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RE: Downconverter noise

Hi Jon

> 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 wonder how much gain your d/c has? The 37dB of the AIDC 3731/3733 is very
high - many of us pop in 10-20dB of attenuation in the IF. Maybe your d/c
has lower gain?

The point of the d/c gain is to make the noise figure of the IF receiver and
the feeder between it and the d/c become insignificant - and 37dB is
certainly more than enough! The d/c's front end noise is being amplified too
of course, which is what you're hearing in your radio when you plug in the

Either way I think we're agreed that you should be able to hear a
significant noise increase when the d/c is plugged into the receiver, with
or without an antenna attached.

Cheers & 73, Howard G6LVB

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