Vintage Audio: Sony AIR-7 Aviation Band Synthesized Receiver

This Found in the Attic installment is an ‘80s flashback, even though it doesn't involve After the Fire, Blondie, or the Psychedelic Furs. Our subject is a 1985 Sony AIR-7, one of the earlier scanner receivers using frequency synthesis. From the name of this receiver, it's easy to surmise that it was designed to monitor the aviation bands, although it did quite a bit more.

Topics: Vintage Electronics

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.

Topics: Vintage Electronics, Vintage Audio Technology, Broadcast History

Vintage Audio: Fly with an Edo-Aire ADF Receiver

Found in the Attic columns regularly seek out forgotten or unusual types of AM receivers, be they farm radios, high-fidelity AM, unlikely frequency coverage, or novelty types. If you're totally stumped by the picture of this device, don't feel too bad. Unless you've had a pilot's license and been flying private aircraft for the past thirty years, you'd have no reason to encounter one of these receivers. This installment follows on the Sony AIR-7, and is our second aviation-related entry. The Edo-Aire R-556 E ADF (Automatic Direction Receiver) is typical of radio navigation aids that were in virtually all private aircraft before the advent of GPS receivers.

Topics: Vintage Electronics, Vintage Technology, Broadcast History

Vintage Audio: Atwater Kent Model 84

From the dawn of broadcasting in the early1920s through the mid-1930s, the name Atwater Kent was synonymous with top-quality radios. Their commitment to excellence, in both cabinet construction and electronic assembly, is one of the reasons so many of their sets are still around and in working condition. There are several A-Ks in the attic, but none have been featured in FitA. Until now. This month, the 1932 Model 84 will be showcased, along with a history of the man and his company.

Topics: Vintage Radio Technology, Vintage Electronics, Radio History

Vintage Audio: Heath GR-81 Economy Short Wave Radio

An ancient Chinese proverb says, “The longest journey begins with the first step.” And so it is with building Heathkits. Over the years, I've assembled countless Heathkit projects, most for personal use, some for the electronics workbench at college media centers and radio stations, and a few as gifts. But you never forget your very first one. When I made my most recent trip to the attic, I came down with numero uno, my first electronics kit, a Heath GR-81 economy short wave radio. This three-tube, four-band receiver covered 140 Khz to 18 Mhz. The GR-81 had a long production run, from 1961-1972. List price in the 1967 catalog was $23.50. The estimated time for completion was about six hours.

Topics: Vintage Radio Technology, Vintage Electronics

Vintage Audio: Western Electric Gear

As an electronics geek coming of age in the 1970s, my need for components and other gear often outstripped my meager budget. Between construction projects in Popular Electronics and restoration of surplus grab gear, the revenue from the allowance and part-time job wasn't enough.

Fortunately, help was at hand. With the rapid obsolescence of equipment and a thriving economy, it was often simpler for both consumers and companies to replace than repair. Picking up discarded TVs and stereos during the town's annual spring cleanup yielded a wealth of components. Occasionally, colleges got overwhelmed with components from surplus grabs and would pass some along to deserving high school students.

Topics: Vintage Electronics

Vintage Audio: Detrola Model 276 “Super Pee Wee” Radio

Long before the Motor City was known as “Motown” it was simply called Detroit. And while it was the hub of the automotive industry, it was also the home base for lots of other manufacturing concerns, including the 6^th largest supplier of radios in the USA. This Found in the Attic examines the Detrola model 276 “Super Pee Wee” radio, discusses the history of the company, and talks about why private labelling was such a big deal for some manufacturers.

Topics: Vintage Electronics

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.

Topics: Vintage Electronics, Vintage Audio Technology

Vintage Audio: VOMs and VTVMs

Accurate measurements of voltage, current and resistance have been an essential part of electronics troubleshooting since the beginning. Early repairmen used pocket watch meters, which were the topic of an earlier Found in the Attic. Using different meters for voltage and current, as well as for different voltage ranges, was pretty inconvenient. Soon, with the addition of rotary switches, and 'A' battery and meter multiplier resistors, the VOM, or volt-ohm milliammeter evolved. It was a giant leap forward for convenience, but left us with one of the limiting factors of pocket watch meters, namely that the internal resistance of the meter loaded the circuit under test, resulting in inaccuracies.

Topics: Vintage Electronics

Vintage Audio: Lafayette LT-81 FM Stereo Tuner

The 1960s were a transitional time for consumer electronics. The market for quality equipment was dominated mostly by American and German companies. By the mid-1970s, Sony and Panasonic were the names to watch. It didn't happen overnight. The earliest Japanese imports were laughable examples of shoddy workmanship and design. But they quickly learned from their mistakes, and began to roll out quality products rather quickly. In the end, American companies either went out of business or changed directions and went into things like government contracts.

Topics: Vintage Electronics