Tag Archives: transistor

Bose® Active Equalizer Test Platform

Posted on April 13, 2016 by jwk

This project is going to take a while since I’m slammed in the shop, but I’m in the process of converting a Bose® 901 Series I Active Equalizer to  a test platform. With sockets for the transistors, and clip connections … Continue reading →

Posted in Audio, Bose, DIY, Electronics, Stereo, Test Equipment | Tagged , , , , , | 3 Comments

Bose® 901 Series II Active Equalizer #64364 Overhaul

Posted on February 27, 2016 by jwk

This Series II Bose® Active Equalizer came through the shop. It had suffered age-related failures in its electrolytic capacitors, and the resistors had drifted with age and moisture to produce the wrong curves. Fortunately, it’s nothing some maintenance can’t solve! … Continue reading →

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Assembling Transistor Radios in 1955

Posted on December 18, 2015 by jwk

Here’s a great documentary short from 1955 showing how portable transistor radios were assembled. It’s super retro! (2:35) Want to learn more about transistors? Just a few years later the US Information Agency produced an 8-minute short film about the … Continue reading →

Posted in Collections, Electronics, Vintage | Tagged , , , , , , , , , , | 2 Comments

Harmony H500 Solid State Guitar Amplifier Repair

Posted on October 10, 2014 by jwk

And now for something a little different, this time it’s a vintage guitar amplifier: the Harmony H500. The owner sent it to the shop out of the cabinet to be serviced since it quit putting out any sound. It’s a … Continue reading →

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New Toy: HP 143 Wide-Screen Oscilloscope Mainframe Restoration – [Part 1]

Posted on August 14, 2014 by jwk

At the risk of becoming a test equipment collector, I am picking up a few pieces of vintage test equipment that need some work, but will be very useful pieces of shop gear as well as interesting pieces of history … Continue reading →

Posted in Collections, Electronics, Hardware, Projects, Test Equipment, Toys, Vintage | Tagged , , , , , , , , , , , , , , , , , , , , , | 8 Comments

1958 Sony TR-610 Transistor Radio Repair

Posted on May 2, 2014 by jwk

I just finished a new project over at Rain City Audio – 1958 Sony TR-610 Transistor Radio Repair

This Sony TR-610 came through the shop to have its electrolytic capacitors replaced. It was a quick service and this iconic 1958 transistor radio came back to life just in time, only having missed a few Mariners games! With up-rated replacement capacitors and a new battery, it will last for a very long time.

Check it out at http://www.raincityaudio.us/blog/1958-sony-tr-610-transistor-radio-repair! Continue reading →

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