Need Info on Hallicrafters SX-28/SX-28A Modification
 

I have seen pictures of several SX-28 or SX-28A receivers that have
what appears to be an additional IF stage modification. This mod is
right in front of the power transformer, and has a miniature tube
(6BA6 ?) and an IF can mounted on a small sub-chassis.

I would appreciate any information regarding this modification. A
pointer to anything published would be ideal.

Thank you.

73,
Jeff
N6MNI

Need Info on Hallicrafters SX-28/SX-28A Modification
 

Although I am not familiar with an additional if stage, it seems there would
not be much advantage in adding such a stage. Any additional gain would be
at a cost of reduced dynamic range.

I would be more inclined to think it was a product detector circuit, using a
6BE6.

Colin K7FM

Need Info on Hallicrafters SX-28/SX-28A Modification
 

On Nov 18, 7:44 am, "COLIN LAMB" wrote:
Although I am not familiar with an additional if stage, it seems there would
not be much advantage in adding such a stage. Any additional gain would be
at a cost of reduced dynamic range.

I would be more inclined to think it was a product detector circuit, using a
6BE6.

Colin K7FM

A product detector was also my first thought, but why the IF can?

73,
Jeff

Need Info on Hallicrafters SX-28/SX-28A Modification