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Old 5th Jan 2023, 12:44 am   #115
Bazz4CQJ
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Join Date: Apr 2009
Location: Oxfordshire, UK.
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Default Re: Improving Selectivity In Vintage Receivers

Ok, this is the circuit sent to me from Andrew; I think the original was over 1MB so was over the limit for attachments.

The comments he made were, "Note the top of the IFT going to V6 grid has been cut and grounded. The bottom wire under the chassis is taken from the AGC line and goes to the filter".

The idea of putting the circuit between the 1st and 2nd if is interesting.

I think Jon and myself would both like to have HRO's which cope better with SSB than they do in their original config. but quite what we each want, and how we might get there are still a bit hazy. As mentioned before, the thread was not intended to be specific to HRO's and might equally interest anyone with any one of a number of old receivers which lack selectivity control.

As I have already taken the HRO crystal filter out, I could think of copying Andrews circuit but maybe putting in a stage earlier. Were I go from here needs thinking about!

B
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Last edited by Bazz4CQJ; 5th Jan 2023 at 12:54 am.
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