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Blog Central

Found in the Attic: Heathkit GR-81 Economy Short Wave Radio

Posted by Tom Vernon on Jan 9, 2017 10:00:00 AM

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.

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Topics: Vintage Radio Technology, Vintage Electronics

Found in the Attic: Western Electric gear, or... Dumpster Diving at Ma Bell

Posted by Tom Vernon on Dec 21, 2016 9:49:00 AM

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.

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Topics: Vintage Electronics

Found in the Attic: Detrola Model 276 “Super Pee Wee” Radio

Posted by Tom Vernon on Dec 7, 2016 9:29:00 AM

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 6th 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.

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Topics: Vintage Electronics

Found in the Attic: GE Superadio III

Posted by Tom Vernon on Nov 1, 2016 9:47:00 AM

Is it too soon for a Found in the Attic ‘90s flashback? Before you answer yes, think about how much the mass media and technology have changed over the past 20 years. In the early 90s, the Internet hadn't yet happened, and there was no streaming media. Radio was still an AM-FM thing. In this world, specialty receivers were not uncommon. A few people were still interested in long-distance AM listening (DXing), and to meet that need, the GE Superadio series was offered. This Found in the Attic examines that series, and the Superadio III in particular.

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Topics: Vintage Electronics

Found in the Attic: Panasonic 8-Track Player

Posted by Tom Vernon on Oct 17, 2016 9:20:00 AM

Break out those Merle Haggard tapes, it's time to go 8-trackin'. During this trip to the attic, we'll revisit those 70s machines that go kachunk, 8-track players. We'll discover the history of this format, peek inside a Panasonic RS-804US 8-track player, and visit with 'Trackers', who keep everything 8-track alive.

It all began with a desire for freedom of choice. Back in the early 1960s, a few people had begun to resent the limited choices they had for music while driving. AM radio was predominately Top-40, with a very limited playlist. FM radio was in its infancy, and most car radios were AM only. Bottom line, if you lived outside urban areas, your options for automotive listening were limited. This restriction was especially felt by truck drivers, who spent countless hours on the road.

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Topics: Vintage Electronics

Found in the Attic: Singer TTG-3 Two-Tone Audio Generator

Posted by Tom Vernon on Sep 7, 2016 1:15:00 PM

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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Topics: Vintage Electronics, Vintage Audio Technology

Found in the Attic: VOMs and VTVMs

Posted by Tom Vernon on Aug 25, 2016 4:11:00 PM

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.

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Topics: Vintage Electronics

Found in the Attic: Lafayette LT-81 FM Stereo Tuner

Posted by Tom Vernon on Aug 22, 2016 10:53:00 AM

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.

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Topics: Vintage Electronics

Found in the Attic: Wilkinson Transmitter Extension Meter

Posted by Tom Vernon on Aug 4, 2016 3:13:00 PM

This chapter of Found in the Attic explores a forgotten chapter in the history of broadcast remote control technology, transmitter extension meter panels.

In the earliest days of radio, the Commission required all operating transmitter sites to be manned by someone with a First Class FCC license. That person was required to take meter readings every 30 minutes, maintain the transmitter log, and make repairs, or switch to a backup in the event of failures.

As technology evolved, and transmitters became more reliable, the rules were relaxed so that sites could be controlled remotely. In FCC lingo, the studio where the operator on duty was stationed was known as the control point. They Commission allowed most stations to have operators with a Third Class license and broadcast endorsement on duty. There were exceptions for directional stations, and those with higher power, which still required the First Class ticket.

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Topics: Vintage Electronics, Vintage Technology

Found in the Attic: Hallicrafters S-20 'Sky Champion' receiver

Posted by Tom Vernon on Jul 19, 2016 10:29:00 PM

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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Topics: Vintage Electronics, Vintage Audio Technology