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Re: Downconverter noise




On Tuesday, May 27, 2003, at 01:53 America/Chicago, Howard Long wrote:

> I might have misunderstood the question, but of the 50 or so AIDC 
> 3731's
> I've distributed here in the UK, all of them have produced a very
> significant increase in noise level and S meter reading when hooked up 
> to
> the half a dozen different radios I've used them on (and no antenna, 
> dish or
> feed connected). S5 is about ball park but due to the vagueries of S 
> meters
> it might be S3 or it might be S7.

Well, then I guess I stand corrected.  But it just doesn't make sense.  
If the d/c is at S5 with no antenna and no signal, then you are already 
at least 10 to 15 dB above the noise floor of your radio.  Does the 
noise actually go DOWN once the antenna is mounted on the dish and put 
in place?

I can tell you that form my experience you do hear an increase in noise 
with the d/c on, but it certainly isn't enough to move the s-meter more 
than a unit or less.  It's certainly not 5 units.

I'm confused..

73,

Jon
NA9D

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