Restoring vintage electronics along with designing and building new circuits. One eye looking into the past, the other looking into the future.
Minor upgrades, maintenance, and cleanup of a Hewlett Packard HP 3457A digital multimeter. I purchased this HP 3457A multimeter as an untested unit that powers-up. Luckily when it arrived it turned on and had no errors after performing all the self-tests.It was not in the best condition and very dirty with lots of adhesive residue. Continue reading "Hewlett Packard 3457A Multimeter"
With eleven power supplies already, I really didn’t need another one for the bench. Especially one from the early 60’s that was rated at a maximum of 6 Volts and 500 mA of output power. But this one is a somewhat rare Power Designs Inc. model 605 precision power source. It ticked off most of Continue reading "Power Designs Inc. Model 605 restoration"
The Victor 204R is different, but very much the same calculator as the Victor 204 Medalist originally produced by Victor Comptometer Corporation. I picked up this calculator at a better than bargain price, that was almost a giveaway. The Victor 204R is a 12 digit calculator with memory and percent function. This unit was made Continue reading "Victor 204R Calculator Checkup and Cleanup"
After repairing the Nakamichi 610 FM Tuner / Preamp back in late 2023, I have been on the lookout for a FM tuner for the workshop audio system. Since I already had the Hafler DH-110 Preamplifier, I set my sights on the DH-330 FM tuner which has the same styling as the 110 preamp. After Continue reading "Hafler DH330 FM Tuner Repair"
This time I am working on another radiation scaler/counter which is quite a bit different than the last one. This one is a decade newer from 1975 and was built by NMC (Nuclear Measurements Corp.). It has a built-in proportional counter, but has external inputs for Geiger-Mueller, Scintillation, and other sensors. This unit has eight Continue reading "Nuclear Measurements Corp. PC‑4 Proportional…
I finally came across a hard to find HP 5306A Multimeter/Counter paired with the HP 5300B Display module. It is an interesting module as it converts resistance and DC/AC voltage to a frequency that it then displays on the 5300B display, along with a frequency capability of 40 Hz to 10 MHz. This unit had Continue reading "Hewlett Packard 5306A Multimeter/Counter"
After installing a dual-input power transfer panel for power outages at the house, I was in need of a large battery for powering the second UPS input on the panel. The first input on the panel is for my backup generator, but I wanted some power available until the generator was able to be started Continue reading "Building a 7.2 KW LiFePo4 Battery"
Something a bit different than my usual test equipment and calculator projects is this Picker Nuclear Compact Scaler built by Intertech.Quite a few people may be wondering. What is a “Scaler” and what is it used for?A “Scaler” is a counting device that totalizes the events detected over a period of time. Typically used with Continue reading "Picker Nuclear Compact Scaler"