[Boatanchors] National SW-54 "CWO-IF AMP"

Steve Mulder smulder3 at cox.net
Mon Oct 17 12:13:46 EDT 2011

I would like to thank everyone who replied offline to my question about 
the "CWO-IF AMP". I understand how it works now. A number of people 
pointed out that a similar circuit was used in the Hallicrafters S-38 
series of receivers, and that this type of circuit was inferior to a 
'real' BFO.

In some further reading on this topic, I came across a website that 
showed how to add a tiny BFO to an S-38:

Thanks for all the help.

Steve Mulder

On 10/16/2011 10:22 AM, Steve Mulder wrote:
> I read that the National SW-54 does not have a BFO, but it does have a 
> "CWO-IF AMP". Could someone here give me a brief explanation of how a 
> CWO-IF AMP results in an audio tone for CW signals?

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