[Hallicrafters] S 76 Question

[lrlayton at cox.net]

Have a S-76 here without an antenna trimmer. It does not have 15 meters so its probably an ealier run, but does have skirted knobs. The cabinet except for the holes in the bottom for adjustments is identical to one for  a Hallicrafters 8R40 ( similar to S-40B, but with a sliderule type dial). 

Les 



---- Mike Everette <radiocompass at yahoo.com> wrote: 
> I've never seen an S-76 with a factory antenna trimmer.  I have original copies of all 3 versions of the S-76 manual, and none show one, to the best of my recollection; admittedly I haven't looked at them in a while.
> 
> There was an article in QST some time in the 1954-56 period which detailed putting a trimmer in the S-76 as well as adding an audio-response modification circuit which involved a switch on the front panel.  The antenna trimmer was apparently a popular mod that worked well.  I've seen numerous S-76 receivers on eBay with the addition, all done slightly differently depending upon what parts were used.
> 
> The article also suggests substituting a much larger, weighted knob for the bandspread tuning.  This is a definite plus, as the S-76 tuning is very twangy with little feel to it.  Makes it almost like a new receiver.
> 
> Seems like, from what I can gather, the skirted knobs came after the first run.  Also, the 2nd and 3rd runs added 15 meter bandspread.
> 
> A long time ago on this forum, someone suggested rewiring the detector and AVC in the S-76 to match that in the SX-100.  This would allow use of the AVC on CW and SSB, so that big S-meter can shake-shake-shake.  It would involve a tube change from a 7 pin to a 9 pin tube, but if you have a chassis punch for 9 pin sockets that should be no problem.
> 
> I'm sure someone will suggest putting a 6BY6 product detector on board, like in the SX-101A; but that may be going a little far... go get an SX-111 Mark 1, which is not at all a bad radio.
> 
> The SX-100 without the notch filter was not an SX-100, but an SX-96A.  The 96A added the trimmer and an onboard crystal calibrator, which are the two most valuable mods.  I have a 100 and the notch filter does work; but I hardly ever use it.  To me, any general coverage 2-dial receiver is of limited value without a calibrator somewhere, even if it's external (like a BC-221/LM).
> 
> 73
> 
> Mike
> W4DSE
> 
>  
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