W3JDR wrote:
Heikki,
I'm not sure exactly what this particular circuit looks like, but I strongly
suspect it's just a balanced mixer made from 4066 analog switches. I have
used this technique and it is quite good at low IF frequencies (a few MHz or
less). Are you sure you have the switches biased properly? The thru-path
should be biased at about 1/2 of the 4066 DC supply voltage in order to
avoid severe signal clipping. Can you point to a link where the circuit is
shown??
The circuit can be found in QST Nov 1992 (Recent Advances in Shortwave Receiver
Design)! I t is unclear whether only two switches are used or if each switch is
actually two in parallel. The biasing should be OK!
73 de Heikki
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