[Hallicrafters] SX-42 BFO mod

[W7QHO at aol.com]

In a message dated 11/3/07 10:26:31 AM, zuu6k at juno.com writes:


> Has anyone heard of a BFO mod to the SX-42? I assume it was to get a
> stronger BFO injection. Thank you.
> 

Ed,

I modified the BFO in my sx-42 to make it a self excited 6AS7 product 
detector.   Included some AGC mods as well and achieved excellent results.   Doing 
this required dispensing with a BFO on the top two bands but haven't found this 
to be a problem.   Since the original BFO circuit also doubled as an S-meter 
amplifier I replaced the 6H6 noise limiter with a solid state diode and used 
the socket for a 6J5 meter amp.   All together, a somewhat complex undertaking.

Some may consider the above a mutilation of a classic but the old 42 is now a 
FAR more useable and enjoyable receiver.   Added an on-chassis 100kc xtal 
calibrator too while I was at it along with a full recap job.

Dennis D. W7QHO
Glendale, CA



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