What is The strangest or hardest to find radio Qrm you've ever had.?

[AC4BB]

What would you say was the most unusual or hardest QRM to track down on your radio.? What it a Hairdryer from next door ?Neighbors Garage door or other.?

[NI7I]

What would you say was the most unusual or hardest QRM to track down on your radio.? What it a Hairdryer from next door ?Neighbors Garage door or other.?
Hairdryers are seldom sources of QRM.. Nor are garage doors. Think perhaps yyou missed by one letter in the ole alphabet..

NI7I

[A71AN]

What would you say was the most unusual or hardest QRM to track down on your radio.? What it a Hairdryer from next door ?Neighbors Garage door or other.?

What it a Hairdryer from next door ?Neighbors Garage door or other ?

This is not called in QRM, but QRN, noise created due to many sort of Interference, could be in your place or as you have stated coming from your area or or your Neighbors.

QRM is when Some one else transmitting on your frequency the same radio transmission as your.

Thank you my friend 73

[vk4agk]

Where do you posters get ideas? Do not read?

Qrn = n ,natural , noises converted
Qrm= m ,man made , noises converted

on frequency or wide band , ex cb'ers? , Lol

anyway , took me ages to find something (i think it was a digital clock)

the easiest way is turn off the main power into the house using a battery reciever , noise go away = in house...

but , another opposite to that is the/a noise comming down the line so even when the main power is off its still radiating (thats referenced to a mercury vapor light not arc-ing up, igniting? 500 meters away)..

[ka0gkt]

I remember a repeater in Omaha having problems with a noise source which was traced to a dead cockroach in a Smoke Detector at a Senior apartment complex.

Then there was the FM station which had problems and would get enough synchronous AM to be detected by the guitar amplifier of a musician a couple of blocks away from the transmitter site.

Then there was the lady who had an "illegal" (according to her HOA) retractable clothes line which she would reel out at night and hook to the back stay of a power pole with a caribbeaner. Enough RF was induced from a nearby 1-KW AM station to throw harmonics all over the place, but the problem was only at night.

Neighbor's Oil Burners.

Tropical Fish tank heaters,

Diesel exhaust blowing across the antenna (it is fairly ionized and makes a tremendous noise).

Corona discharge from the second anode supply in an old TV set.

Bat detector harmonics (Yeah, someone built a really high powered ultrasonic generator which threw squarewaves and had harmonic content into the 160 meter band...the dogs in the neighborhood would howl whenever this guy fired the thing up. I added an RF choke and a couple of bypass capacitors to the guys circuit and cleared up the problem...and, yes, the ultrasonic signal beat with the bat's echolocation and made it audible...kind of neat, really...but this guy's belfry was one or two bats short! :eek:

[KI6NNO]

My most difficult source of QRM to deal with seems to be my YL. The easiest to identify though... ;)

There's this freeway "Meter On" on-ramp sign at Lake and the I-210 that is amazingly splattery on 10M when it pulses on and of. I was having to run the squelch up on my radio in the area. It was kind of weird. Anyway, it took me a while to figure out what it was. It was eventually just a matter of taking that particular on-ramp when sign was flashing was on and I had one of those "aha!" lighbulb moments. You can hear it for over a mile. Does the city of Pasadena (CA) do anything about it, Nooooooo.... :mad:

[KE7OJQ]

My wife's sewing machine which ends up making a pulse that matches the speed it's running at.

[w8znx]

cooking doorbell transformer

[AC4BB]

Years ago when our 2 meter repeater was near a local cell tower and the weather was foggy or wet the strobe lights would sound like a machine gun on the repeater . When we moved the machine all that went away.

[N5USR]

Heh... I was! :p

Okay, not really - but I did wind up showing a bunch of people how tough it could really be to track down a signal...

We were doing foxhunts each weekend, we'd get a decent group of people together - maybe 15-20 each weekend - to do a "northside" and "southside" hunt on simplex. Problem was, everyone was getting too good at it - the hunts themselves would only last a half hour or so as everyone more or less drove right to the fox.

So a friend and I proposed a different style of hunt - countywide, on a repeater (the club had two VHF machines, so we would use one and they could coordinate on the other). They went for it, and my friend and I went looking for good hiding spots. The point of using the repeater was we wouldn't have to be audible from any particular starting point, they would have to FIND the signal first!

