Re: {Collins} Difference between 75S-1 and 75S-3

In the manual the instructions say to use the variable BFO when using the CW filter.  That way, the received tone can be varied to whatever is pleasing to the operator.

I have added a 455.8 kHz crystal to my 75S-3A like was done with the 75S-1 / 75S-2. This is a very simple modification.  That way the received tone is 800 Hz when the signal is centered in the pass-band.  You can still use the variable BFO without any problems.

 Glen, K9STH 

      From: Alan Victor <amvictor@xxxxxxxx>
 To: Glen Zook <gzook@xxxxxxxxx> 
Cc: Bill Carns <wcarns@xxxxxxxxxxxxx>; Brian Gieryk <ke6iyc@xxxxxxx>; "COLLINS@xxxxxxxxxxxxx" <COLLINS@xxxxxxxxxxxxx>
 Sent: Sunday, October 29, 2017 6:25 PM
 Subject: Re: {Collins} Difference between 75S-1 and 75S-3
Glen, Bill... what about the change in the BFO xtal frequency near 455 kHz from the standard issue in the -3 equipped with 200 Hz. CW filter?  I do pretty much CW and the issue with the 200 Hz filter once tuned properly is the CW pitch is too high for my taste. If CW is a favorite mode of operation, I would recommend the altered xtal freq. Sorry, would need to look it up, not at my finger tips the xtal frequnecy. Alan 


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