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Author Topic: UNID carrier on 3885  (Read 6424 times)
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Tim WA1HnyLR
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« on: July 31, 2019, 11:23:22 AM »

For the last couple of days there has been an unmodulated carrier about 3885 creating a noticeable hetrodyne on received signals. In the day time I can detect it well with the  wire array. It is practically non- existant on my low 160meter dipole. Others can hear it as well. It is piss weak so it is not a big deal . For a moment I thought is was something local to me But i did witness QSB on the signal. I believe it is coming from western PA , NY , Ohio,or some other Midwest state Fact is there are modists that hate AM and will go to whatever lengths to increase the misery factor for us. I have seen this carrier or something like it in the past. Others begin to talk about it ,,,,after a while it goes away. When I am not crapstal controlled, I zero beat it. In the past number of years it seems that many people have lost the art of zero beating when the carriers dumpers show up Rather than piss and moan about the hetrodyne interference , just quietly zero beat the interferer and mention that a number of the others in the QSO must zero beat with out mentioning why, make up some excuse like" it good operating practice ,or I am using a receiver with a sync detector therefore you must all zero beat. Pay no attention to the man behind the curtain. The problem is old school VFOs that are in our treasured vintage transmitter drift. Frequency stability is a must .The best method of frequency control is a moderne rice box, An SDR,a DDS vfo or a VXO. A recent transmitter acquision of mine is a transmitter I built  some 50 years ago. I built a crude VXO circuit that works quite well. Unfortunately I have moved the transmitter into it's final operating position, but have not plumbed it into my station rats nest on interconnecting cables. I find the VXO particularly useful for 40 meter operation in zero beating annoying carriers from various shortwave broadcash stations. Here in the North East 7295 has an annoying weak carrier that comes in in the afternoon. 7290 is worse in the afternoon. The oriental wrecking ball comes along and cleans out 7285 in the afternoon. 7275 is a good place to be.
Well I guess I got on a rant here but I hope that itis an incentive to have extreme frequency stability when dealing with interference. One must always look before they leap. Always spot yourself before you transmit. So many times I hear these bleeding hetrodynes from not zero beating the interference. One more thing: Don't piss and moan about the fact that some dummy is Quirming the QSO. This just adds more credence the the miscreant involved.
De Tim WA1HnyLR
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WA2SQQ
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« Reply #1 on: July 31, 2019, 11:49:39 AM »

Some fairly accurate direction finding was demonstrated using the on line SDR receivers. I recall that someone had posted the instructions here, on this site, how to do this. Step one might be to check the various SDR receivers that are on line and see who hears it best, and noting the time of day. I have a similar situation for almost 3 years, with a signal that wanders from 3.870 to 3.888. I know it's local to me, but so far have not been able to determine what it is.
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W2JBL
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« Reply #2 on: July 31, 2019, 06:50:02 PM »

I'm hearing the carrier here at about S9 as I write this. Tim: very good point about zerobeating and VFO stability. How is it that many put so much work into "restoring boatanchors" and they never do anything with the VFO or PTO? I hear so many stations way off the frequency the QSO started on and nobody seems to vero beat anymore. There are two nets down south that cause a lot of trouble in the Norteast on 3885 who's members are spread out a good 1KC above and below 3885. Many of the op's rigs drift a full 1-2 KC in the intial keyup then settle down to a slower drift. Of course this happens on all bands and with many different ops. Makes it impossible to zero beat the distant QSO. There is no excuse for the kind of drift I hear on the bands. Some try to claim the rigs were never stable when new but that is simply not true. If they were that bad (I know they were not)they would not have been very useful on CW. My 32V2 is as stable as a ricebox, but there's a guy in W3 land with one that drifts 1KC per minute as he buzzards away... Time to break the seal and replace that 60 year old 6SJ7 OM.
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ka1tdq
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« Reply #3 on: August 02, 2019, 11:22:29 AM »

WA1FFL sells a kit to drive a tube rig with a DDS VFO:

http://wa1ffl.com/DeMaw_CQ91.pdf

I've used one of these to drive a DX-60 with success.  I've also used two on a class E rig to drive both phases.  You can kill DC power to the kit and keep the output of the DDS VFO going during receive.  This way you won't hear the carrier on your local receiver. I mention this because I use a Chinese DDS VFO and there's no simple way to kill the RF output during receive other than keystrokes.

Jon
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WBear2GCR
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« Reply #4 on: August 02, 2019, 11:35:47 AM »


Appears to have gone away now.

It was weak/inaudible to my ANT, while it was audible on the QIX SDR antenna... what does that mean?
Not much.

Jamie, N2VJ (new call) reports that he was mobile and it came up in level as he drove through State College PA,
but the band also was coming up at that time. Otoh, that nasty high level carrier on the same frequency
from some many months back now, WAS reportedly coming out the State College PA, in some lab. Although that
was not confirmed - it did suddenly stop once the FCC stepped in and reportedly made a few phone calls.

I'd vote for using the online SDF DF site IF it comes back on. That will give a very solid triangulated location.
The system is based on time of arrival and I think GPS clock coordination...

                          _-_-bear
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_-_- bear WB2GCR                   http://www.bearlabs.com
WA2SQQ
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« Reply #5 on: August 02, 2019, 06:26:43 PM »

Nice work!
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N1BCG
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« Reply #6 on: August 03, 2019, 11:08:06 AM »

Some fairly accurate direction finding was demonstrated using the on line SDR receivers. I recall that someone had posted the instructions here, on this site, how to do this.

