Danelectro Model 272

Nice sounding AMP, when it works, weird design, low quality parts and built like a deathtrap.  Very interesting.....

Click here for more info.....

1959 Gibsonette GA-8

Awesome simple single ended Gibsonette 6V6 amplifier from 1959. Initially arrived at my door broken because one filter cap had shorted and caused a fire which burned through the other filter cap.  


Click here for more info

Collection of APRS and packet software installations on linux

Here are Some videos Ive posted on Youtube that include some HAM radio experimentation work done in the April-May timeframe.  Also included is some FREEDV digital voice work.

Click here for more.......... 

TAPR TNC-1 restoration

Restoration and operation of the TNC-1


The first generation Packet TNC is going back online using the venerable Apple][.     No content yet but some photos in the link here

Commodore 64 (board REV C) and older 1541 replacement capacitors from Newark (Element 14)

At this point, any electrolytics in the Commodore are suspect.  Since replacement is so cheap, and failure so expensive, Ive compiled a list for Newark (Element 14) for capacitor replacement.

Click here for more info

The Adventures in repair and recalibration of the HP 331A

Here is my information on the repair and calibration of the HP 331A THD analyzer from the 1960's which is now in working condition and on the bench


Link to My post in EEVBLOG

Heres the Movie on Youtube

ST70 Resurrection PART 9

ST70 Resurrection PART 9

The first test of basic distortion displayed, we run some real tunes through it.  Notice the top of the waveform distorts before the bottom.   This will be covered in the next video

See Part 9 here.......

ST70 Resurrection PART 8

ST70 Resurrection PART 8

Testing of the input signals to the outputs of the 7199's are done showing two outputs exactly 180 degrees out of phase and an injection of an audio signal to display on the oscilloscope

See Part 8 here.......

ST70 Resurrection PART 7

ST70 Resurrection PART 7

This chapter deals with the summary of the electrolytics, testing and repair of the PC-3 board and other fun stuff

See Part 7 here.......

ST70 Resurrection PART 6

ST70 Resurrection PART 6

Revisiting the mistakes from the last video, everything is retested on the PCB and several tubes are selected until a good match is made

See Part 6 here.......

ST70 Resurrection PART 5

ST70 Resurrection PART 5

Revisiting the mistakes from the last video, everything is retested on the PCB and several tubes are selected until a good match is made

See Part 5 here.......

ST70 Resurrection PART 4

ST70 Resurrection PART 4

Here measuments are made of the bias circuit before and after replacing the two 50uf capacitors with higher rated 100uf caps, showing not only more stability but a cleaner DC signal.   Tests are made to the ABCD DC power for the plate voltages but A and B report high due to the missing 7199's to load them down

See Part 4 here.......

ST70 Resurrection PART 3

ST70 Resurrection PART 3

We replace the quad cap which allows us to introduce the rectifier and set up the bias.    We also get some good readings on the RF Choke and do some comparisons between both quad caps.  Final measurements determine that the power transformer is designed for 117VAC

See Part 3 here.......

ST70 Ressurection PART 2

ST70 Resurrection PART 2

Here we explore the power transformer and measure some voltages as the unit is slowly brought up on the VARIAC

See Part 2 here.......

ST70 Resurrection PART 1

ST70 Resurrection PART 1

Here is the amp I'd received from Mike from his brother Pat.  This is an overview of the amp as it arrived with 40 years of dust and other great stuff.  Also initial value collection of components and tube testing

See Part 1 here.......

Hantek 5072P testing videos

All of the Hantek 5072p testing videos are now in one group


See the listing here......

1962 Montgomery Ward C cell battery test

After getting the VTVM working, I was asked if it could then be used to test this early 60's C cell battery.   See the video below for the results!!



See the video here

Heathkit VTVM Turn up and test

My VTVM that I needed for work with Tube amps and antique radios arrived in pristine condition.  After an inspection of the device and testing of the tubes, a calibration was done and It works perfectly.


See the video here......

ST70 build pics from 2006

Photos from the Dynaco ST70 Build

First Run of SIO2PC on the Atari 800

Here is a video of my SIO2PC interface running between the Atari 800 and a Laptop running Ubuntu 14.10 64bit.

AspeQT is from SVN version 77 and compiled for AMD64 with QT5











This is an early attempt and the throughput has been greatly increased since the video was taken.