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Old September 24th 03, 07:39 PM
mike
 
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On Wed, 24 Sep 2003 15:47:10 +0200, Stephan Grossklass
wrote:

Dale Parfitt schrieb:

Cool, that beats my picking up 50 kw Radio Orbita 3 from Russia or the
African channels (Botswana and Nigeria) booming last night.

Not bad for a sony 7600GR portable eh?

I figured out the image problem. I think it's the voltage limiting
diodes I place yesterday across my antenna input to ground.


That is exactly what it is assuming yor RX uses a 455 kHz IF.


Which, btw, it does. And it doesn't have too great an image rejection
either (~40 dB). When using a big antenna with a 7600G(R), I'd advise a
passive preselector / antenna tuner, not only for better image rejection
but also against IM products (here in Central Europe signals are strong
enough to produce IM products on the whip alone). It's a lot of receiver
for the money, but in no way an AR7030+... (Except for AM demodulation,
that is - this sounds rather crappy and distorted on the AOR, but that's
what the excellent synch is for.)

Stephan



Hmmm...guess the diodes are not such a hot idea after all.
Easy enough to desolder and remove them. That would leave my 2.2k ohm
resistor as a bleed off inside my antenna tuner. I will order a gas
arc breakdown tube for major voltage impulses and be done with it.
Or alternately, should I run into a pile of cash sometime soon, buy an
ICE model 197 RF limiter/arrester.

mike