Archive for June 2014

HP 5350B Microwave Counter Teardown

Here is a teardown you do not see very often. I recently bought an HP 5350B 20 GHz microwave counter off eBay. HP 5350B uses harmonic heterodyne down-conversion technique to convert the microwave frequency into the range of its internal low frequency counter. It can measure frequencies from 10 Hz all the way up to 20 GHz via two separate inputs. Continue reading ‘HP 5350B Microwave Counter Teardown’ »

MF 10A Analog Multimeter Teardown

Dave did an analog multimeter teardown in his latest episode. I have a Chinese made MF 10A multimeter bought back in the 90’s and thought I’d do a teardown to take a look at what is inside. Continue reading ‘MF 10A Analog Multimeter Teardown’ »

An Old Tung-Sol Germanium Transistor

I recently bought a few old power transistors from eBay. These are PNP Tung-Sol germanium transistors. According to the date code (6326) these transistors were made back in 1963, long before I was born. The last time I actually used a germanium transistor was more than twenty years ago when I was learning to make transistor radios. Continue reading ‘An Old Tung-Sol Germanium Transistor’ »

Keithley 197 Teardown and Repair

A few days ago, I bought a Keithley 197 sold as “unknown working condition” on the cheap. The seller said that some of the keys on the meter were unresponsive. I figured that I’d try fixing it if I could. After all, these 5 ½ meters still fetch well over $100 on eBay and for a fraction of that price, I was willing to give it a shot. Continue reading ‘Keithley 197 Teardown and Repair’ »