[Hallicrafters] SX-42 Circuit variations (?)

[Roy Morgan]

At 02:14 PM 1/20/2006, W7QHO at aol.com wrote:
>I'm currently in the process of restoring an SX-42.

Dennis,

Good for you and the radio. 'Glad to hear of another one making it's way 
back to usefulness.

>...significant deviations in the component values and circuit 
>details...Hallicrafters Service Bulletin (Nov. 1947, 94X242). ...Sams 
>Photofact Folder dated 8/48

Yes, there are variations. I don't have good information on all this, but 
I've been working with Bob, W0YVA on his SX-42 recently:
http://www.isquare.com/personal_pages/sx42.htm
   One main difference we found comparing schematics and actual radios is 
in the detector/noise limiter circuit. In some cases, only half of the 6H6 
is used, in others both sides are used and there is a tap on one IF 
transformer.  If you have found this, I think there is little hope of 
changing things to the tapped transformer version unless you get a 
different transformer.

By the way, on that link above, you can get a new decal/sticker to restore 
the little curved arrow on the fine tuning lock knob. They seem to be all 
disappeared from radios we have seen, and Bob has them for a modest cost.

>Would appear I have an earlier/later model than that described in the data I
>have.   Anyone know more?

I look forward to any details that list members might have.

Roy

- Roy Morgan, K1LKY since 1959 - Keep 'em Glowing!
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