Featured Product

Web Links

•   My YouTube Ch.
•   My Odysee Ch.
•   My Twitter Ch.

•   EEVblog
•   The Amp Hour
•   Mike's Electric Stuff
•   MJLorton's Vblog
•   Gerry Sweeney
•   Jeri Ellsworth
•   The Signal Path
•   Arduino
•   KiCad PCB Design
•   The BreadBoard
•   SDG Electronics
•   The Defpom
•   Big Clive Dot Com


Google Ad

Donate to IanJohnston.com using PayPal here, or pledge a donation via Patreon here.
I like creating electronics related YouTube videos. I mostly buy faulty gear from Ebay and make a repair video of it,
but it's expensive and so with your help maybe I can continue to do so.
If you have any faulty test gear you don't want or going cheap then please contact me. Your support would be greatly appreciated.

Latest Articles.............

Video Blog 117 - HP 3245A Universal Source Repair, Mods & Upgrades - Part 2

In this 2nd video I replace the faulty VFD, fit a new front panel and carry out some initial stability tests comparing it to my other 3245A.
Date: 01/10/23

Video Blog 116 - Keithley 2306 Dual Channel Battery Charger Simulator Repair - Part 2

Further repairs and refurbishment to the 2306, and initial testing.
Date: 15/09/23

Video Blog 115 - Keithley 2306 Dual Channel Battery Charger Simulator Repair - Part 1

This Keithley 2306 has a very typical fault for the series, but with the added bonus of a delaminated 6-layer circuit board.
Date: 08/09/23

Video Blog 114 - Time Electronics 2003S DC Voltage Calibrator Repair & Refurb

Dating from around 1975, a 10V voltage Calibrator from Time Electronics in the UK. I couldn't resist a repair and refurbishment project.
Date: 02/09/23

The Amp Hour #643 - Calibration & Repair with Ian Johnston

I was lucky enough to appear on The Amp Hour podcast with Dave Jones (EEVBlog).
Date: 22/08/23

Video Blog 113 - HP 3245A Universal Source Repair, Mods & Upgrades

In this part 1, I repair the 3245A Universal Source and then set about making some upgrades.
Date: 16/08/23

Video Blog 112 - HP 5300B Measuring System Repair

Donated to the channel, here's a mid-70's HP 5300B Measuring System consisting of a Timer/Counter, Display/PSU and ASCII Interface for repair.
Date: 12/08/23