North London and clashing signals

"Brian Gregory [UK]" wrote in message
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"Brian Gregory [UK]" wrote in message
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"Mark Carver" wrote in message
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On 08/06/2010 23:19, Brian Gregory [UK] wrote:
"john wrote in message


Gold is on 1548kHz in London, right?

There's no BBC world service anywhere near that as far as I know.

Capital Gold 1548 kHz

BBC World Service 648 kHz

1548-648= 900kHz

900/2= 455 kHz

I make it 450kHz.

But 455kHz might be near enough for it to be a problem.

Also some digitally tuned radios do use a 450kHz IF.


455 kHz the local oscillator frequency for many MW radios.

No, it's the IF frequency.


Therefore BBC World is appearing 'on top of' Capital Gold as a 2xIF
image.

As Charles says, crap receiver design/quality.

This always happens to some extent with most designs but normally isn't a
big problem except when the unwanted signal is very strong.

I'm surprised the BBC WS on 648kHz is strong enough to cause this problem
in London. It's appalingly weak here in Reading since they introduced the
latest directinal antennas to beam 648kHz towards europe.

Actually I've just looked through the rest of the thread been nudged into
realizing that it's not that way round. Any normal single conversion
receiver will have problems with strong signals from twice it's IF *above*
the frequency it's tuned to.

I wonder if the problem could be that the OP is actually tuning to around
648kHz when he wants to hear 1548kHz and getting enough 1548kHz through
(because it's really strong) for him to think he's tuning correctly.

Knowing the exact make and model of the radios would help figure it out.

--

Brian Gregory. (In the UK)

To email me remove the letter vee.