The first one of these we did, it took many hours for them to find us, and they really just stumbled across us - there was a ridge between us and the rest of the county, each time they approached the ridge the signal disappeared. Finally someone drove across the ridge - and wow! :) They also spent a fair amount of time chasing a false signal - one of them finally figured out that they were chasing an image, if I was talking on "my" repeater while they used the club's other one, a false image showed up very close to my input frequency - right at the repeater tower site!

The second one took TWO hunts! We went literally to the farthest end of the county from the repeaters (we were tricky - while we were still in the county, you had to drive OUT of it to get there, thanks to a river). The first day they hunted for hours and never got a trace of the signal. They even had people who didn't normally hunt sitting at home using their beams, a couple got access to the roof of a building downtown. But we were on a handheld, using 1/4w or less into the least efficient duck I could find, so the repeater at 1100 feet could hear us just fine but no one else did.

We had to give some clues the second time out, and they did finally get to us, but it was great fun (for us, anyway) listening to all the trouble they had! :D We even had a small audience at one point, some people who lived down the road we were sitting beside stopped to see what was up (I had a folding table and chairs set up this time, with all my other radios sitting on it tuned to every frequency they were using to coordinate) and got a kick out of listening to the hunt traffic too.

[k3wrv]

These are actually related, but let me pose two situations:

When I got High Speed internet, my noise level went up dramatically, but especially in the late afternoons, after work. Unplugging the FIOS equipment helped, but didn't cure it.

Even after unplugging the FIOS stuff, there was still more noise than I'd been used to, and it almost always peaked in the West in the late afternoon.

I assumed it was somebody in the mid west runing an ARC welder into a really good antenna of some sort, and it seems to be more horizontally than vertically polarized, and is much worse on the beam than on a dipole.

I don't have any close neighbors to the West - maybe a mile or so away, and most of them don't have ARC welders. My thought is that's part of the noise is from Solar origin. Anybody got a better idea? (Yep, I've driven around with the Car radio, a pportable, and even my QRP rig in the car, and still haven't found any likely prospects. The noise sounds like "hash". Pretty sure that fibre optic lines wouldn't radiate, but at the same time, Comcast installed Cable lines. But they're buried.

de Bob

[K9STH]

Years ago one of the local 2-meter repeaters was located at a hospital and started getting interference for several hours a day and the repeater technical committee could not locate the source. Finally, after several weeks of looking for the problem the head of the committee came by my office and asked for assistance.

I did a quick calculation and told him to go to the hospital parking lot and look for a particular model Motorola car telephone with a certain "home channel". When improperly aligned that model of radio would radiate the receiver injection frequency on the exact frequency of the repeater input. Within 15 minutes the head of the technical committee telephoned me to tell me that he had found the offending unit. It seems that a certain doctor had acquired a mobile telephone unit (this was before the days of cellular telephones) and that radio was radiating on the input frequency to the repeater. The car telephone was realigned and the problem "went away".

The same repeater also suffered problems on the output frequency (when received by amateur mobile units) when a particular taxi company's unit was within a couple of blocks. Although the taxi company's radios operated in the 450 MHz range the injection chain for the receiver had a very strong "spur" that was less than 2 kHz from the output frequency of the repeater. Those radios were made by Regency and were definitely very "cheap" in their construction. It took several complaints to the FCC before the taxi company finally installed traps in those radios to eliminate the spur.

Glen, K9STH

[K9STH]

AGK:

Actually, the "N" and "M" in the "Q" signals QRN and QRM have nothing to do with "natural" or "man made" noise.

"Q" signals were 3-letter combinations used to convey messages that were routine in nature (that were used on a regular basis) and thus could be condensed to 3 letters which would take much less effort to send using the International Morse code. The first 12 "Q" signals were adopted at the 1912 International Radiotelegraph Convention and were listed in the regulations from that convention. Additional "Q" signals were added at later dates. "Q" signals were considered a statement when sent. When a question mark ("?") was added then the "Q" signal became a question.

The first 12 "Q" signals included QRM and QRN. When sent as a question QRM? was defined to mean "are you being interferred with?". When sent as a statement QRM was defined to mean "I am being interferred with". This definition meant interference from another station.

