Hallicrafters Model S-38 Communications Receiver (1946)

            Adding an S-Meter

One of the most popular shortwave radios ever made, the charming Hallicrafters S-38 introduced many thousands of people to shortwave and CW listening. It appeared in 1946, immediately after the World War II consumer radio hiatus, and was priced at only $47.50, making it the entry-level receiver for the Hallicrafters line.

This advertisement from Radio News magazine of 1947 shows the S-38 along with two more expensive Hallicrafters sets.

Description

Using six tubes, the S-38 is a transformerless AC/DC radio with a metal cabinet and integrated speaker. Its compact size and low cost made it very attractive to radio-hungry consumers in the postwar years. Following the original S-38 were models S-38A through S-38E, remaining in production until 1961.

Despite its simplicity, the S-38 is a "hot" radio, offering good sensitivity. Like more expensive shortwave receivers, it has a separate bandspread tuner, automatic noise limiter (ANL), and beat frequency oscillator (BFO) for CW listening. It covers frequencies from .54 Mhz to 32 Mhz in four bands. Many collectors consider S-38 the most desirable model in this line, since later models lack the BFO feature.

With distinctive semi-circular dials, the S-38 through S-38C models are very recognizable. Models S-38 through S-38B are black, some with a wrinkle finish. The S-38C has gray hammertone paint. The S-38D and S-38E have a rectangular dial but have the same features as earlier models. The S-38E was offered in beige and mahogany as well as gray.

Here is the lineup of the receiver's tubes:

Tube Type Function
V1 12SA7GT Converter
V2 12SA7GT IF amplifier
V3 12SQ7GT Detector/AVC/AF
V4 12SQ7GT BFO/ANL
V5 35L6GT Audio output
V6 35Z5GT Rectifier

From a collecting standpoint, the S-38 line is a good way to get started with "boatanchors." Manufactured in great numbers for more than a decade, they are still plentiful, and you can often find a good one for less than $50. I paid about $45 for mine.

A nice feature of the S-38 is its ability to flip quickly across the bands to see what stations are on the air. But it does lack a couple of features that I've grown to appreciate in my fancier boatanchors: an S-meter and an antenna trimmer. An S-meter indicates the strength of the incoming signal and a trimmer matches the impedance of your antenna, both aids to accurately tuning weak signals.

A friend recently sent me some Hallicrafters literature that explains how to add an S-meter to the S-38 and several other Hallicrafters models. Our resident engineer, Walter Heskes, tried out the project, and provided an updated schematic. Check out our S-38 S-meter page for construction details.

First Look

My S-38 was complete but rough-looking when purchased. The following photo shows the set before restoration.

As you can see, the black cabinet was splattered with paint specks in two different colors (mostly white, but some red). Based on the paint, and the amount of dirt found inside, I suspect that this was somebody's shop radio. If you look closely, you can see a large blob of dust in the middle of the speaker. Although a top-mounted speaker conserves space, it also serves as a wonderful dust-catcher!

Electronic Restoration

The radio had not been used for some time; most of the slide switches on the front were frozen solid. The first thing I did after removing the chassis from the case was to spray DeOxit inside all the controls, freeing them up and cleaning out accumulated gunk.

After I slowly brought up the power on an autotransformer, the radio did play, but the volume was very weak. Powering it down, I proceeded to replace the old paper capacitors. (See Replacing Capacitors in Old Radios.) I also cleaned the entire chassis and tested the tubes, all of which were good.

As boatanchors go, this is an easy set to work on. The underside of the chassis is uncluttered and there are only about ten paper capacitors to replace.

After the recapping was finished, the radio played quite well, but the volume was still weak. Looking for the source of the problem, I tested the voltages of each tube, comparing them to the values given in the schematic. I also tested the volume control's resistance. Everything checked out OK, so I tried another shot of DeOxit inside the volume control.

To my delight, the set woke up and played with plenty of volume. Some times, one cleaning is not enough!

Not much work had been done on the electronics before I got this set. The only previous service, apart from replacing some tubes, was to replace the filter capacitor in the power supply. Since the radio played without any hum, and had no power-supply problems, I left that filter capacitor in place. The next photo shows the underside of the chassis after restoration.

Cosmetic Restoration

That left the cabinet, which looked pretty daunting at first. Soap and water did nothing to remove the hundreds of paint specks, and scraping them off one by one was not an appealing prospect. After a little investigation, I found a product called Goof-Off 2, which claimed to remove latex paint specks. Available in a spray bottle, this worked very well.

The trick is to spray on the cleaner and let it soak for a few minutes, before rubbing the paint specks with a soft rag. Within ten or fifteen minutes, the cabinet was completely clean. Unlike some solvent-based cleaners, Goof-Off 2 is not stinky. That's a real bonus when you're working indoors.

Use care when cleaning cabinets with painted lettering. Scraping or rubbing the lettering too hard may damage it, no matter what sort of cleaner you use.

The upper left corner of the cabinet also had a rust spot about the size of your thumb. To remove the rust, I carefully applied some naval jelly with a Q-tip swab and let it work for a few minutes. Then I wiped it off and cleaned that corner again with Goof-Off 2. The paint on that corner was worn completely away, so this treatment left a bare metal spot on the corner.

I haven't decided whether to repaint that bare spot. Some paint "touch-ups" end up looking worse than the boo-boo that you're trying to cover up! In present condition, the radio doesn't look like a museum piece, but it's pretty presentable. And it performs like a new radio.

Safety Note: Like all "AC/DC" type radios, the S-38 presents the danger of electric shock if you touch its chassis while plugged in. To minimize the risk, you should always operate the radio from an isolation transformer rather than plugging it directly into the wall. Isolation transformers are available from Antique Electronic Supply and many other sources.

I own several other Hallicrafters radios. Click the Communications link at the top of this page to read about them.

About one year after finding this S-38, I ran across another one in a thrift store. The cabinet looked rough, but the price was right, so I brought it home. It performed very well after routine maintenance. Perhaps I'll put it in one of my sons' bedrooms to get them interested in shortwave listening. (I won't forget to provide an isolation transformer to ensure safe operation!)

©1995-2014 Philip I. Nelson, all rights reserved