Re: [AMRadio] interference from 3810 khz to 3910 khz
I have heard that some consumer electronics that use microcontrollers operate with FM'ed clocks to reduce the Part 15 emmissions by spreading it out. And many appernetly use clocks in the 75M range. Bob Macklin K5MYJ/7 Seattle, Wa. "REAL RADIOS GLOW IN THE DARK" - Original Message - From: "Geoff" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Tuesday, July 12, 2005 10:12 AM Subject: Re: [AMRadio] interference from 3810 khz to 3910 khz > kenw2dtc wrote: > > > "Anyone else picking up interference from 3810 khz to 3910 khz ? It > > sounds like a swept buzzsaw" > > > > ***I work the 3870 to 3890 portion of the band and every once in a > > while, I hear it slide through the frequency like a slow VFO. Others > > on frequency from NJ to Maine also hear it. It's not on all the time??? > > > > 73, > > Ken W2DTC > > > > __ > > > I hear that in south Texas, too... > > When I hear it on some of the higher frequencies, I always thought it > might be an audio version of where the MUF was... > As screwy as the sunspot cycle has been, the MUF could have been as low > as 3.9MHz. > > > --- > 73 = Best Regards, > -Geoff/W5OMR > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net >
Re: [AMRadio] interference from 3810 khz to 3910 khz
kenw2dtc wrote: "Anyone else picking up interference from 3810 khz to 3910 khz ? It sounds like a swept buzzsaw" ***I work the 3870 to 3890 portion of the band and every once in a while, I hear it slide through the frequency like a slow VFO. Others on frequency from NJ to Maine also hear it. It's not on all the time??? 73, Ken W2DTC __ I hear that in south Texas, too... When I hear it on some of the higher frequencies, I always thought it might be an audio version of where the MUF was... As screwy as the sunspot cycle has been, the MUF could have been as low as 3.9MHz. --- 73 = Best Regards, -Geoff/W5OMR
Re: [AMRadio] interference from 3810 khz to 3910 khz
>From the northeast I can offer the following for 75: - swisher/sweeping sound, travels up and down the band (this might be what you're hearing, Mark) - beep/buzz/duck sound, also travels the band and easily recognized by its steady short, duck-like quack/buzz sound *bzzt* *bzzt* *bzzt* *bzzt* - the sound from hell, which varies between a screeching buzz to more of a roaring sound, usually starting high-pitched and slowly going to the lower frequency roar. These sounds are heard by AMers all over the northeast, as well as elsewhere. I've probably missed a few. Some have tracked one of the sounds to (possibly) the Bath Ironworks or that vicinity, suggestions include some kind of industrial heating device. Wonder if any of it comes from Brunswick? Other odds sounds like the marching duck sound would be much harder to locate. Most seem to wander around the band after hammering one frequency for a while. Some of the more steady and strong signals located at fixed points on the band are indeed local to me. For example, my Dish satellite receiver wipes out most of 40 and up but doesn't seem to bother 75. Even the VCR and other electronics make racket while shut off. My solution was to add a terminal strip with a switch to plug it all into, that can easily be shut off for listening. Satellite receiver needs to reboot everytime, which is annoying, but it sure quiets things down. On 7/12/05, Geoff <[EMAIL PROTECTED]> wrote: > Mark Foltarz wrote: > > >Anyone else picking up interference from 3810 khz to 3910 khz ? > >It sounds like a swept buzzsaw. > >10:15 EST QTH is NE Ohio. > > > > > > > > It's interesting to note, however, that this morning on 75m, a station > 15miles away > and running 300w was S-7, while a 175w station 300 Miles away was 20db/S-9. > > typically, it's the other way around. when I signed, both of them were > unreadable > at my house, and line noise had crept up to S-8. > > Strage this morning, on 75m, from 7am to 8:30am, CST > > 73 = Best Regards, > -Geoff/W5OMR > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net >
Re: [AMRadio] interference from 3810 khz to 3910 khz
"Anyone else picking up interference from 3810 khz to 3910 khz ? It sounds like a swept buzzsaw" ***I work the 3870 to 3890 portion of the band and every once in a while, I hear it slide through the frequency like a slow VFO. Others on frequency from NJ to Maine also hear it. It's not on all the time??? 73, Ken W2DTC
Re: [AMRadio] interference from 3810 khz to 3910 khz
Mark Foltarz wrote: Anyone else picking up interference from 3810 khz to 3910 khz ? It sounds like a swept buzzsaw. 10:15 EST QTH is NE Ohio. It's interesting to note, however, that this morning on 75m, a station 15miles away and running 300w was S-7, while a 175w station 300 Miles away was 20db/S-9. typically, it's the other way around. when I signed, both of them were unreadable at my house, and line noise had crept up to S-8. Strage this morning, on 75m, from 7am to 8:30am, CST 73 = Best Regards, -Geoff/W5OMR
Re: [AMRadio] interference from 3810 khz to 3910 khz
Jim Candela wrote: Mark, I have something similar here in Round Rock, Texas. I discovered that my DVD / VCR combo squirts out RF like crazy whenever it is turned off. Whenever I want to listen to 75 meters, I need to unplug the POS. Maybe the interference your seeing is in your own house, or maybe not. Time to put your detective hat on.. Point Of Sale? ;-)
Re: [AMRadio] interference from 3810 khz to 3910 khz
Mark, I have something similar here in Round Rock, Texas. I discovered that my DVD / VCR combo squirts out RF like crazy whenever it is turned off. Whenever I want to listen to 75 meters, I need to unplug the POS. Maybe the interference your seeing is in your own house, or maybe not. Time to put your detective hat on.. Regards, Jim WD5JKO --- Mark Foltarz <[EMAIL PROTECTED]> wrote: > Anyone else picking up interference from 3810 khz to > 3910 khz ? > It sounds like a swept buzzsaw. > 10:15 EST QTH is NE Ohio. > > de KA4JVY > Mark > > > > __ > Do you Yahoo!? > Read only the mail you want - Yahoo! Mail SpamGuard. > > http://promotions.yahoo.com/new_mail > __ > AMRadio mailing list > Home: > http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net >
