Category Archives: Vintage

EICO 221 VTVM Dial Scale

Posted on April 7, 2011 by retrovoltage

In a fit of clumsiness, I sent my EICO 221 VTVM flying off my bench and it struck the ground pretty hard. Not bad for its first major accident since 1959. Everything survived…except the sensitive meter movement, which snapped a … Continue reading →

Posted in Commentary, Vintage | Tagged , , , , | 1 Comment

Refurbishing Vintage Sansui SP2500 Speakers (Crossover Repair)

Posted on April 5, 2011 by retrovoltage

A look at refurbishing the crossovers in a pair of Sansui SP2500 speakers to improve their muddy sound weak highs from early in Retrovoltage’s history with audio repair. Includes links to buy the required parts from Parts Express. Continue reading →

Posted in Electronics, Projects, Vintage | Tagged , , , , , , , | 39 Comments

Seeking Information: 1941 Stromberg-Carlson 520 Radio

Posted on February 16, 2011 by retrovoltage

If anyone reading this has information about a Stromberg-Carlson 520-PG from 1941, I would appreciate if you contacted me. I’ve been trying to find a photo of one that someone else owns, or even a picture of one in a … Continue reading →

Posted in Commentary, Radios and Tubes, Vintage | Tagged , , , | 11 Comments

Antique Capacitor Color Code Chart

Posted on February 16, 2011 by retrovoltage

I’m working on restoring another radio, and it has antique capacitors with color code markings that are different from the commonly used 3-digit codes found today. It took a bit of searching to find a good chart with these, so … Continue reading →

Posted in Radios and Tubes, Vintage | Tagged , , , , , , | 3 Comments

Found: His Master’s Voice (HMV) 444 Radio

Posted on February 3, 2011 by retrovoltage

I’ve added a new radio to my collection, and I think I have a new favorite. This 1934 His Master’s Voice model 444 is a small 5-tube console with Medium-Wave (MW, also known as AM Broadcast) and Long-Wave bands in … Continue reading →

Posted in Radios and Tubes, Vintage | Tagged , , , , | 1 Comment

Refurbishing a Capacitance Tester

Posted on January 20, 2011 by retrovoltage

Parts Express sent me an advertisement for a $45 capacitance meter today. This actually a pretty good deal, and it’s a useful thing to have around if you’re doing electronics work. I’d probably have bought one myself, if I didn’t … Continue reading →

Posted in Electronics, Radios and Tubes, Vintage | Tagged , , , , | 1 Comment

Cost Engineering in the 1930s

Posted on January 15, 2011 by retrovoltage

It looks like cost engineering was already happening back in the 1930s: In the foreground, the destroyed original power transformer from the 1939 Zenith 7-S-363 radio; the rear, an equivalently rated replacement built in October 2010 by Edcor Transformer. In order … Continue reading →

Posted in Commentary, Radios and Tubes, Vintage | Tagged , , , | 3 Comments

Repairing a Vintage Radio (Coronado 907)

Posted on January 13, 2011 by retrovoltage

This is my first project, a 1940 Coronado model 907. This was originally a “high end low end” receiver: it only receives the AM broadcast band, but has three tone settings and mechanical push-button presets. It also uses 7 tubes … Continue reading →

Posted in Projects, Radios and Tubes, Vintage | Tagged , , , , , , , , | 1 Comment