Re: Buzz on 20m
I'm not sure what Jerry was hearing or seeing. There are no reports of any OTH facilities inside the US. The OTH radar on HF ham bands has been a problem in Europe and beyond. It pops up here on the east coast fairly often. You can Google OTH and various ham radio message boards and find a lot of info. The radar operates by choosing a frequency based on the MUF and propagation at the radar site. Sometimes this frequency will be in the middle of a ham band. The radar will change frequency regularly. I've attached some screen shots I took on different bands. Note the times in UTC. This interference is only a few kHz wide as you can tune the radio up and down the frequency and it will go away. All of these were on standard PSK31 frequencies. RX tuned to 10.040, 14.070, 21.070 and 7.070. The 40 meter signal looks different so I'm not sure what it is? Maybe they change the PRF or it is from a different source altogether.
I have worked thousands of EU stations on PSK as I'm actively pursuing EPC Awards and the EPC gurus have triangulated and DF'd the interference and say it is definitely coming from Iran.
I know some other east coast 070 Members have mentioned this interference from time to time.
Also, I'm in a very rural area. Mostly farming and swamplands. No cable TV, no DSL, I get WiFi from a local provider that has his set up on top of a farmer's grain bin and I have no plasma TVs. I think there are 3 residences within a 1/4 mile of here. I do occasionally get some electric fence pulsing on and off on 160 meters. I'm familiar with powerline interference and it is different.
Have fun. There are some 15 meter PSK31 signals here this morning so it is good to see some improvements in propagation.
Bill N4GBK in eastern North Carolina
From: 070@... <070@...> on behalf of 'ljl2002@...' joe_molon@...  <070@...>
Sent: Tuesday, July 19, 2016 12:37:44 PM
Subject: Re:  Buzz on 20m
I did the AM radio trick several times in the past and it works great. Both were outside the QTH.
Once I found an arcing fuse on a pole and another time I found a bad switching power supply on a pole which was used for lighting control. One big clue was that it only happened at night. Once I told the town they had their contractor come out and replace it.
Ahhh....the sweet sound of.....nothing!
On Tuesday, July 19, 2016 4:16 AM, "Jerry n9avy@... " <070@...> wrote:
Nope, as Bill, N4GBK, said it's probably OTH (Over The Horizon radar) or similar on 20m. It only happens for a short time and appears to be some sort of communications. Definitely not anything at my QTH: if it were in the house it would happen all the time at regular intervals. It almost has to be here in US because band wasn't open to Europe/Asia or anywhere overseas.
It's just annoying when it's on but not as annoying as those really wide 20m PSK signals or those using RTTY, MFSK, or have their mics plugged in when sending on PSK... this morning I even heard music !
Geez, what ever happened to hams who cared about their signals ?
Jerry N9AVY #454
From: "'Milton Garb' n6mg@... " <070@...>
Sent: Monday, July 18, 2016 11:11 AM
Subject: RE:  Buzz on 20m
Before turning to the masses for a thousand different scenario’s, & opinions, have you checked your collapsible shack and household for a buzzing wall wart, or even the little red/green L.E.D. that signifies power to your tv?
I get it on 30m rarely, but unplugging my wife’s flat panel tv in the kitchen cures it.
I found it by taking a little $5 battery powered AM radio and going from room to room.
From: 070@... [mailto:070@...]
Sent: Monday, July 18, 2016 7:30 AM
To: yahoogroups <070@...>
Subject:  Buzz on 20m
Does any have any idea what that raucous buzz is that sometimes covers all the PSK stations up ??? It shows as a bunch of vertical lines all across the waterfall. Just curious...
Jerry N9AVY #454