VE7SL RADIO NOTEBOOK

The HALLICRAFTERS S-40A



S-40 DIAL


THE HALLICRAFTERS S-40A

Hallicrafters produced the S-40A's from 1947 to 1949. The "A" model followed the original S-40's one year run begun in 1946. It was to be the start of a number of S-40 'look-alike' models from the Hallicrafters plant, which over the next eight years proved to be some of the companies best-ever sellers. The mesmerizing back-lit dials were hard to resist and the receivers delivered good performance at an attractive price.

S-40 AD


The early S-40s' sold for $79.50 in 1946 and like the S-38 'handbook' ads, far too much time was spent at the local library drooling over the DX opportunities that owning an S-40 might bring. When production stopped in 1954 I was just seven years old and didn't see my first S-40 until four years later. It was love at first sight but I was never able to afford one as a kid. I have since made up for lost time and have, at last count, eight variants of the S-40 to bring back to life!

The first S-40A restoration began life in the Toronto Rogers-Majestic assembly plant. It appears that Hallicrafters had contracted the R-M folks to assemble and distribute the radios in Canada for the growing Canadian market.

S-40 ID

Although the ID tag identifies this as an S-40, this 12,733 unit is clearly an S-40A as shown by the cabinet labelling as well as by circuit changes. Slowly bringing the unit up on a variac revealed a working radio with few problems. In fact the only restoration required would be a thorough cleaning, a re-capping of all paper condensers and a repair of the non-working BFO circuit.

CHASSIS LABELS
As shown in the left picture, the chassis had some rust spots as well as a thick layer of oily dust, often found on 50 year old steel chassis. After locating the parts to be removed, I like to label them, as shown in the right picture. Once all of the parts in a given area have been marked, part replacement can begin.

NEW CAPS

All of the paper / wax capacitors were removed and replaced with new 600V units. All of my high voltage capacitors are purchased from "Just Radios" in Canada (see link at bottom of page). Surprisingly, all of the removed capacitors measured well within their stated tolerance. I am always amazed at the small size of new capacitors compared with the ones made in the '40s.

A close inspection of the BFO circuit indicated a previous but unsuccessful repair attempt. As the Hallicrafter's engineers often liked to do in BFO circuits, a gimmick capacitor consisting of two short twisted wires was used to couple the BFO signal into the detector. This particular S-40 had one of the two wires soldered to the correct tube pin but the other one (to twist together with) was not to be found. Examining the tube pin showed no indication that there ever had been a second wire as the solder was smooth, original and undisturbed. The one wire that was installed showed no indication of ever being twisted with another. It is likely that the BFO circuit on radio 12,733 never did work, right off the Rogers Majestic assembly line. Perhaps it was wired or tested very late on a Friday afternoon, back in 1947!

CLEANED UP

Once recapping was complete, a thorough cleaning of the chassis, knobs and dials followed. The chassis was washed with a warm water and soap solution and flushed several times. All of the rust spots were coated with rust remover (Naval Jelly) applied with a Q-tip. A light polishing with extra-fine steel wool removed all traces of rust and produced a nice shine to the old chassis. Following this, a light coating of WD-40 was applied to the chassis to help inhibit rusting. After spot testing, the plastic dials were washed, again with warm soap and water. The knobs were sprayed with "Spray & Clean" and allowed to soak before using an old toothbrush to scrub fifty years of grime from their fine grooves. They were then lightly polished on a buffing wheel until their original lustre was restored. Before mounting the dials and the front panel, all switches and pots were given a shot of control cleaner and all bearings and shafts were either greased or oiled. The front panel was then given a thorough cleaning, also with "Spray and Clean", after spot testing.

FINISHED

After a quick alignment, including the BFO, my first S-40 restoration was complete. One down, seven to go!


HELPFUL LINKS

JUST RADIOS  - Capacitors and schematics for tube radios. A great source of high quality capacitors in Canada as well as great prices. Highly recommended!

BOATANCHOR MANUALS  - Find the manuals and schematics online for a ton of radios!

ADRIAN'S TUBE RADIOS  - Find the S-40 link on Adrian's home page.

RESTORING THE S-40  - Jeff Miller's S-40 project...lots of good stuff.

THE S-38 GUY  - Brian Ripley's (K8BR) fantastic S-38 site.

NOSTALGIA AIR  - Find the schematic for your boatanchor here!

DXing. COM's RECEIVER PAGE  - Photos and specs for the S-38 and the S-40.

LA5KI's BA SITE  - Top and bottom photos "under the hood" for the S-40.

HALLIGAN'S HALLICRAFTERS INTERNATIONAL  - W9WZE's 'must-see' Hallicrafters site!

RADIO BOATANCHOR PARTS  - Find that special part here!

PHIL'S OLD RADIOS  - A wonderful description of Phil Nelson's S-40B restoration. A must read!!



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