes posted by Doug Williams KB4OER on February 14, 2012
I am doing the same with the power in my shack plus the computer network cable. My noise is down considerably. I used the 2.4" type 31 material.
The quad wasn't so bad. I broke down and bought a Burndy install tool and it made the snap and seal connectors easy to install.
COM off air yesterday and today
Posted by Matt Burns on February 15, 2012 at 11:53:30.
Hifer COM will was off yesterday and will be off today until I get time to make some adjustments. I made a slight overestimation of the vertical bandwidth of my scope so after checking on a newer 40 MHz scope I should be able to get the power level set to a more precise 2.5 mw.
73's,
Matt Burns USC Antenna
kc8com
Posted by Pat Bunn N4LTA on February 15, 2012 at 16:44:11.
The USC antenna was knocked over by high winds last weekend. I did not notice it until yesterday and will repair it in the next few days. It is still transmitting but likely not effectively.
Pat
Re: USC Antenna
Posted by Doug Williams KB4OER on February 15, 2012 at 22:15:53.
In reply to USC Antenna posted by Pat Bunn N4LTA on February 15, 2012
"USC", as in Univeristy of South Carolina?
I'm sorry, I didn't hear you over the sound of the fans of the University of Tennessee.
Sorry your USC antenna got blown down. Perhaps you should relocate it to Tennessee? ;-)
Re: USC Antenna
D.
Posted by Pat Bunn on February 16, 2012 at 00:19:39.
In reply to Re: USC Antenna posted by Doug Williams KB4OER on February 15, 2012
Nah - as in Upstate South Carolina
I'm a NCSU graduate - BSEE long, long ago........1973 is a long time ago.
My daughter is a University of SC grad - My youngest son is at at Clemson - My oldest is a Georgia Southern grad
10 years so far of writing big checks - only 4 more to write - I hope!
Pat
Re: 472 Kc Amatuer Allocation
Posted by Neil on February 16, 2012 at 00:57:31.
In reply to Re: 472 Kc Amatuer Allocation posted by John Davis on February 14, 2012
Now we need to have pressure put on the FCC to make it available to US Hams. It never did happen for 136 khz probably because the FCC did not think enough people cared. Just my opinion....
Re: 472 Kc Amatuer Allocation
Posted by Pat Bunn on February 16, 2012 at 01:40:35.
In reply to Re: 472 Kc Amatuer Allocation posted by Neil on February 16, 2012
It was the power companies that prevented the 136 Khz band from happening. I think the 472 - 477 Khz band is likely to happen and at the 5 EIRP level. I have not heard of any other interest that are opposed to an amateur band at those frequencies.
I am starting design work on my 500 watt class D transmitter now!
Pat Re: USC Antenna
N4LTA
Posted by Doug Williams on February 16, 2012 at 12:49:31.
In reply to Re: USC Antenna posted by Pat Bunn on February 16, 2012
Nice! Sounds like you raised good kids.
My wife and I never had any, so I'll be all alone when I go to the nursing home. Or....I might be "that crazy old coot who lives up on the hill with all the antennas. Stay away from him...he's strange."
COM on air ~13557.888, power calculations
Posted by Matt Burns on February 16, 2012 at 12:58:19.
In reply to COM off air yesterday and today posted by Matt Burns on February 15, 2012
I made the needed changes to hifer COM and put it back in last night. Changing the supply voltage (and the resistance across my pseudo-varactor 1n4007 to maintain the 10 hz shift) seems to have shifted my frequency up a bit, I may try to pull it back down to where it was if time permits.
Just for a quick sanity check, the output into a 50 ohm load on the good scope shows 1vp-p so 1/2.828=0.3536 vrms then 0.3536V/50 ohms=0.00707A and 0.00707A*0.3536V=0.0025 watts=2.5mw
Thanks,
Matt Burns Re: SJ off for season
kc8com
Posted by Sal,K1RGO on February 16, 2012 at 17:32:11.
In reply to Re: SJ off for season posted by Doug Williams KB4OER on February 14, 2012
I can qsl, I can get address on qst website....if you want one , its my old ham qsl with a few sharpie mods... Re: SJ off for season
later
Posted by Doug Williams KB4OER on February 16, 2012 at 20:23:50.
In reply to Re: SJ off for season posted by Sal,K1RGO on February 16, 2012
That would be great Sal. I'll send you one also.
Here's the proof:
http://i81.photobucket.com/albums/j231/Goranothos/SJ-1.jpg
Looks like 12/27/2011 at 9:12PM EST. That was before I switched my PC over to UTC.
USC Antenna Back in Operation
Posted by Pat Bunn on February 18, 2012 at 18:21:00.
The USC HIFER antenna is back up and USC is back operating.
Any reports would be appreciated.
Pat Re: SJ off for season
N4LTA
Posted by Sal.K1RGO on February 19, 2012 at 22:39:15.