Is this the thread you were thinking of? http://amfone.net/Amforum/index.php?topic=44439.msg319764#msg319764

The carrier was localised to Ontario to a QTH in Hamilton, Ontario by SDR and a friend who DFed this station. I will PM anyone interested in his identity etc. The carrier was on for almost 48hrs. BTW he is a wannabe AMer..lol.

I'm not really curious who it was, particularly if it was unintentional, but I am curious what it was and why it was on for 48 hours. I'm sorry I missed it. It would have been a fun DF...
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WA2SQQ
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« Reply #7 on: August 05, 2019, 09:02:57 AM »

No, this one
http://amfone.net/Amforum/index.php?topic=45036.0

https://www.rtl-sdr.com/kiwisdr-tdoa-direction-finding-now-freely-available-for-public-use/

There is a link that describes the entire TDOA procedure. Got a few more honey-do jobs to finish before I can sit down and play with his technology.
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ka8gef
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« Reply #8 on: August 05, 2019, 09:05:35 AM »

There has been a steady carrier over the last few days, perhaps longer, on or around 3879-3880kHz. It is 15db+ over S9 with very little QSB here in the Cleveland area. The signal is 20+ over S9 at the Kingsville Ontario web/SDR receiver west of Hamilton.

I don't know if the source is the same but it is clearly not some kind of harmonic etc.

If someone (i.e. VE3AJM etc.) would kindly e-mail me the info on the clown in Hamilton ONT....it would be most appreciated. He is just across Lake Erie from us. I don't know if he is the same QRM'r noted above but it would be good to know who he is...thanks. ka8gef

zelasko54@roadrunner.com

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KK4YY
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« Reply #9 on: August 05, 2019, 05:58:42 PM »

No, this one
http://amfone.net/Amforum/index.php?topic=45036.0

https://www.rtl-sdr.com/kiwisdr-tdoa-direction-finding-now-freely-available-for-public-use/

There is a link that describes the entire TDOA procedure. Got a few more honey-do jobs to finish before I can sit down and play with his technology.
Plan on spending some time DFing a stations of known locations. There's a learning curve involved to get good results. Practice.


Don
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W1RKW
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« Reply #10 on: August 05, 2019, 06:02:30 PM »

I heard the same last night for several hours on the bedside receiver from 8PM to 11PM DST. It was fairly steady here in central CT at about S7 give or take.

There has been a steady carrier over the last few days, perhaps longer, on or around 3879-3880kHz. It is 15db+ over S9 with very little QSB here in the Cleveland area. The signal is 20+ over S9 at the Kingsville Ontario web/SDR receiver west of Hamilton.

I don't know if the source is the same but it is clearly not some kind of harmonic etc.

If someone (i.e. VE3AJM etc.) would kindly e-mail me the info on the clown in Hamilton ONT....it would be most appreciated. He is just across Lake Erie from us. I don't know if he is the same QRM'r noted above but it would be good to know who he is...thanks. ka8gef

zelasko54@roadrunner.com


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Bob
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His fear was when I turned it on for the first time life on earth would come to a stand still.
N1BCG
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« Reply #11 on: August 05, 2019, 10:25:01 PM »

There was a lot to learn from DFing the State College signal last year. It’s not only important to choose receivers that are likely to be off widely varying radials from the suspected source (improves triangulation accuracy) but also to run several heat mappings to compare for the most consistent “hot areas” (where the signal is most likely originating). The ones that produce the most concentrated red areas are the most accurate.

Sky wave reflections create inaccuracies due to time delays, but the most useful heat maps were achieved early in the evening when noise was low and skip variations minimal.

https://forums.qrz.com/index.php?posts/4893891/

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ka8gef
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« Reply #12 on: August 06, 2019, 09:48:40 AM »


This process/system looks to be a fun project....but right now the guy is 20db over S9 on 3885 and wiping out the AM window here in the Cleveland area as he jumps between 3880/3885.

We just want him shut down.

Please advise his call/name etc. if anyone knows who he is (someone located him in Hamilton ON.). This is clearly intentional, he is not fixed on one frequency....

Thanks
ka8gef

zelasko54@roadrunner
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WA2SQQ
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« Reply #13 on: August 06, 2019, 10:31:01 AM »

While its annoying, it's a good signal source to practice some TDOA DF'ing !
Is the FCC's counterpart in Canada responsive to complaints?
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N1BCG
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« Reply #14 on: August 06, 2019, 10:41:40 AM »

Is the FCC's counterpart in Canada responsive to complaints?

Now that's funny. Industry Canada has shown little interest in enforcement, even when a formal request is made by the F.C.C. as was the case with Karol Madera http://www.ve7kfm.com (14.313 & 7.200).

The carrier is fairly strong on this SDR: http://w8hf.ddns.net:8073/?f=3890.00amz10

Unfortunately, it's not GPS/TDoA enabled. I tried it with six usable SDRs but there's a SSB QSO throwing off the results (too many locations).

VE3AJM seems to know who it is so that's where the mystery ends.
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ka8gef
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« Reply #15 on: August 06, 2019, 10:52:57 AM »

I sent Al an e-mail this morning....looking forward to hearing from him.

 

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