Tag Archives: boat anchors

SWLing with heavy metal: my Signal Corps BC-348-Q

I write a great deal about DSP portables, SDRs, and modern ham radio transceivers, but truth be known, my passion is for older rigs–ahem, much older–the antique “boat anchors” of the radio world.

Tuesday afternoon, I had a rather involved soldering project to do on behalf of my organization, Ears To Our World. While I worked, I decided to fire up my Signal Corps BC-348-Q to hear what was on the air. I promptly discovered Radio Exterior de España on 17,850 kHz–starting with their interval signal; REE, care of my BC-348-Q, kept me company while I soldered almost three hundred connections.

The BC-348-Q frequency dial (Click to enlarge)

I listen to my BC-348-Q nearly every week. Usually, she’s tuned to 9,580 kHz for my morning dose of Radio Australia. In the winter, the ‘348’s tubes keep my little radio room a little warmer than the rest of my house. In the summer–well, I just sweat a little more.

I love this radio, and my other “boat anchors,” because when I listen to these rigs I can’t help but hear the past. I wonder about the others who have listened to the same radio, and what was happening in their lives as they listened…

The BC-348 series, for example, is well-known for its use in WWII allied bombers–these rigs were mounted in the likes of the B-17, B-24, B25, and others of the era. Indeed, mine still has the original clips on the base that anchored it to the radio operator’s onboard work table. The ‘348 was used as a long-distance liaison receiver during WWII.

The B-17 radio operator’s position (Source: AZ Commemorative Air Force Base)

The BC-348 series was built with simplicity, functionality, and serviceability in mind. It was built to withstand life on a B-17 bomber–the extreme vibration on start up, the extremely low temps in the upper atmosphere; it could be serviced by the radio operator in flight, if necessary. Its controls are simple, bare-bones, even. The tuning knob and analog dial are beautifully engineered and precise.

The ‘348 has a power switch, volume control (switchable from auto to manual gain), crystal filter, CW switch, beat frequency control, tuning knob, and a band switch (located just below the dial). The antenna and ground terminals are mounted on the front of the radio for easy accessibility. All controls are spaced so that the radio operator could use the ‘348 even while wearing thick cold-weather gloves.

You can’t do any medium wave DXing on the ‘348, however: this receiver was intentionally designed with the medium wave band omitted. Evidently, Uncle Sam wanted radio ops to be focused on communications instead of entertainment (but that’s okay; the government also made morale radios for the latter).

When I go to the Dayton Hamvention–or any hamfest, for that matter–it’s radios like the BC-348-Q I seek. Tube/valve radios sometimes lack the sensitivity and (digital) accuracy of modern tabletop shortwave receivers, but they make up for this in audio fidelity. As long as you have a properly-matched speaker, the sound can be…nothing short of amazing. Even though the ‘348 was never designed for robust audio, it still sounds richer and fuller than most modern tabletop radios. The sound is so warm it literally glows. Moreover, I’d be willing to wager that there are few modern receivers that can stand the test of time like these rigs.

If you buy one of these old beauties, you must be ready to service them; inevitably, a capacitor or tube will fail in time. But they just…keep…going.

I’m very much in debt to my good friend and radio elmer, Charlie (W4MEC) who kindly teaches me everything I need to know about these great rigs. He’s exceedingly patient, and that counts for much, as I’m not by nature technically inclined. But I do enjoy learning about these radios and how to service them; the romance of their history draws me in, and I simply can’t get enough.

Note: It’s important to work with a knowledgeable elmer/mentor or a professional repair technician when servicing these boat anchors, because, unlike with our modern radios, their high voltages can severely injure (or even kill) you if you don’t know exactly what you’re doing inside the chassis. This is repair work for the professional.

My BC-348-Q turns 71 this year–and I’m sure it has at least that many more years to go. I know that I’ll give it as much TLC as it can take. We must keep these still functioning pieces of history on the air.

If you, too, have boat anchors or antique radios alongside your modern rigs, please comment! I’d love to learn about your favorites. In other words, what heavy metal is in your shack?

Resources:

Search for a used BC-348:
More info on the BC-348-Q

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WBCQ’s “new” monitor: a Navy model REH

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(Source: WBCQ Facebook Page)

Check out this Navy receiver model REH, that the good folks at WBCQ The Planet have electrically restored. The REH was an “amenities” receiver used by the United States Navy in World War II for troop entertainment. WBCQ, however, has given this one a second life as a station monitor.

