Category Archives: Electronics

1963 Fisher FM-100-B Stereo FM Tuner Overhaul

Posted on August 9, 2015 by retrovoltage

Something a bit unusual came through the shop recently, an old tube-type Fisher FM-100-B Stereo FM tuner. Anyone who knows classic tube audio knows Fisher, and the FM-100-B sure lives up to the name. It’s a 12-tube FM/MPX Only tuner with … Continue reading →

Posted in Audio, Electronics, Radios and Tubes, Stereo, Vintage | Tagged , , , , , | 3 Comments

Revitalize HP and Tek digital scopes with a NewScope LCD kit

Posted on August 1, 2015 by retrovoltage

I’ve been trying to figure out if I want to bother repairing my old HP 1222A oscilloscope which I’ve been using as a waveform monitor attached to the scope ports of my Sencore PA81 Stereo Power Amplifier Analyzer. It’s been … Continue reading →

Posted in DIY, Electronics, Gadgets, Test Equipment | Tagged , , , , , , | Leave a comment

Sony ST-J75 Recap and Alignment

Posted on July 31, 2015 by retrovoltage

The Sony ST-J75 is a pretty well regarded, great sounding stereo FM tuner from the early ’80s. It’s one of the first forrays into digital tuning, with a frequency read-out, programmable memory, and seek/scan functionality and variable muting driven by … Continue reading →

Posted in Audio, Electronics, Hi-Fi, Stereo | Tagged , , , , , | Leave a comment

The Hewlett-Packard 5451A Fourier Analyzer

Posted on July 27, 2015 by retrovoltage

1972: the year launching the Space Shuttle program, the completion of the monument at Stone Mountain, Watergate, the first female FBI agents to join the force….and the new HP 5451A Fourier Analyzer, bringing unparalleled performance to the worlds of acoustic … Continue reading →

Posted in Electronics, Photos, Test Equipment, Vintage | Tagged , , , , , , , , | 2 Comments

1950s Motorola Modded Standalone Tube Amplifier Measurements

Posted on July 6, 2015 by retrovoltage

I had an unusual project through the shop recently. It’s a Magnavox tube amp from the late 1950s. The owner brought it in reporting he’d purchased the amplifier, pulled from a damaged console stereo and modified to be a standalone … Continue reading →

Posted in Audio, DIY, Electronics, Hi-Fi, Projects, Radios and Tubes, Vintage | Tagged , , | 3 Comments

1974 Sony STR-6200F Receiver Overhaul and Alignment

Posted on June 19, 2015 by retrovoltage

I recently got to work on a pretty big, fairly rare Sony receiver from 1973-74: the STR-6200F. It’s a powerful receiver featuring 60W per channel of power available, with quite a few inputs and outputs, and a strong FM tuner … Continue reading →

Posted in Audio, Electronics, Hi-Fi, Projects | Tagged , , , , , , , , | 4 Comments

Marantz 2270 Stereophonic Receiver Overhaul and Adjustment

Posted on May 26, 2015 by retrovoltage

I recently got to work on another iconic piece of hi-fi history, the Marantz 2270 stereo receiver. I’ve had this model through my shop before, as well as a couple of other 22xx receivers and they’re well built and generally … Continue reading →

Posted in Audio, Electronics, Hi-Fi, Projects, Stereo, Vintage | Tagged , , , , , | 4 Comments

Need 45V batteries for your old radio?

Posted on May 21, 2015 by retrovoltage

Rayovac has been making batteries for over 100 years, and their batteries were commonly found in use with many types of battery-operated tube radios. Most commonly, radios would operate on 45V batteries with a tap half-way (for 0-22.5-45V). Two in … Continue reading →

Posted in Commentary, DIY, Electronics, Vintage | Tagged , , , , , , , , | Leave a comment

Yamaha B-2X Check-Up and Adjustment

Posted on May 13, 2015 by retrovoltage

I recently had this Yamaha B-2X through the shop. It’s a massive beast of a power amplifier from the late ’80s, delivering up  to 170W per channel with 0.002% THD. Being somewhat more recent, this one just needed a quick … Continue reading →

Posted in Audio, Electronics, Hi-Fi, Projects, Stereo | Tagged , , | Leave a comment

Extracting Screenshots from the HP 3585A Spectrum Analyzer

Posted on April 22, 2015 by retrovoltage

I’ve posted a few times about my HP 3585A spectrum analyzers over the past several months, and after chipping away at the problem I’ve finally solved the screenshots issue! It boiled down to a bad GPIB cable for my National … Continue reading →

Posted in Electronics, Resources, Test Equipment | Tagged , , , , , | Leave a comment