Hello to the list, I enjoy very much reading the problems and=20
responses that come through here. I have solved quite a few=20
interference problems myself both professionally and on an amateur=20
level.
=46irst some background...I am a broadcast engineer for KFI AM 640 in=20
Los Angeles. Since we are "talk radio" we operate in 10 second audio=20
delay to our main transmitter for obscene language deletion and=20
liability issues. This makes it impossible to receive at a remote=20
site or in our traffic reporter's aircraft over the air. So, I put=20
up a transmitter on 450.725 mHz that puts our audio signal out in=20
"pre-delay" 24 x 7. We are licensed for 55 watts tpo and around 800=20
watts erp on Mt. Wilson.
Here is the problem...I got a call from a ham 80 miles away that=20
claims he is hearing my 450.725 transmitter on 448.060 mHz. Its not=20
a mix, its just there all the time. He is using a Premier PR-460=20
hand held and we are coming in strong. That is a frequency=20
difference of 2.665 mHz. I did some research and determined that the=20
radio uses a 21.4 - 455 IF. To me, this does not make any sense.
Of course I will check my 450 transmitter just to make sure I have=20
not developed a spur with more power than my center channel. I can't=20
imagine I have because there are enough hams in LA who know me well=20
enough to let me know of problems like this before it would become a=20
issue.
My question is...has anyone had any experience with this or any other=20
radio and a possible off channel response? I seem to recall my VX-5R=20
(before I lost it) had a similar response around =B1100kHz or so. Does=20
anyone know what this could be caused by? I am considering injection=20
spurs out of the synthesizer as the only possibility.
Anybody?
tony dinkel
wb6mie
kfi am 640, more stimulating talk radio; klac 570, not just facts,=20
feelings; kxta fox sports 1150
http://www.tonydinkel.dynip.com/
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