When sent as a question QRN? was defined to mean "are the atmospherics strong?". When sent as a statement QRN was defined to mean "atmospherics very strong". "Atmospherics" was further defined to mean what we now call "static" and "static" can definitely be "man made" (i.e. from automobile ignitions, electrical devices such as motors, etc.).

As phone operations became common QRM was expanded to mean any interference by another radio station including those stations sending International Morse code. Today QRM also includes radio signals sending data as well as phone signals and code signals. As other types of noise (including those made by devices operated by man) QRN was expanded to mean any interference by a noise source OTHER than another radio station. Now amateur radio operators often include things like someone talking in the same room as the radio as "local QRM" and spurious signals from devices like computers as QRN.

However, there is nothing in the "Q" signals QRM and QRN that indicates "M" as "man made" or "N" as "natural".

Glen, K9STH

[N8GAV]

A wireless dog fence, the type that you drive stakes in the ground and bury the wire just under the grass.every time it rained the noise would drive me nuts 30 over at times.it took me over a year to find it when we moved in to our house. I had no clue it was all over my yard front and back untill I seen a power supply on the wall in my basement that I never noticed before and the transmitter was in a closet that we never used next to the basement steps. I was told that the dog wore a collar and when it would go over the wire it would get a shock. I un-pluged it and no problem since

[w8mkh]

Mother In Law :d

[AC0FP]

I have one known source of interference to my amateur radio operations, which I will designate QRWoman. My wife bought an expensive "kenmore HE2plus" washing machine. This machine carries a personal endorsement to the purchaser from "AlGore" that using this machine will save the Planet. It may save the Planet but it trashes the 20, 17, 15, 10 meter Amateur radio bands.:rolleyes:

[N9LCD]

The switching power supply in our counter-top microwave. I literally can see the pulses "walking across" the screen of a SDU attached to solid-state receiver tuned to about 154 MHz.

Ditto for an Office Depot house-branded paper shredder.

A HP Pavilion a818n computer. It generates enough noise to seriously "de-sense" a Bendix-King PRC-127 set to channels around 154.00 MHz.

JERRY

N9LCD

[vk4agk]

AGK:

Actually, the "N" and "M" in the "Q" signals QRN and QRM have nothing to do with "natural" or "man made" noise.

"Q" signals were 3-letter combinations used to convey messages that were routine in nature (that were used on a regular basis) and thus could be condensed to 3 letters which would take much less effort to send using the International Morse code. The first 12 "Q" signals were adopted at the 1912 International Radiotelegraph Convention and were listed in the regulations from that convention. Additional "Q" signals were added at later dates. "Q" signals were considered a statement when sent. When a question mark ("?") was added then the "Q" signal became a question.

The first 12 "Q" signals included QRM and QRN. When sent as a question QRM? was defined to mean "are you being interferred with?". When sent as a statement QRM was defined to mean "I am being interferred with". This definition meant interference from another station.

When sent as a question QRN? was defined to mean "are the atmospherics strong?". When sent as a statement QRN was defined to mean "atmospherics very strong". "Atmospherics" was further defined to mean what we now call "static" and "static" can definitely be "man made" (i.e. from automobile ignitions, electrical devices such as motors, etc.).

As phone operations became common QRM was expanded to mean any interference by another radio station including those stations sending International Morse code. Today QRM also includes radio signals sending data as well as phone signals and code signals. As other types of noise (including those made by devices operated by man) QRN was expanded to mean any interference by a noise source OTHER than another radio station. Now amateur radio operators often include things like someone talking in the same room as the radio as "local QRM" and spurious signals from devices like computers as QRN.

However, there is nothing in the "Q" signals QRM and QRN that indicates "M" as "man made" or "N" as "natural".

Glen, K9STH

Ok sth , you a lawyer? , genuine question there with no malice intended , so reading the above (i tried hard and where is the dotted line to signature?) and reading in-between the lines are not you saying "m" is from man (operator interference ect) and "n" is natural (loss of sigs ect) , a computer is man? made , lightning/static is natural or "g"

and going by my lawyer expertise ;) it looks like the m might have to be changed now to maybe g (gender) and "n" to "g"? also to keep everyone happy , lol....

