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March 2021 S M T W T F S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Meta
Tag Archives: transistor
Bose® Active Equalizer Test Platform
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 Bose, conversion, Equalizer, sockets, test platform, transistor
3 Comments
Bose® 901 Series II Active Equalizer #64364 Overhaul
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
Posted in Audio, Bose, Electronics, Vintage
Tagged Active Equalizer, Bose, capacitor, hifi, repair, series II, transistor, vintage
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Assembling Transistor Radios in 1955
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 1955, 1959, commercial applications, documentary, history, Little Giant, radio, transistor, transistors, US information service, vintage ad
2 Comments
Harmony H500 Solid State Guitar Amplifier Repair
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
Posted in Audio, Electronics, Projects, Vintage
Tagged 2n3391, capacitor, guitar amplifier, h500, harmony, repair, replacement, solid state, transistor
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New Toy: HP 143 Wide-Screen Oscilloscope Mainframe Restoration – [Part 1]
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 1402a, 1423a, 143a, 143a mainframe, compactron, dual-trace amplifier, HP, hp 143a, mainframe, nuvistor, oscilloscope, oscilloscope mainframe, plug-in mainframe, plug-in oscilloscope, scope mainframe, timebase, toy, toys, transistor, tube, vintage, vintage oscilloscope
8 Comments
1958 Sony TR-610 Transistor Radio Repair
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
Tektronix 575 Mod 122C Curve Tracer Restoration Project – Part 1
A while back I picked up a Tektronix 575 Mod 122C transistor curve tracer from Craigslist and just started digging into it. With some encouragement from reader petepdx, I’ve started actually looking into fixing it up. (Click the photos for a much larger … Continue reading →