Maybe your MP3 player sounds a bit better than this gentleman’s hi-fi turntable from 60 years ago, but I bet you can’t build yours from scratch, like this guy did.  This one, shown on the cover of the 1957 edition of Radio-TV Experimenter, is entirely homemade, and despite the homemade appearance, probably did sound as good or better than anything on the market at the time, and would probably have sounded good even by today’s standards.

It was actually a phono oscillator, and transmitted the signal through an FM transmitter.  Since the audio quality of the FM signal was better than the recording technology of the day, the fidelity was limited only by the quality of the record.

Sound quality was paramount in every detail.  As is plainly visible, the tone arm is indeed made out of wood.  In particular, the wood is basswood, chosen because it had less mechanical resonance than other woods.  Metal would have been inferior, because of the capacitive effect with the leads running through it.

The pickup was homemade, not as a cost-saving measure, but because the design shown here was superior to the ceramic cartridges then commercially available.  It used a capacitive pickup.  The only commercial component was the sapphire-tiped needle, which was pushed into a rubber plug.  A copper plate was carefully positioned next to the needle to complete the capacitive pickup.

The tone arm was cut with a jigsaw, and the article contained precise instructions for balancing it.

The electronics, probably the easiest part to construct, consisted of a small FM transmitter employing a single 6C4 tube.  The example shown here was to be used for 45 RPM records, but the article noted that by adjusting the size and using an appropriate needle, it could be built for 33 or 78 RPM records.

Seventy years ago this month, the March 1947 issue of Popular Science showed how to put together this portable radio phonograph.  It was by no means deluxe, but it was the epitome of portability.  The magazine noted that in most cases, the “portable” terminology meant only that a handle had been slapped onto the cabinet, and the set was still tethered by the need for electrical current.   But in this case, a crank-up phonograph motor and a one-tube battery powered amplifier meant that it was truly portable.

The electronics consisted of a 1D8GT tube powered by two batteries, a 1.5 volt cell for the filaments, and two 67.5 volt batteries providing 135 volts B+, although it noted that it would work with as little as 90 volts.

The magazine noted that the spring motor should be set to 80, which would result in it running at the desired 78 RPM with a record on the platter.

The radio was simply a crystal set with a fixed crystal, which could be switched in place of the phonograph’s pickup cartridge.  While the radio strength was not great, it would serve to pull in local stations, especially with an external antenna and ground of some sort.

Seventy-five years ago this month, the March 1942 issue of Popular Mechanics carried a construction article for this portable phonograph oscillator.  Mounted in the always available cigar box, the one-tube record player used a 117L7-GT tube to produce a signal that could be tuned in on any nearby radio.

The tone arm could be removed when not in use, and plugged in with two phone tip plugs to hold it in place and make the electrical connection.

Since the phono oscillator only required one tube, and didn’t need an expensive speaker or transformer, they were quite popular for playing records for those who already had a radio.

For use right next to the radio, no external antenna was required.  For a bit more range, a short piece of wire could be added.  The coil inside was wound on a one-inch piece of cardboard, and a variable condenser could be tuned to a blank spot on the dial.

Fifty years ago, sending an audio “letter” by tape was one way to keep in touch with servicemen overseas, but a home tape recorder was still a relatively rarity. So in this ad in the February 1967 issue of Popular Electronics, Radio Shack made an offer to send a tape to a GI anywhere in the world. The sender just had to come into the store, which would allow use of a recorder. They would even supply a free tape, mailer, and postage.

If you think something untoward is happening in this picture from 70 years ago, then you’re wrong.  This radio-phono serviceman is simply making an ordinary service call, and it was important for him to bring the right parts.  This ad from Astatic reminds him that it was always best to use exact manufacturer replacement parts, and that was especially true when it came to phonograph pickup cartridges.

To keep a service call from getting out of hand, the serviceman was advised to carry in his service kit a wide variety of pickups.

The ad appeared in the February 1947 issue of Radio Maintenance.

Seventy-five years ago this month, the December 1941 issue of Radio News carried a detailed description of a sound recording system that, while very sophisticated for its time, was quickly superseded by magnetic recording, first on wire, and then on tape. The magazine described the sound-on-film recording system employed by the Recordgraph, shown above. This machine recorded sound on 35 mm film, but did not involve photography. Instead, the instrument was a sophisticated phonograph, mechanically carving a groove into the film, which did not have any photographic emulsion. Instead of a disc or cylinder, the grooves were cut into the film.

The great advantage of this system was the large amount of material that could be recorded. The market for the system was law enforcement, which could make sound recordings of, for example, a telephone line. The machine could be switched on automatically whenever a phone was off the hook or a radio carrier present. The film ran in a continuous loop at 20 feet per minute. The film could hold 100 tracks, meaning that only 6-1/4 feet of film were necessary for an hour of recording.

A well preserved example of the Recordgraph can be seen at this link.  A similar system, the Tefifon, was commercially produced in Europe, and can be viewed here:

The Recordgraph apparently saw at least some use by law enforcement.  The record from this 1949 New York case includes testimony describing how the device was used for telephone monitoring.

While the sound quality of this system is remarkably good, it was quickly supplanted after the war by magnetic recording, first on steel wire and then on magnetic tape.  The greatest advantage of magnetic recording was that the wire or tape could be erased and re-used indefinitely.

On this date seventy-five years ago, Bates Fabrics, Incorporated, ran this ad in the August 18, 1941, issue of Life Magazine to answer the question that was undoubtedly on everyone’s mind: How were college students decorating their dorm rooms? The company put together a College Board consisting of students from the outstanding universities, and they conducted a survey of over 8000 students.

97% of the respondents believed that an attractive room helped any freshman get off on the right foot. Apparently, 3% believed that a dingy room was the way to go. 86% of the students said that they preferred bedspreads with matching draperies, and a third of them already had them. Fortunately, Bates just happened to sell exactly that: matching bedspreads and draperies, and the Life ad highlighted some of their popular designs.

The Yale men shown above preferred the “Cattle Brands” design, which, according to the ad, proved an overwhelming favorite in men’s colleges. And as you can see, these Yale men also had a radio in their dorm room. The radio sitting on the desk appears to be a Zenith model 5-G-401.

This radio was Zenith’s very first portable, sporting a lineup of 1A7, 1N5, 1H5, and 1A5, in addition to a 117Z6 rectifier. The set retailed for $44.95, and could operate off either AC power, as it probably did in the Yale dorm room, or with batteries.

On the Left Coast, the co-eds shown here preferred a “gay, sun-country pattern on homespun ground” for their bedspread and drapes. They apparently preferred to listen to phonograph records on what appears to be a wind-up non-electronic phonograph.

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