[W0UZR]

I remember a guy telling this story about not finding interference for months. So finally he and another ham got a shortwave portable radio and walked around the neighborhood. The noise got pretty strong at a house 3 doors down or so. Knocked on the door and said they have interference on their radio, so fortunately she let them in. They walked around the house with the radio and it got real strong in the bedroom.

"May we check in your bedroom" they asked. She said go ahead and they found that the electric blanket stayed on 24/7. I can't remember if the ham bought her a different electric blanket or put something on the one she had to get rid of the noise, but he got it fixed.

[WB8MKV]

I used to get a 60 cycle noise on all bands. Threw the circuit breaker one breaker at a time...the culpret was a new electric blanket ( with a transformer) that would automatically turn off after ten hours. Solution...unplug the damm thing...

[K8MHZ]

Issue: 2 meter radio in car with static while engine running.

Cause: Old, dried out serpentine belt. Just as a part of maintenance the owner changed the belt and the static went away.....after spending hours trying to find the source of the static and finally giving up!

[ky5u]

The strangest?

AI4EP QRMing of the 3.955 group for me. Pretty strange. :eek:








:p
(Its a joke....)

[w8ixy]

In the mid 90's, several of the FM stations here in Cleveland were experiencing noise in their 950 mHz band Studio-Transmitter links. Occasionally, through the hash, we could make out the programming of one station. We coordinated shutting down that station's STL long enough to determine if their STL transmitter was causing the interference. When the first station contacted shut down their STL, another station's audio appeared! One by one, we shut off the STL transmitters, and immediately heard another station's audio. This was getting really weird. Finally after the sixth station shut their STL off, the interference disappeared. Now, at the time, the 950 mHz band was divided into separate chanels, spaced 500kHz apart. Modulation (at that time) was 500F3 or 250F3 depending on the license. Upon further investigation, we found that all the involved stations studios were located within less than a mile of each other, and all STL antennas were aimed in the same general direction (approximately south). What we found was that, due to even channel frequency spacing, any intermod problems would likely affect at least several of the stations, but where was it coming from?

We finally found the culprit. It was an "active" STL on-frequency repeater! One station had a dual "hop" for its STL path. The 10 watt STL main transmitter, about two stories above ground, was aimed at a receiving dish on to of a 15 story building, and coupled to an on-frequency RF amplifier that put out about 1 watt, aimed south toward the main transmitter on "RF Hill". The receive antenna was a 6 foot dish, and transmit antenna was a 4 foot dish, with plenty of isolation between them to avoid feedback from transmit antenna back to receive antenna. The "offending" transmitting dish was aimed south to the transmitter location (many of the Cleveland transmitters are about 10 - 15 miles south of the city on a high ridge.). What was happening was that the on-frequency STL amplifier had developed some serious non-linearities, and was mixing a half dozen broadcast signals all into each other, and radiating all that intermodded audio toward every station's STL receiver at that main transmitter location!

The fix: A simple rebuild of the offending station's on-frequency repeater. Although not ham radio related, that was the weirdest QRM situation I have come across yet.

73
Ted K8VPL

[kn4ds]

The strangest?

AI4EP QRMing of the 3.955 group for me. Pretty strange. :eek:

And here we all thought you didn't operate phone :D

[kf7qq]

Do you otimers remember the Russian Woodpecker??

[K9STH]

AGK:

If you look at the entire list of "Q" signals you will see that there is no real correlation to the letters used and the meaning of signal. Now a very few do have a letter that might be construed to have some bearing in the meaning but that is coincidental.

Go to

http://www.zerobeat.net/qrp/qsignals.html

For a complete list of "Q" signals.


The late K9BPV (the amateur who gave me my Novice Class examination in February of 1959) used the "Q" signal QBE when signing off for the night. Now Dave was a former aviation radio operator in the United States Navy and used that "Q" signal quite often when he was operating from an aircraft.

QBE means "I am about to wind in my antenna" or "I am reeling in my antenna". It was used on aircraft that had a trailing wire antenna that had to be retracted before the aircraft could land. Basically that signal was used instead of QRT because an aircraft with a retracted antenna could not transmit. Dave used it both on CW and phone. Of course someone who had not worked him before would usually ask what QBE meant and Dave would always explain the meaning.

