Author Archives: retrovoltage

A Most Convoluted 1934 Philco 66B Antique Radio Repair

Posted on May 31, 2013 by retrovoltage

Recently, I took in a beautiful Philco 66B for repair. Manufactured in 1934, this chassis ended up in several different models – a couple of tombstones, a cathedral, and at least two console radios. They’re all 5-tube radios with the … Continue reading →

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Coming Soon: KN0CK Rev B Integrated HF RTLSDR

Posted on May 1, 2013 by retrovoltage

Marty KN0CK developed a very interesting v1.0 HF converter based on surface mount technology that fits inside the casing of an RTLSDR tuner dongle. He’s recently sent me schematics for the revision, which should offer even better performance! This new iteration … Continue reading →

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1934 Silvertone 1708A Repair and Restoration

Posted on April 23, 2013 by retrovoltage

I recently had the pleasure of working on a 1934 Silvertone 1708A which was brought to me for repair locally. This was great – having a radio repaired can be a big decision, so I’m happy to show off my … Continue reading →

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KN0CK HF Upconverter Fits Inside the USB Tuner’s Enclosure

Posted on February 19, 2013 by retrovoltage

Marty KN0CK sent me some details to publish about his great looking miniature HF upconverter board for the RTLSDR, the HF Alchemy DVB-T Active HF Upconverter. It’s an incredibly miniature SMT board with an SA612 mixer and SMT oscillator, and … Continue reading →

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Thrift Store Jamo MPA-101 Repair

Posted on February 11, 2013 by retrovoltage

I started working on a Jamo MPA-101 amplifier back in August for a friend and after some early work it sat for a while. He’s re-doing his audio system at home so I spent a few hours to finish troubleshooting … Continue reading →

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Klipschorn Meets Altec

Posted on February 8, 2013 by retrovoltage

I love old hi-fi stereo equipment, especially the larger stuff which really had a lot of personality. While doing some research on Klipschorns, I discovered a striking reinterpretation of the classic Klipsch design: An Altec Lansing multicell horn in place … Continue reading →

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Bad Capacitors Strike Again

Posted on February 5, 2013 by retrovoltage

I’m working on another Bose 901 Series 1 equalizer. It looks to be the same manufacturing run as the first one I wrote up last July, uses the same components, and those components look like they’ve had the same failure … Continue reading →

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DIY SDR HF Up-Converter by WA7JHZ: Another good choice for your RTLSDR.

Posted on February 2, 2013 by retrovoltage

Reader David Forsman, WA7JHZ, read the round-up of RTLSDR upconverter choices and sent me a photo and build schematic of one he designed which was featured in the January 2013 issue of QST, the ARRL‘s monthly magazine. This circuit up-converts … Continue reading →

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Depression-Era Radio: 1934 Grunow 460 Tombstone

Posted on January 24, 2013 by retrovoltage

I’ve had this Grunow 460 sitting in my queue pending for a little while and it’s finally on it’s way home looking great! There was a fun extra bit of detective work to identify and solve the issues that came … Continue reading →

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First Look: 1934 Grunow 750 World Cruiser

Posted on November 19, 2012 by retrovoltage

I picked up this Grunow 750 “World Cruiser” radio from eBay a little while ago for an incredible deal and now it’s time for it’s turn on the bench. These radios are fairly uncommon and frequently sell for several hundred … Continue reading →

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