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Re: [Amps] Transceivers

To: Will Matney <>
Subject: Re: [Amps] Transceivers
From: peter.chadwick@Zarlink.Com
Date: Mon, 6 Sep 2004 08:33:01 +0200
List-post: <>
Bill said:

>But if  the local oscillator signal  is strong enough to simply turn on 
and off the mixer tube it does become a very effective >frequency mixer. 
It then appears to be an analog mixer multiplying a signal with a square 

It does reduce the conversion gain, though. That's the big problem with 
switching mixers. The so called 'Gilbert cell' (which Barrie Gilbert 
doesn't claim as his -  it was first patented by a guy from RCA as a 4 
quadrant multiplier -  Barrie's claim is that he was the first to suggest 
using it as a mixer, and even that's disputed) can be oeprated in lower 
gain as a switching mixer, and in higher gain as an analogue multiplier 
type mixer, with lower LO drive and worse IMD performance. It also is more 
susceptible to AM on the LO.


Peter G3RZP.
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