Category Archives: Electronics

Bad Capacitors Strike Again

Posted on February 5, 2013 by jwk

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 →

Posted in Electronics, Hardware | Tagged , , , , , , , | 9 Comments

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 →

Posted in DIY, Electronics, Projects, Radio | Tagged , , , , , , , | 2 Comments

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 →

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

Round-Up of RTLSDR Upconverter Choices

Posted on September 14, 2012 by jwk

1/31/2026: This was originally written in 2012 and hasn’t been updated since 2014, but it’s preserved here in case any of the information is useful and to show the state of the ecosystem when RTLSDR first came on the scene. … Continue reading →

Posted in Collections, DIY, Electronics, Radio, Radios and Tubes | Tagged , , , , , , , , , , , , , , , , , , , , , , , , , , , , | 49 Comments

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 →

Posted in Electronics, Hardware, Projects, Radio | Tagged , , , , , , , , | 3 Comments

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 →

Posted in DIY, Electronics, Projects | Tagged , , , , , , , | 2 Comments

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 →

Posted in Electronics, Projects, Vintage | Tagged , , , , , , , , , , , | 4 Comments

Dell Inspiron 1545 with Broken LCD Screen – Dumpster Laptop Repair

Posted on June 22, 2012 by jwk

My apartment has what I like to affectionately call the “free pile”, where neighbors leave things they were throwing out but might have too much value to throw in the compactor outright. I’ve left a few things there myself, and … Continue reading →

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Build Log and Review: Mable Audio VT-86PP Kit Hi-Fi Amp Project

Posted on March 30, 2012 by jwk

About a year ago, someone left a comment that really looked like spam on one of my pages advertising a web store selling tube audio gear and parts for guitar and audio amplifiers. Against everything I’ve ever learned about behaving … Continue reading →

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