| Author |
Message |
    
Kirk
Intermediate Member
Username: Kirk
Post Number: 291
Registered: 6-2002
| | Posted on Friday, July 08, 2005 - 5:33 am: | 
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Sent to me from a friend.----
“A perfectly demodulated 104.1FM broadcast appears at 1447.5 KHz. No carrier of course, turning the BFO on results in no beat. Additionally, unlike typical "slope detection" of an FM signal on AM, this is perfectly clean and enjoyable to listen to. Now to make it better, the phenomenon is manifested in multiple receivers, all with different first IF stages, making me think it is not an internally generated component, but rather off-air mix. It's weird!”
Regards-- Bob
Any thoughts?-- Kirk
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Hollowpoint445
Advanced Member
Username: Hollowpoint445
Post Number: 517
Registered: 6-2004
| | Posted on Friday, July 08, 2005 - 3:49 pm: |
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Is your friend nearby the transmitter for 104.1MHz? What kind of signal strength does he have on 104.1MHz and 1447.5MHz? Does this only happen on attached antennas? What happens when he uses an external antenna? Can he tell the direction it's coming from or where it's strongest? He should be able to home in on it by using a small battery powered radio.
It sounds like the signal is being mixed with another oscillator nearby. It could be almost any kind of radio, but probably a cheaper radio with a plastic cabinet. |
Kirk
Intermediate Member
Username: Kirk
Post Number: 293
Registered: 6-2002
| | Posted on Saturday, July 09, 2005 - 10:40 am: |
|
He was going to investigate what your asking Hollow. He is somewhat near the Transmitter site...maybe 20 miles away. I've had this happen to me before on a clock radio. I'll find out what I can. Thanks for your input-- |
Kj7gs
Junior Member
Username: Kj7gs
Post Number: 28
Registered: 12-2004
| | Posted on Saturday, July 09, 2005 - 10:55 am: |
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1447.5 KHz or 1447.5 MHz??? I'm thinking intermod either way. |