In reply to Re: SJ off for season posted by Doug Williams KB4OER on February 16, 2012
I just finished the QSL , will be in the mail Monday. Re: USC Antenna
later.......
Posted by John Davis on February 20, 2012 at 00:30:10.
In reply to Re: USC Antenna posted by Pat Bunn on February 16, 2012
The repair seems to be working well! Here's how it looked in Kansas this afternoon.
Re: USC Antenna
Posted by Pat Bunn on February 20, 2012 at 01:48:00.
In reply to Re: USC Antenna posted by John Davis on February 20, 2012
Thanks for the report John. Looks like it is working.
Pat
Hifers
Posted by Garry, K3SIW on February 22, 2012 at 14:03:22.
Shut down hifer SIW briefly around 1900Z 022112 to listen and copied the NC square waves on 13.555615 MHz (top tone), EH on CW at 13.557032 MHz, and USC on QRSS3 at 13.554018 kHz.
73, Garry, K3SIW, EN52ta, Elgin, IL
1110 khz station heard on 210 khz
Posted by Brinton Allison on February 23, 2012 at 02:03:38.
I don't know radio, but I just bought a Kaito KA1103 specifically to listen to long wave. I tuned in several East Coast commercial between 200khz and 300khz, and figured out that the stations were broadcasting on the long wave frequency indicated on the dial plus 900khz. For example, at 210khz I was receiving a station that said it was broadcasting on 1110khz: switching to 1110 AM I heard the same broadcast. I found about five stations that conformed to this pattern. Does this mean my Kaito KA1103 is defective, or is this behavior some property of LW/MW? Thank you. Brinton
Re: 1110 khz station heard on 210 khz
Posted by John Andrews on February 23, 2012 at 13:54:53.
In reply to 1110 khz station heard on 210 khz posted by Brinton Allison on February 23, 2012
Brinton,
The Kaito KA1103 is described as a dual-conversion receiver, with a 1st IF at 55.845 MHz and the 2nd IF at 450 kHz. This suggests the possibility that if it has a very wide bandwidth at the 55.845 MHz 1st IF, you may get "images" of signals that are 2 X 450 = 900 kHz higher in frequency than the desired signal in the second conversion. If so, then the only thing you could do (without modifying the radio) would be to use an external antenna for LF, with enough low-pass filtering to reject the strong AM broadcast signals.
More serious (expensive) radios would have enough selectivity in the 1st IF to greatly attenuate signals that far from the desired ones.
John Andrews
Re: 1110 khz station heard on 210 khz
Posted by Brinton Allison on February 24, 2012 at 00:48:59.
In reply to Re: 1110 khz station heard on 210 khz posted by John Andrews on February 23, 2012
John,
Thank you for the explanation, my question is answered.
Brinton.
Re: PLC Freqs Hunting
Posted by Steve on February 27, 2012 at 07:09:43.
In reply to Re: PLC Freqs Hunting posted by Lee on January 11, 2012
Hi...am new to this msg board...find it relevant and interesting...being plagued with an excessive amount of QRM
in the entire spectrum from approx 20 kHz to 400 kHz ++.
In my past experience with PLC's ....the scheme for signal
transmission is for a type of point to point type of comm. and not to be sent over great distances. Usually over a dedicated power line, one Rx/Tx, same frequency at both ends; usually from one Hv power Sub-station to a distant one. In order to prevent the signals from travelling beyond the intended sub-stations, a parallel tuned 'wave-trap'is installed at each end to block the signal from the line going beyond the intended sub-station. The signals should not propagate hundreds of miles beyond the intended sub-stations. However,radiation from the line between the sub-stations can take place all along the length of the line between the sub-stations. In some schemes, depending on the type of equipment used, will only transmit in the event of a problem on the particular line. Possibly,and depending on the the protective relaying scheme, employ a type of freq. shift keying and , therefore may xmt continuously. If i can locate a freq list, I'll post it.
Well, my 2 cent's worth
73...Steve
Re: PLC Freqs Hunting
Posted by John Davis on February 27, 2012 at 18:32:00.
In reply to Re: PLC Freqs Hunting posted by Steve on February 27, 2012
Thanks, Steve. Your observations (and any additional information you might uncover) are appreciated.
When you mention "However,radiation from the line between the sub-stations can take place all along the length of the line between the sub-stations," I believe that's what most of us are experiencing. Once radiated, the carrier can travel quite some distance, considering the stable propagation at LF and the high sensitivity of most of our receiving setups.
Some PLCs I detect at my location are constant in level, while others exhibit diurnal variations, indicating that they are arriving by skywave propagation. Those can travel very long distances indeed!
John
RMCA 8702-a Direction finder Schematic ?
Posted by Mark on February 27, 2012 at 23:42:28.
