Hallicrafters S-40 - The Good, the Bad and the Ugly

The Hallicrafters S-40 is a classic MW/SW tube radio from the late 1940's. Some time ago, I resurrected the exterior of the radio from its pathetic state, and recently had a go at the alignment procedure. In this video, I take you through the controls, the woes of alignment and its performance.

[@cw2gtc]

Nostalgia has a valid home in ham radio.

[@user-dh2vk3ye2w]

I was given a Hallicrafters SX-99 that, cosmetically, is in good shape. I have not yet plugged it in to test it but will re-cap first. You've given me useful information on moving forward with the unit. Your videos are top notch so please keep them coming.

[@davidwarner1459]

My Dad bought me one of these when I was at secondary school - about 1966. The problem here in the UK was that my set was purely US voltage - so had to use an auto-transformer to step down the supply from 240v. It gave me a lot of fun listening to Voice of America (including "This is the Voice of America in Special English") also radio Moscow, Prague, Tirana (Albania - used to give the Chinese spin on the news, mainly Vietnam, American Paper Tigers etc) Not sure I agree with your comment on SSB. But mostly UK radio amateurs used SSB on 80 metre band and it was very stable. I seldom got any amateur transmissions on 15m or 10m bands. I see you also got nothing on 10m. Possibly there was a problem on the highest frequency range. I tried "upgrading" the set by replacing the mains supply transformer with a UK type, fitting silicon rectifiers and some other mods. My brother has it now, but to restore it to pristine condition like yours would be a major project. 😀

[@wordsmith_bob7222]

I bought an S-40B with some good potential off eBay about 10 or 12 years ago and spent some time recapping, aligning and generally getting it into what I consider excellent condition. I wound up replacing the toggle switches, one of which was broken. Amazingly, these were still available in their original form. Alignment is an art form. I have spent countless hours aligning everything from S-38s to Hammarlund SP-600s (48 adjustments in the RF section alone). My feeling is that dials were designed using a prototype chassis. Given the vagaries of parts control, they just don’t fit all the production units very well. Oscillator points should be adjusted about 10- to 20-percent in from each end of the band to get the best fit throughout the band. The frequencies specified in the alignment instructions should serve only as starting points. Once the main tuning was aligned as well as possible, I developed frequency graphs on the bandspread logging scale. An outboard crystal calibrator is helpful for this. I restrung the tuning and bandspread dials using 50-lb test, microfilament, braided fishing line. This is much better than regular dial cord, as it provides exceptionally smooth tuning with minimal slack or backlash. The bandspread on the S-40B lacks the nice flywheel present on the original S-40. My unit is also setup to plugin an optional outboard Heathkit GD-125 Q-multiplier. This improves selectivity. Many years ago, a ham buddy taught me how to tune single sideband using combinations of the sensitivity and pitch controls, and CW and AVC on/off switches. For tuning SSB as well as narrow bandwidths produced by the Q-multiplier, the main drawback of these old radios is stability. They drift significantly during warmup, and somewhat less thereafter. All things considered, the S-40, S-40A and S-40B were excellent cost-performance tradeoff options for hams and SWLs 70 years ago. Yours, sir, is a beauty and must give you lasting satisfaction in its restoration.

[@radiotopics1874]

Great comments. Thanks!

[@johnkleinbauer4424]

Set the slug in the OSC coil on the low end of the dial. The reset the top of the band using the trim cap. Go back and fourth a few times. I have several National NC57 units. One does not have slugs in the coils so there is no way to fix the tracking. Do the Slug in the Coil of the OSC first. (AM) Broadcast Then do the Cap. If you reverse the operation it won't work.

[@willthecat163]

Lots of S-40 turn up... at least around here. (noting rare for sure... and not a great radio either.) I think it's mostly because of the Hallicrafters name. (for sure, there's an S-40, in more than a few basements, as ballast, to hold the floor down.) As for decal kits (or even cap kits) ... I think they sell a fair amount of them. It's not a rare receiver at all.

[@willthecat163]

If you like old, heavy, and big radios... that supposedly look good...then you might like these old SX series Hallicrafters receivers... especially, if you think mass = class. Ok... I guess... for free... if you want something to hold the basement floor down. Otherwise... except for perhaps the sound (if that's your thing) any modern receiver will kill them.