[Hallicrafters] S 76 Question

[Mike Everette]

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