Magnetic Tape and the Emergence of High-Fidelity Recording
In the earliest days of sound recording (late 1880s to 1926), all recordings were made acoustically. That is to say, a recording machine with a large horn with a needle on the other end was set before an orchestra and the vibrations from the needle would “draw” a pattern on a spinning wax cylinder (or later flat disc). If a vocalist was called upon to sing, they would stand before the horn and sing right into it.
Read MoreTopics: Vintage Electronics, Vintage Audio Technology, Broadcast History
Vintage Audio: Shure M67 Mic Mixer
Some pieces of broadcast equipment are destined to become classics. The Otari MX5050, Gates Sta-Level and Spotmaster 500 cart machines come to mind. All were rugged, easy to service, and affordable. And so is our current attic discovery, the Shure M67 microphone mixer.
The story begins almost 50 years ago, in 1968 when the M67 was introduced. Production continued through 1987. In 1968, many stations were still using portable mixers with vacuum tubes, so an upgrade to solid state was a plus. One of the early footnotes in the history of the M67 was its use in the recording of Woodstock in 1969.
Read MoreTopics: Vintage Audio Technology
Vintage Audio: Singer TTG-3 Two-Tone Audio Generator
Many of the items featured in Found in the Attic are familiar staples of the broadcast, test equipment or consumer electronics industries. But sometimes we feature the obscure. This is one of those times, as we revisit a college surplus grab from the 1970s, and look at the Singer Two-Tone Audio Generator Model TTG-3.
Part of what makes this device obscure is that it wasn't designed as a stand-alone piece of test equipment. Rather, it was a plug-in component of the Singer Panoramic Model SSB-50 Single Sideband Analyzer System. Since it is a two-tone generator, it could be used for single or two-tone modulation of single-sideband transmitters, intermod distortion tests, harmonic distortion tests, and general troubleshooting.
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Vintage Audio: Hallicrafters S-20 'Sky Champion' receiver
This installment of Found in the Attic examines the Hallicrafters S-20 'Sky Champion' receiver. The 'Sky Champion' line was the company's' mid-priced communications receiver. Introduced in 1938, the S-20 was replaced by the S-20R in 1939. Since it was in production for less than a year, these receivers are somewhat rare.
There are several differences between the S-20 and S-20R. The S-20 primarily used tubes with grid caps, while the later S-20R used newer replacements. Tube lineup for the S-20 includes: 6K7, RF stage; 6L7, 1st detector-mixer; 6J5, HF osc; 6K7, IF amp; 6Q7, 2nd detector-AVC-1st audio stage; 6F6, audio out; 6J5, BFO and 80, rectifier.
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