Category Archives: DIY

A Surprise in a Re-Stuffed Capacitor

Posted on October 18, 2016 by jwk

I was recently re-stuffing some capacitors for a radio. It’s not something I do often, but I’ve accumulated a pile of pulled vintage caps over the years so I have some on hand if a customer requests the most detailed … Continue reading →

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

Bad Caps in Everything

Posted on July 20, 2016 by jwk

I just had a bit of a scare with my Audio Precision analyzer. The 2004-era Dell OptiPlex GX270 which drives the AP hardware decided it would refuse to power up – just flashing the “ON” light for a fraction of … Continue reading →

Posted in Computers, DIY, Electronics, Test Equipment | Tagged , , , , | 3 Comments

Bose® Active Equalizer Test Platform

Posted on April 13, 2016 by jwk

This project is going to take a while since I’m slammed in the shop, but I’m in the process of converting a Bose® 901 Series I Active Equalizer to  a test platform. With sockets for the transistors, and clip connections … Continue reading →

Posted in Audio, Bose, DIY, Electronics, Stereo, Test Equipment | Tagged , , , , , | 3 Comments

Neat Little 60FX5 Stereo Single-Ended Tube Amplifier

Posted on March 6, 2016 by jwk

While digging around, I came across a really simple circuit in the RCA Receiving Tube Manual describing a 1WPC stereo amplifier using only two tubes, the 60FX5 power pentodes, and a single silicon diode. The 60FX5s have high enough gain … Continue reading →

Posted in Audio, DIY, Projects, Stereo | Tagged , , , , , | 5 Comments

555 timer teardown (and a Retrovoltage drum trigger project)

Posted on February 23, 2016 by jwk

Ken Shirriff’s blog has a fantastic and detailed teardown of a 555 timer, the ubiquitous decades-old timer circuit that turns up in so many places: If you’ve played around with electronic circuits, you probably know the 555 timer integrated circuit, … Continue reading →

Posted in Collections, Commentary, DIY, Gadgets | Tagged , , , , , , | 1 Comment

Building the SSTRAN Part 15 Low Power AM Transmitter Kit

Posted on February 21, 2016 by jwk

Have a bunch of old tube radios, but nothing good on the air in your area? That’s a common problem, and SSTRAN has the solution! I just built one of these to give as a gift, and thought I’d write up … Continue reading →

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

Building a Better Voltage Regulator

Posted on February 17, 2016 by jwk

Glancing through my feeds, I stumbled across a note on The Paleotechnologist describing a new replacement for the venerable LM7805 linear regulator IC. It turns up in a ton of devices, pretty much anything with a medium-current 5V rail including … Continue reading →

Posted in Collections, DIY, Electronics | Tagged , , , , , , , , , , | Leave a comment

How to Read Capacitor Codes

Posted on January 24, 2016 by jwk

I ended up with a massive stash of mil-spec CDE Mica caps recently, and was searching for a refresher on decoding their military part numbers like “CM05FD221GP3”, since the caps came marked for their values but not their voltage ratings. … Continue reading →

Posted in Commentary, DIY, Electronics | Tagged , | 1 Comment

What do we have here?

Posted on December 1, 2015 by jwk

I was reading about how to build a capacitor checker from the December 1959 issue of Popular Electronics and stumbled across something that looked very familiar. I know that shape. Nearly identical to a Bose® 901 Series I/II cabinet, and even … Continue reading →

Posted in Audio, Bose, Collections, Commentary, DIY, Electronics, Vintage | Tagged , , , , , , , , , , , , , | 2 Comments

Mailbag: What’s the best multitester for vintage radios?

Posted on November 2, 2015 by jwk

I recently got this question in the mailbag, and it seemed like a good one to answer: What’s the best multitester for vintage radio repair? That’s actually a tougher question than it seems. The short answer? Well…it depends a bit, but … Continue reading →

Posted in Commentary, DIY, Electronics, Gadgets, Test Equipment | Tagged , , , , | 2 Comments