No wonder that glowing green magic eye is so bright–it’s tuned to a broadcast that’s being transmitted from WBCQ’s back yard in Monticello, Maine! WBCQ says it “sounds great.” No doubt!

Thanks to WBCQ for sharing this on their Facebook page!

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Try that with an iPhone!

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With the help and guidance of my good friend Charlie, we just repaired and aligned this BC-348-Q receiver. BC-348s were built to withstand the extreme temperatures (-60F) and vibrations on board the B-17 and other bombers, where they were used extensively in World War II. I picked this beauty up at the 2012 Dayton Hamvention for $40.

Next year, this radio will be 70 years old.

This morning, I have it tuned to Radio Australia’s Saturday Night Country on 11,660 kHz shortwave. It’s “connecting” to a wireless network over 9,800 miles away and producing beautiful, warm audio.

Try that with an iPhone.

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The Ten-Tec Hamfest–and my new (vintage) LS-166/U military loudspeaker

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My only purchase at the Ten-Tec hamfest flea market this year, the LS-166/U military loudspeaker

This past weekend was the Ten-Tec Hamfest, which is held each year at the Ten-Tec factory in Sevierville, Tennessee, USA. I’m particularly fortunate in that I live within a few hour’s drive of the factory, so I make it a point to attend the Hamfest each year.

Hamfests, for those of you not familiar with them, are basically flea markets or swap-meets for amateur radio operators and radio enthusiasts of all stripes. It’s a place to reunite with hobbyist friends and to trade, sell, or purchase new or used radio equipment. The Ten-Tec Hamfest is free, draws a sizable crowd, and what’s more, attendees get the opportunity to try out Ten-Tec radio equipment and tour the factory where their products are made. The Hamfest also coincides with the annual SEDCO DXer/Contester Conference, which is held in the same town, and begins just as the Hamfest winds down.

This year, I had not intended to buy anything. Still, I’m pleased to admit I bought only one item…

The LS-166/U loudspeaker is built like no other–it’s even gun blast resistant! Its rigid cone is well protected by thick metal screen and mesh.

My purchase: an LS-166/U loudspeaker. This small speaker has been used extensively in military operations around the world. It’s built like a tank, was perhaps mounted in some, but used primarily used in Jeeps, trucks, and on portable radio packs. The case is made of metal and extremely durable. The two watt speaker has a permanent magnet. It is also fungus, gunblast, and immersion resistant: if you drop this speaker, you don’t need to worry about damaging it–rather, you may need to worry about the floor (or your foot).

Side view of the LS-166/U: though heavy, its dimensions are only 4.75 x 4.75 x 3″.

The really cool thing about this speaker is that it contains an audio transformer that–via a switch on the side–will allow you to chose between a 600 ohm primary and 8 ohm secondary impedance. The speaker sounds crystal clear, even though mine has obviously received extensive usage. That’s the great thing about military gear–it was designed for functionality, often over-engineered, and certainly built to last!

The LS-166/U is not for listening to music–it was designed primarily for radios that require a high impedance load, and for voice audio clarity. If you’re receiving orders over the radio from your commander, the LS-166/U will punch through the noise from your vehicle and surroundings. It sounds “tinny” if used to listen to shortwave broadcasters, but is actually quite effective when used to listen to amateur radio transmissions and morse code. The 300 Hz to 7 kHz frequency response is ideal for this type of application.

The schematic is printed on the inside of this back plate, which is easily removed with a plain head screw driver

The first rig I hooked up the LS-166/U to was my Hammarlund SP-600, which has a 600 ohm output. Though I know I can hook up a larger, more responsive speaker for better fidelity, there is something rewarding about hearing a speaker that has seen so much service being used once again, and still playing as if new.

As you can see from the photo below, mine lacks the knob on the side of the case. I’ll be looking for one of these at the next Hamfest–or may just order one from Fair Radio.

If you happen to locate the LS-166/U loudspeaker at your local Hamfest, grab one! There are a lot of them floating around and they’re usually quite affordable–typically between $10-20 US (more if mint). I was lucky to pick mine up for $4. Not only is it an affordable piece of military radio history, but I think it would make an excellent external speaker for amateur radio use during outdoor events like Field Day. Indeed, I think this speaker will weather any radio challenge!

