I had been looking for an S-76 for quite some time. I like meters and I couldn't help but to be attracted to the rather large S-meter of the S-76. The problem was that they don't come up for sale often and when they do the paint is often very tired looking on them. Hallicrafters black at the very least seems to have been applied thinly at the factory and therefore is very susceptible to scratches. After a few responses from a few folks I put the idea aside for a bit and decided to be patient until the right one came along. I hadn't really thought of the idea when I went to the NOBARC ham fest and there sitting on a table was an S-76 in very fine shape! The paint looked nearly untouched with only small scratches on the side. It was priced about half what others had been asking for theirs and so it took very little convincing for me to bring it home. When I took a look over it for the first time I was a bit surprised to find that the capacitor that went across the primary of the output transformer had been disconnected. I'm not entirely sure why this was done... Thankfully save for a single modification outlined in a 1954 QST article and a replacement cathode bypass capacitor the radio was essentially untouched.
Another item that caught my eye was that it was wired in a slightly haphazard way. The solder joints all looked fine and no component leads were touching each other but it just didn't look very nice. I proceeded to spend about 100-120 hours removing each component, trimming the heads, bending the leads to either a 45 or 90 degree angle, removing the remaining clipped lead from the terminal eyelet, reinserting the component, soldering it, gently removing the solder flux with a small wire brush, applying 91% isopropyl alcohol to the joint to clean it, inspecting the solder joint for quality, readjusting the leads of the component if necessary and then moving onto the next component.
Each capacitor lead is covered first with rubber insulator (taken off of a spool of insulated wire) and then that is covered with black cloth off of some spare cloth covered wire I have. The rubber insulation underneath helps prevent against shorts or arcing (however, all components are spaced far enough away from each other to most likely eliminate this from ever being an issue) and the cloth covering gives a more period appropriate look.
All resistors were tested for tolerance and quite a few had to go. Each resistor was replaced by a carbon composition resistor that was checked to be within 10% tolerance of spec.
I did manage to perform an RF alignment and the dial calibration is exceptionally close. Band 3 covers from 4.6mc to 13mc and this includes the two WWV frequencies at 5mc and 10mc. When tuned to either frequency the dial is centered right on the nose of 5mc and 10mc respectively. The only place where there is any issue is when working with the bandspread. For example if you use the bandspread on 40m and calibrate it to be accurate at, say, 7030kc it will be about 10kc off at around 7175kc. I have a feeling this is due to the position of the plates on the bandspread capacitor.
As far as the capabilities of the receiver it is a very nice piece of equipment. It is quite sensitive and doesn't seem to loose too much gain toward the top end of its coverage (15-20mc) which cannot always be said of every receiver. It's reasonably selective for something of its age and price class. You're not going to be able to take a crowded section of the CW band and narrow it down to one signal but the filter does a good job on phone when 75M AM gets crowded during the evening. The filter also does provide a slight peaking effect which is nice when working with CW or a particularly weak voice signal. Audio? Well, it's a single 6V6 so there's always a chance it'll sound good. I have the phones out of the receiver running into the input of a 1950 Webster Electric Ekotape reel to reel player which uses a pair of 6V6's to run an 8" speaker. It sounds very nice indeed with the tone control on the receiver providing excellent function.
It's very nice to finally have found the "right" radio. I'm going to spend a few months enjoying it and then get to work on cleaning the chassis. It just needs a light polish and then I'll be ready to put it into full use and call it done!
Before:
After:
Higher resolution of the "After" photos available here:
http://img600.imageshack.us/img600/6331/dsc01916wd.jpghttp://img577.imageshack.us/img577/3594/dsc01918vd.jpghttp://img809.imageshack.us/img809/8622/dsc01921s.jpg
