Nuclear Measurements Corp. PC‑4 Proportional Counter

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.

NMC Nuclear Measurements Corp PC‑4 Proportional Counter after restoration
Continue read­ing “Nuclear Measurements Corp. PC‑4 Proportional Counter”

Hewlett Packard 5306A Multimeter/Counter

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.

Hewlett Packard 5300B Measuring sys­tem with 5306A Multimeter/Counter
Continue read­ing “Hewlett Packard 5306A Multimeter/Counter”

Building a 7.2 KW LiFePo4 Battery

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 and at night when pow­er usage would be low and the gen­er­a­tor could be shut off.

Bunch of LiFePo4 bat­ter­ies 100 of them at 25 Ah each
Continue read­ing “Building a 7.2 KW LiFePo4 Battery”

Picker Nuclear Compact Scaler

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 a Geiger-Muller tube or scin­til­la­tion detec­tor for mea­sur­ing ion­iz­ing radi­a­tion. It is often referred to as a nuclear scaler.

Picker Nuclear Compact Scaler count­ing at 100 Hz and HV set to 1,000 Volts
Continue read­ing “Picker Nuclear Compact Scaler”

Nakamichi 620 Amplifier Repair

After the restora­tion of the Nakamichi 620 ampli­fi­er last year, it had been work­ing great for 6 plus months. Then one day I turned it on and there was no sound out­put. Luckily the speak­er pro­tec­tion cir­cuit did it’s job and no speak­ers were dam­aged. The right chan­nel had it’s out­put short­ed to B+ (53 volts).

Nakamichi 620 ampli­fi­er with new mod­ules at 120 watts out­put power
Continue read­ing “Nakamichi 620 Amplifier Repair”

Power Designs TP330 Power Supply

I decid­ed to take a gam­ble on pur­chas­ing a Power Designs Inc. TP330 triple out­put pow­er sup­ply. It was a bit rough look­ing with a bunch of stick­ers on the front pan­el, but no scrape marks from past stick­er removal vis­i­ble. The sell­er stat­ed that the bot­tom ana­log meter was non-func­tion­al, but the out­put ter­mi­nals mea­sured volt­age that changed with the volt­age knob.

Power Designs TP330 pow­er sup­ply as received
Continue read­ing “Power Designs TP330 Power Supply”

Beckman 7360R Universal EPUT® and Timer Restoration

Several decades ago I owned two Beckman / Berkeley mod­el 7360–20 Universal EPUT® and Timer’s. Because of their size and weight and an upcom­ing move, I gave them away to a friend. In the past few years I have some­what regret­ted that deci­sion, even though it was prob­a­bly for the best. So when I saw this 7360 up for auc­tion, I decid­ed to make an offer on it. I was able to pur­chase it at a rea­son­able price, but as expect­ed the ship­ping was a bit high due to it’s size and weight.

Beckman 7360R Universal EPUT & Timer
Continue read­ing “Beckman 7360R Universal EPUT® and Timer Restoration”

Nakamichi BlackBox Series Refresh

I was gen­er­ous­ly donat­ed three Nakamichi BlackBox series units, by the same per­son who donat­ed the “System One” rack from a pre­vi­ous post.
The units were in great con­di­tion, and more than like­ly could have been used as-is. They also sur­pris­ing­ly came with their orig­i­nal own­ers man­u­als, which usu­al­ly get mis­placed or lost over the years.

Nakamichi BlackBox mod­ules PS-100 BA-150 EC-100
Continue read­ing “Nakamichi BlackBox Series Refresh”

HP 3314A Function Generator Repair

I found a great deal on a Hewlett Packard 3314A 20 MHz func­tion gen­er­a­tor that was non-func­tion­al, but over­all looked to be in good shape. It arrived in great con­di­tion and was well packed for a nice change. The sell­er clear­ly stat­ed the issues with this unit such as errors when start­ed up cold, which wors­ened over time until it final­ly lost the dis­play and LED’s.

Hewlett Packard (HP) 3314A Function Generator operational
Continue read­ingHP 3314A Function Generator Repair”

Nakamichi 610 Control Preamplifier Lamp Replacement

I did not take any pic­tures of the ini­tial refur­bish­ment of the Nakamichi 610 con­trol pre­am­pli­fi­er as it was main­ly clean­ing and capac­i­tor replace­ment. But as soon as I thought the work on all the com­po­nents of the System One rack had been com­plet­ed, one of the dB meter lamps failed in the 610 preamp.

Nakamichi 610 con­trol pre­am­pli­fi­er after restoration
Continue read­ing “Nakamichi 610 Control Preamplifier Lamp Replacement”