So, what else did I see at the Ten-Tec Hamfest this year? Quite a few classic receivers. Though I didn’t take many photos, I did snap a few gems…

Photos

This aluminum radio speaker reminds me of the external speakers found on radios in the early 1900s. The seller had made a custom wooden base for this one (click to enlarge)

Heathkits, in near-mint condition (click to enlarge)

An antique Marti receiver, the first of its kind I’ve ever seen (click to enlarge)

A close-up of the Marti’s beautiful dials (click to enlarge)

The Kennedy 281 (click to enlarge)

If you visit the Ten-Tec factory, tour their radio museum, housing nearly every radio Ten-Tec has produced. One example is the SP-325 (on bottom) a shortwave receiver which once served the US government as a training radio. They’re fairly rare, but can be found occasionally on eBay. (click to enlarge)

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Gizmodo: “shortwave radio deserves a place of prominence in the home of any audiophile”

Jeffrey revives an old friend, his Hallicrafters SX-110

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SWLing Post reader, Jeffrey Fritz, sent me the following message and has kindly allowed me to share it with other readers. I’mthoroughly inspired!

Bottoms up! Considering how old this receiver is, the chassis bottom (still with the original power cord) really is clean. This is how the bottom of the chassis looked when I removed the receiver from its metal cabinet.

As a teenager in the 1960s I spent a considerable amount of time SWLing on a Hallicrafters SX-110 communications receiver. I collected QSL cards from all over the world and loved being an SWL.

The SX-110 was purchased on 9 September 1961 from Gem Electronics in Farmingdale, Long Island, New York. My parents bought it for me, probably after a great deal of whining and cajoling on my part. Although much of my gear has long since been sent to some landfill by my parents, like my precious Lionel trains, I would not allow them to trash the SX-110.

The top of the chassis, however, is not as clean. Some elbow grease will clearly be required.

The radio has been sitting in one basement or another, unused for the better part of 30 years.

Yesterday I decided to try bringing the radio back to life. Restoring this kind old receiver was a labor of love. The receiver was carefully looked over and tested with a VOM for bad components and the top of the chassis cleaned as best I could. The bottom was pristine. I just needed to clean out a few cobwebs and replace the power cord.

All eight tubes. Note the three original Hallicrafters tubes with the orange labeling.

After being cleaned up and several components tested, the SX-110 was slowly brought back to life on a Variac. I started at 10 volts AC and slowly increased the voltage every ten minutes by another ten volts. When I got to about 90 VAC, I could hear static and distorted audio coming out of the speaker. It was a good sign that the radio would come back to full operation once I reached the normal 110 VAC input–and that is exactly what occurred.

I am happy to report that, with a little patience and love (and a good cleaning) –and with three of the original Hallicrafters tubes still in place, my trusty old Hallicrafters SX-110 shortwave receiver is happily working today. I have it connected to its original Hallicrafters R-47 3.3 ohm speaker.

The top chassis is cleaned as much as possible. Not perfect, but a little cleaner than before. We now have about 110 volts applied through the Variac. No smoke but we do have lights!

Yesterday evening I listened to Radio Taiwan, Radio China International, Radio Havana Cuba, The Voice of Turkey and The Voice of Russia. The audio quality was rather decent without a hint of AC hum. The radio is probably due for a good alignment. I am running the radio on the Variac set at 110 volts AC and will probably keep it on the Variac because the AC voltages today in the U.S. are significantly higher than they were in 1961.

Even the XYL thinks that the radio sounds terrific! What better recommendation can there be for this old, vintage receiver?

73, Jeffrey Fritz, WB1AAL

The restored SX-110 sitting on the bookshelf in the shack. No one would mistake this for a new receiver, but it works just fine.

PS–Jeffrey also mentioned to me: “If you look closely at the chassis stamp photo of the SX-110, you can see a stamp that reads ‘199117 C.’ This is the manufacture date of the receiver. The fourth digit is the year, and the fifth and sixth digits are the week of the year. So, 199117 is the 17th week of 1961 or the week of 23 April 1961.”

Very interesting. Now I need to examine a few of my own Hallicrafters receivers…