Subject says it all...I'm looking for the schematic or any info on a radiomarine AR 8702-A direction finder
Hifer COM qsy 13556.410
Posted by Matt Burns kc8com on February 28, 2012 at 12:03:16.
Hi All, I've moved COM down into a quieter portion of the band hopefully, the 66% duty cycle "rectangle wave" pattern remains the same except that the shift seems to be about 8 Hz now, the power is still 2.5 mw. I'll try to keep this frequency constant and leave the transmitter on regularly so give it a listen.
Thanks,
Matt Burns Help I.D. some Donuts
kc8com
Posted by Lee on February 29, 2012 at 01:05:00.
I found some Toroid ferrite material forms in my parts stash and thought I would play around with some balun designs. Any Idea what the color codes indicate. The larger form about 2.75 inch OD is grey in color. The smaller form about 1.5 inch OD is mostly yellow but has one side that is white. Thanks for any input.
Re: PLC Freqs Hunting
Posted by Steve on February 29, 2012 at 05:23:39.
In reply to Re: PLC Freqs Hunting posted by John Davis on February 27, 2012
Hi John...Tnx for replying...this is great..interchange and sharing of ideas and information. I don't claim to be an expert in the VLF & LF area of the hobby...trying to learn as much as possible; information doesn't seem to be readily available; seems that everything is a bit of a challenge, at least for me. It's been a while since i did any work in the PLC area and that was for a short time only. Will try to glean some info from guys who worked in it more than I; will post as it becomes available.
Would be interested in finding out what you're experiencing in your geographical area such as how many and at what operating frequencies, signal levels etc., of PLC's you've encountered ?
Usually i scan across the spectrum from about 20 to 500 kHz
with my NRD 535 Rx which is plagued with many birdies all over. Additionally,there are, what appear to be , solid carriers or local EMI from appliances,i think, making monitoring a real challenge.My antenna is a random , horizontal antenna in a loop like configuration around the perimeter of my lot ( approx 300 ft ) 10 to 15 ft above ground.
Last night i heard , what sounded like , Loran-C peaking at approx 03:30 UT, between 90-110 kHz ;peaking at S-7 on 115 kHz, am mode; lowest bw of rcvr is 2kHz...wonder if anyone else heard it ? I was under the impression that Loran was phased out. This was the first time i heard it since shut-down. Re: Help I.D. some Donuts
Tnx...Steve
Posted by Lee on February 29, 2012 at 05:48:04.
In reply to Help I.D. some Donuts posted by Lee on February 29, 2012
I think I have answered my own question. Found this
Iron Powder Material
Basic Iron Powder
Material Permeability µo
Temperature Stability (ppm/°C)
Resonant Circuit Frequency Range (MHz)
Color Code
0
Phenolic
1
0
100.0 - 300.0
Tan
1
Carbonyl C
20
280
0.5 - 5.0
Blue
2
Carbonyl E
10
95
2.0 - 30.0
Red
3
Carbonyl HP
35
370
0.05 - 0.5
Grey
6
Carbonyl SF
8
35
10.0 - 50.0
Yellow
7
Carbonyl TH
9
30
5.0 - 35.0
White
10
Carbonyl W
6
150
30.0 - 100.0
Black
12
Synthetic Oxide
4
170*
50.0 - 200.0
Green/White
15
Carbonyl GS6
25
190
0.10 - 2.0
Red/White
17
Carbonyl
4
50
50.00 - 200.0
Blue/Yellow
26
Special
75
882
LF filters, chokes
Yellow/White
Material #17 has been developed as a temperature stable alternative to the #12.
Frequency ranges shown are for best 'Q'/ Useful over broader frequency ranges with lower 'Q'.
Re: Help I.D. some Donuts
Posted by Pat Bunn on February 29, 2012 at 13:53:39.
In reply to Re: Help I.D. some Donuts posted by Lee on February 29, 2012
You probably have found the answer but before you spent a lot of time building these forms into a project, I'd verify the core type by making a coil and testing it. There is a lot of imported stuff out there that is not standard. Wind 15 turns or so on it and calculate the expected inductance value. Verify it with an inductance meter or put a capacitor in parallel with it and sweep it and measure the resonance frequency. You can also use a GDO with a one turn coupling loop.
Re: PLC Freqs Hunting
Posted by John Davis on February 29, 2012 at 19:17:30.
In reply to Re: PLC Freqs Hunting posted by Steve on February 29, 2012
I often encounter LORAN chatter at night on 100 kHz. This is from Western Europe, where the system is still used somewhat. Thank goodness it's no longer the bone-rattling racket of years gone by!
John
Re: Help I.D. some Donuts
Posted by Lee on February 29, 2012 at 20:33:15.
In reply to Re: Help I.D. some Donuts posted by Pat Bunn on February 29, 2012
Excellent tip. I have one of those new imported iductance meters being sold on ebay. Thanks..
Lee
potrzebie