At times I have been very tempted to use QBE while operating. But, so far, I have not.

Glen, K9STH

[VE1IDX]

Several years ago I sat down in front of the 6m rig hoping to work some DX that was running quite well. I was greeted by a horrid wideband signal that was about 30 over 9 in strength and 50-60 KHz wide. It was of course centered around 50.125 mainly but appeared in several other places at a reduced strength. I rotated the six element 6m yagi around trying to get an idea which direction the signal was coming from.I would get a full scale,needle pinning signal with the beam aimed south-west,straight at the neighbors house. I figured that was it. Tim has been a total moron with his dog barking all night long and his racing the car engine when he leaves in the wee hours of the morning for work,the constant use of my driveway to turn around in and even with his dog using my wife's flower garden as a litter box but no way in hell was he going to get away with jamming 6m on me.I grabbed a handheld scanner and tuned it to the jamming signal and marched out of the house towards Tim's house.As I approached his driveway I noticed the signal was fading.Hmmmmm....I thought. Strange. I walked up and down the road noting that as I got further from home the signal would get weaker.Having no signal strength meter on the scanner made it a bit hard to pinpoint where the signal was coming from. At some point I looked up at the tower and saw that not only was the 6m beam pointed at Tim's house it was also pointed directly at my own. I started to flip breakers off trying to locate the problem. Finally with the main breaker off the noise was still present.After an exhaustive search of the house I found the culprit. It was hidden in my son's large wooden toy chest in his room.It was a toy remote control with a button jammed.The thing actually was transmitting on 49.930 MHz but had trash all over the 6m band.I guess being modulated by a square wave will do that.As for the 6m DX'ing that night,well you guessed it. By the time I found the problem the band had died.

[vk4agk]

AGK:

If you look at the entire list of "Q" signals you will see that there is no real correlation to the letters used and the meaning of signal. Now a very few do have a letter that might be construed to have some bearing in the meaning but that is coincidental.

Go to

http://www.zerobeat.net/qrp/qsignals.html

For a complete list of "Q" signals.


The late K9BPV (the amateur who gave me my Novice Class examination in February of 1959) used the "Q" signal QBE when signing off for the night. Now Dave was a former aviation radio operator in the United States Navy and used that "Q" signal quite often when he was operating from an aircraft.

QBE means "I am about to wind in my antenna" or "I am reeling in my antenna". It was used on aircraft that had a trailing wire antenna that had to be retracted before the aircraft could land. Basically that signal was used instead of QRT because an aircraft with a retracted antenna could not transmit. Dave used it both on CW and phone. Of course someone who had not worked him before would usually ask what QBE meant and Dave would always explain the meaning.

At times I have been very tempted to use QBE while operating. But, so far, I have not.

Glen, K9STH

Ok. there Sth

[wb6mmj]

I had a repeater on Contractors point years ago. It was on 440.050 input and 445.050 out. The users kept getting knocked out of the repeater all the time. It took months but I finally found the problem. It was a packet link located in the next building. It was on 439.???. I Can`t remember exactly what the freq. was.
It wasn`t that hard to get rid of. They were NOT suppose to have those things on mountain tops where there were repeaters. I talked to the owner of it and told him to move it or it would notify the coordinating committee. It didn`t take long and it was gone. My repeater could hear again!
This was one of the hardest interference problems to find and just as hard to find the owner of it.
I`m so glad I sold all of my repeaters when I did.
I was the first repeater on 445.050, in Southern Calif., and had it for many years under the call of N6MNU.

[KI4NGN]

Last year my utility company company replaced my electric meter with a new digital model that could be read remotely. I came home from work the afternoon that this was done and found all sorts of HF interference, audible beginning on 80 meters, increasing in amplitude up through 20, and then decreasing again.

Hmmm.... what had changed? Well, a new wireless meter had been installed that very day, and I'd had no QRM the day before. Right to the phone, and the utility company was very cooperative.

They replaced the meter the next day, and when I came home from work I immediately turned on the rig. Not only was the QRM still there, but it was worse!

