Category Archives: Projects

Thrift Store Jamo MPA-101 Repair

Posted on February 11, 2013 by jwk

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

Posted on February 2, 2013 by jwk

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 jwk

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 jwk

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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1950 RCA 9X561 Radio Repair

Posted on October 29, 2012 by jwk

A friend I’ve made through the antique radio community is also a repairman himself, but ran into some scheduling difficulty with a piece of work on his bench and sent the chassis over to me for service: an RCA 9X561, … Continue reading →

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Shortwave Radio Reception with the RTL-SDR Dongle

Posted on August 6, 2012 by jwk

Need your own upconverter? Click here! I bought and did a quick setup on my RTLSDR dongle using SDR# a few weeks ago, where I used it to listen to FM radio stations around my area and a few public … Continue reading →

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New Project: Jamo MPA-101 Amplifier Repair

Posted on August 1, 2012 by jwk

Project’s Conclusion Here My friend brought me this Jamp MPA-101 amplifier he picked up at a garage sale, complaining in only puts out some rumbling and humming. It looks like it’s suffered a failure in the power supply at some … Continue reading →

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First Ever Bose 901 Series 1 Active Equalizer Repair

Posted on July 25, 2012 by jwk

While some other projects have been pending information and parts, I’ve had a chance to work on the Bose 901 Series 1 equalizer that’s been on my bench for a couple of weeks. The equalizer is a necessary component of … Continue reading →

Posted in Electronics, Projects, Speakers, Vintage | Tagged , , , , , , , , , , , , , , , , | 37 Comments

Identifying Your Bose 901 Series 1 Equalizer

Posted on July 11, 2012 by jwk

Bose 901 Series I Active Equalizers came in two varieties, which can be used interchangeably, but have fairly different circuit designs. It’s simple to tell them apart for ordering parts for a repair with a quick inspection of the inside. Both … Continue reading →

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Fixing a 1934 Simplex Model P Dual Band Vintage Radio

Posted on June 27, 2012 by jwk

I picked up this 1934 Simplex Model P Dual Band radio for my personal collection about 7 months ago, but haven’t worked on it much until this weekend. It sat on my articulated chassis stand in the corner waiting for … Continue reading →

Posted in Projects, Radios and Tubes, Vintage | Tagged , , , , , , , , , | 17 Comments