Letter Re: Older Technology Radio Receivers

James,
I was glad that a reader mentioned the Hallicrafters S-38 series of radios. I had forgotten to mention that the All American Five (AA5) type of radio was also sold in a multi-iband version by Hallicrafters. These are still often available for under $100 in working condition. I have a Hallicrafters model 5R10A, which is a lot like a [Hallicrafters] S-38D. It’s an AC/DC design like the AA5 radio that can be run on nine or ten car batteries wired in series with no inverter. (In a test, I found that nine fully-charged “12-volt” batteries wired in series provide 113.4 volts DC.) With 50′ of copper wire it picks up stations from everywhere. Just search on eBay for “Hallicrafters S-38.”

While it is obviously useful to listen to foreign shortwave broadcasts, long-range AM listening (DXing) can also provide life-saving information. Canadian AM broadcast stations are easy to receive by those who live in the northern half of the country. Those who live in the south, especially the southeast, part of the US can also find English-speaking foreign stations on their nighttime AM dial. I once lived in the panhandle of Florida and I was easily able, at night, to pick up AM broadcast stations from all around the Caribbean. I can recall in particular one strong English-speaking station in Bonaire, Netherlands Antilles.

After the lights go out, and nearly all modern electronic devices stop working, an old AA5 wired up to car batteries (or better yet, deep-cycle 12-volt batteries) can keep the nighttime listener up to date on such matters as US and foreign troop movements, martial law declarations, fallout patterns, city riots, and highway problems. – ME

JWR Replies: Thanks for the suggestion. To get the maximum life out of tubes and to be kind to capacitors in an AA5, I recommend using slightly low voltage DC (~110 to 115 volts) and when in both AC and DC operation, using an in-rush current limiter. This gives a gentle “soft start” to the components. In common ham radio parlance these are dubbed in-rush filters, but properly they should be termed “In-rush Current Limiters” (ICLs) or “negative temperature coefficient” (NTC) thermistors. One that is typically used by old radio restorers is the CL-90 NTC made by GE Sensing. If you are handy with a soldering iron, it is fairly simple to build your own “In-rush box”, that you can plug in to a surge-protected power strip. The ICL box should have its own its own power switch. This has the advantage of reducing wear and tear on your radio’s combination on/off/volume knob. (This is a part that is likely to fail, typically when the volume potentiometer gets scratchy beyond the point of minor annoyance–the classic “scratchy pot” syndrome.) By leaving your radio’s power switch always in the “on” position and the volume at a comfortable level, and instead controlling the power with your in-rush box, you’ll eliminate most of this wear and tear.