On the phone again, this time with techs very familiar with the meters, and it happens the one I was chatting with was a ham. I detailed the interference, told him what it sounded like, and as it happens what it looked like on my ProII spectrum scope. He explained the meters to me, the frequencies that they operated on, how often they transmitted, etc, etc. Came to the conclusion that it wasn't the meter.

The next day I purchased a handheld SW receiver on the way home from work. Walked all around the outside of the house with it, starting at the meter (of course), but finally got a peak reading on the far side of the house from the meter. This made no sense: the other side of that wall was my kitchen stove. Back inside the house I finally tracked it down to a wall-wart on one of my four cordless phones on the second floor! Apparently cutting the power for the original meter switch-out had caused something in this little darling to start getting noisy.

I felt guilty for having bothered the utility company, but at the time it did seem a very logical conclusion. Lesson learned. :)

Mike

[aa5te]

Cell phone charger = broad spectrum, low speed, high output sweeping QRM generator.

[WA7KKP]

Years ago we had a strange interloper -- an FM modulated carrier that meandered all through the 2 meter ham band. Only modulation we could hear were weak voices, and an occasional typewriter. Over a period of several hours it wandered up in frequency and started interfering with the local police on 155.610 MHz.

We traced the origin to the Yellowstone County Courthouse -- top floor. Yep, the county Hilton featuring striped sunlight. Seems they had a wireless bug in the detention area, and were reluctant to turn it off until the police chief told them it was interfering with his communications.

It took the hams to track that one down, and a little clout to get it stopped.

Gary WA7KKP

[wb6mmj]

I forgot about this one till now.
Back in my repeater days, I had two repeaters on mountain tops. One on Contractors point and the other on Verdugo peak, both in Southern Calif.
I started getting interference on both repeater inputs one day. I knew it wasn`t something local to their sites. Both got hit at the same time with the same interference.
It took weeks but I found where the problem was coming from. It was our local Channel 4 TV transmitter on Mount Wilson. It was spurious.
I contacted the TV station and told them about the problem. The lady I talked to on the phone said they were not having any problems with their transmission. We went round and round and I finally said that if you just have a engineer look at the signal with a spectrum analyzer that they would see that there is a problem. I also said that if the problem didn`t go away very soon that I would be contacting the F.C.C. about it.
Well, the next day the problem was gone. Guess they saw that they did have a problem. It never came back either.

[K9STH]

Several years ago the main county hospital in Dallas, Texas, decided to expand their medical paging. I had been contracted to that hospital for a couple of years to handle the paging equipment but they decided to save some money by going with someone else. The "new" company installed a 250 watt output Motorola transmitter (this was in the 450 MHz band). Within a few weeks there was severe interference to quite a number of commercial two-way stations.

One afternoon I got a telephone call from one of the FCC engineers who asked me if I still "took care of" the hospital's equipment. I told him that they had not renewed their contract several months before. He told me that the FCC had located the source of the interference to a tower that was only about 2 miles from my house and asked if I would meet him there even though I was no longer responsible for the equipment. He also contacted the owner of the tower and asked that a representative meet him there to open the building.

When we got there we discovered the Motorola 250 watt output transmitter and started examining it. The FCC engineer had me unlock the cabinet and then he started checking things. We discovered that the "new" service company had installed a crystal made by JAN Crystals in a Motorola "high stability" channel element and had not even bothered to get the crystal compensated for the channel element. In addition, JAN Crystals were not "type accepted" to be used in the equipment. Frankly, it was "taking off" and putting out all sorts of spurious signals. Not only was this happening the "new" service company had not even bothered to modify the hospital's license to add the transmitter to the system. Also, the output power was 2.5 times that which was specified on the existing license.

Since I was not responsible for the transmitter and legally could not disconnect it the FCC engineer turned to the technician representing the tower company. Since anything on the tower company's premysis was their responsibility the engineer had that technician unplug the transmitter from the AC mains.

Now the tower company did not get into any "trouble" with the FCC. However, both the hospital and the "new" service company did receive some VERY high fines. The hospital tried to get me to again contract with them for the paging system. But, I refused knowing that they would soon drop the contract just as soon as things "died down" and go to whatever company would do the work for the least amount of money. The hospital administrator who was responsible for the paging system knew that the license was not modified for the new site and also knew that what the "new" service company charged for the transmitter was substantially less than what the cost should have been.

