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Author Topic: CB on the 13M band?!? 21.885 MHz 21885 kHz AM  (Read 263 times)

Offline ThaDood

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CB on the 13M band?!? 21.885 MHz 21885 kHz AM
« on: November 17, 2018, 2330 UTC »
Raised a Windom another 5ft, so tuned around 15M. Nothing... Continued into 13M and heard AM on 21.885MHz at 22:50UTC, 11/17/2018. To my surprise, it sounded like truckers using that FREQ as CB. Certainly different.
« Last Edit: November 28, 2018, 1500 UTC by R4002 »
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Offline R4002

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Re: CB on the 13M band?!?
« Reply #1 on: November 20, 2018, 2120 UTC »
Interesting indeed.  The furthest down I've heard truckers is 25 MHz, so 21 MHz is a new one for me.  That's well beyond the reach of all of the radios usually available to truckers as CB.  The fact that its in AM mode is interesting though.  Maybe you're hearing a spur or image of CB traffic? 
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Offline R4002

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Re: CB on the 13M band?!? 21.885 MHz 21885 kHz AM
« Reply #2 on: November 28, 2018, 1503 UTC »
I went ahead and added the frequency to the subject line in case somebody else finds the same thing and Googles it.  I did some research and as far as I can tell, even the super high end export rigs available to truckers don't get down below 24 MHz.  24.265 MHz is the lowest frequency on the Superstar 158EDX radio (it covers 24.265 MHz to 29.655 MHz), the RCI-2950 and RCI-2970 series radios cover 26.000 MHz to 32.000 MHz and the Chinese 10 meter rigs cover 25.615 MHz to 30.105 MHz....making your find on 21.885 MHz AM quite an interesting one.
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Offline Σ

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Re: CB on the 13M band?!? 21.885 MHz 21885 kHz AM
« Reply #3 on: November 28, 2018, 1546 UTC »
Could that possibly be an image? It is exactly 5.3 MHz below 27.185 MHz, Channel 19.
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Offline R4002

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Re: CB on the 13M band?!? 21.885 MHz 21885 kHz AM
« Reply #4 on: November 28, 2018, 1850 UTC »
I was thinking it was an image or perhaps a spur resulting from a CBer running a badly filtered and/or overmodulated radio+amplifier setup as well.  The furthest down in frequency I've heard truckers and CB traffic is the 25 MHz band.

I remember many years ago in local CB lore there was a certain operator who had a radio with the modulation limiter clipped out and an amplifier driving an even bigger amplifier...both of the amplifiers being of the DAVE MADE homebrew splatterbox variety...he was splattering all over 12 and 10 meters as well as producing harmonics on the VHF aircraft band...which resulted in the FAA calling the FCC and that was that.   
« Last Edit: November 28, 2018, 1856 UTC by R4002 »
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Offline Josh

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Re: CB on the 13M band?!? 21.885 MHz 21885 kHz AM
« Reply #5 on: November 28, 2018, 2010 UTC »
What rx did you employ to monitor said traffic?
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