[Milsurplus] [Boatanchors] Tube radio Product detectors

[Robert Nickels]

On 7/10/2010 8:32 PM, Greg Mijal wrote:
> Rock the mode switch to SSB and poof! rig is now receiving normally and stays that way for whole time it is used.  What causes this?
>    
Hi Greg,

My guess would be that all those rigs use a product detector.   As you 
probably know, "product detector" is just another name for a mixer, and 
if either the IF signal or the injection signal from the BFO are 
missing, the output will be basically zilch.   Since you can restore 
operation by fiddling with the mode switch, I'd bet there's just a dirty 
contact that is preventing the BFO signal from getting through 
properly.  De-oxit time!

73, Bob W9RAN