Glen, K9STH

[vk6zgo]

I forgot about this one till now.
Back in my repeater days, I had two repeaters on mountain tops. One on Contractors point and the other on Verdugo peak, both in Southern Calif.
I started getting interference on both repeater inputs one day. I knew it wasn`t something local to their sites. Both got hit at the same time with the same interference.
It took weeks but I found where the problem was coming from. It was our local Channel 4 TV transmitter on Mount Wilson. It was spurious.
I contacted the TV station and told them about the problem. The lady I talked to on the phone said they were not having any problems with their transmission. We went round and round and I finally said that if you just have a engineer look at the signal with a spectrum analyzer that they would see that there is a problem. I also said that if the problem didn`t go away very soon that I would be contacting the F.C.C. about it.
Well, the next day the problem was gone. Guess they saw that they did have a problem. It never came back either.

I have been on the other end of one of these situations where a member of the "general public" rings up & bellows:

"WHAT"S THE MATTER WITH YOUR TRANSMITTER!".

The answer,after a quick check of the off-air signal is usually:

"Everything seems normal here sir".

"THE PICTURE IS TERRIBLE IT'S BREAKING UP & ROLLING!!!"

"Have you checked the other stations sir?"


"YES, THEY'RE ALL LIKE THAT!!"

"Sir,if they're all bad,it just may be your TV"


"Ohhh!"--------click!

People may after a while become so used to idiots that they don't recognise
someone with a valid problem.

It is a shame that there was no one who understood what your problem was. With the setup we had,we used 2 Transmitters day about,so one was always in standby.The obvious check was therefore,to change transmitters,which eliminated most of the likely culprits in one fell swoop.

Some years before this, I was working at an attended TV transmitter, when a ham well known to everybody on the Tx staff reported he was receiving SBS TV sound on 2 metres. I had my FT290R with me,so spent some time wandering around the site with no sign of the problem.

I did a bit a thinking & number crunching & came up with a theory. It was possible that a harmonic of the 2m Rx local oscillator was about 10.7 MHz away from the SBS sound carrier on around 500MHz or so ,& was producing a valid IF.

Rang the ham,who had been thinking along the same lines.

It turned out that the local osc operated at a lower frequency than required,& multiplied the frequency up with a simple diode multiplier.
This device still had enough o/p at UHF to create a valid IF.

The easy fix was a trap in his feedline to get rid of the UHF TV signal,rather than messing around inside the transceiver.

73 VK6ZGO

[NN3W]

Do you otimers remember the Russian Woodpecker??

Sorry for rehashing old threads.

But I was finally fowarded a link to the "classic" woodpecker. It sounds like the audio stream was in AM mode, so the harshness of the pecker isn't as noticeable, but this is indeed our hated "bird":

http://upload.wikimedia.org/wikipedia/commons/5/5b/Woodpecker.ogg

[N2RJ]

The hardest to find was a switching supply in a subwoofer in my home theater system, made by, of all people - KENWOOD!!!

That thing would provide a nasty AC hum on 40m, which totally wiped out a portion of the band for me.

[ad5nd]

Do you otimers remember the Russian Woodpecker??

The Russian woodpecker was annoying, but it did help to find the MUF.
The hardest to find QRM was my cell phone. It would generate a strange pulse type noise when it lost its signal.

[N2RJ]

A couple of weeks ago I also finally decided to troubleshoot a nasty noise problem I was having on 17m.

I carried a portable sw radio tuned to the 17m band with its antenna retracted. I finally ended up in the living room.

Turned out it was an ionic breeze that we recently put back into service.

Looks like we're getting a HEPA air purifier instead now.

[N2RJ]

Sorry for rehashing old threads.

But I was finally fowarded a link to the "classic" woodpecker. It sounds like the audio stream was in AM mode, so the harshness of the pecker isn't as noticeable, but this is indeed our hated "bird":

http://upload.wikimedia.org/wikipedia/commons/5/5b/Woodpecker.ogg

I used to hear that when I was SWLing with my dad in the 80's. I actually never found out what it was until I entered secondary school and got interested in ham radio.