Minor upgrades, maintenance, and cleanup of a Hewlett Packard HP 3457A digital multimeter.
Hewlett Packard 3457A Multimeter
Power Designs Inc. Model 605 restoration
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.
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.
Nicolet Integra 40 Oscilloscope
I was able to pickup a non-working Nicolet Integra 40 oscilloscope for a bargain price. It was built in 2000 and is a 4 channel differential input unit capable of 20 MS/s with 12 bit digitizers and color screen.
HP 5005B Signature Multimeter cleanup
I have been looking for a Hewlett Packard signature analyzer for many years, but until I found this one they have either been in good shape and really expensive or in poor shape and really expensive.
Tektronix TDS 380 NVRAM Replacement
I finally decide that I had pushed my luck far enough with my battery backed NVRAM in my Tektronix TDS 380 oscilloscope. The specifications for the Dallas Semiconductor DS1644-120 Timekeeping RAM state that it is good for at least 10 years at 25°C, and mine had just turned 28 years old.
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.
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.
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.
Transistor matching test fixture
I had the need to match a batch of transistor pairs for a project, so I designed a circuit board based on a circuit by Ian Fritz.
Keithley 2015 THD Multimeter maintenance
I have had my used Keithley 2015 THD multimeter for just over six years now, and have finally decided to perform some maintenance on it. I purchased it as a fully tested and working unit back in 2016. After it arrived, I did a visual check of internal components and a good cleaning of the exterior.
Power Designs D‑series display board update
After the acquisition of my Power Designs 5015D power supply, I really wanted to upgrade the display module so that I had an extra digit of resolution. I already had a few ADC/LED meter boards left over from previous projects, but needed a display board to pair with it.
Power Designs Inc. 5015D power supply cleanup and repair
Repair and cleanup of a Power Designs Inc. 5015D power supply that I purchased on Ebay.
This was one of the better looking 5015D power supplies that I have seen on Ebay, that was not overpriced or included an overpriced shipping charge. The listings condition description said ” fully operational and functions as intended”.
Fixing Up a Hewlett Packard 1662C Logic Analyzer
Cleanup and mechanical repairs on a 1996 vintage HP 1662C Logic Analyzer to add to my test equipment collection.
Hewlett Packard 34721B BCD Module
Adding a new HP 34700 series module to the collection. This time it is the 34721B BCD interface plug-between module, which converts character serial data from the 34740A or 34750A Display Module to parallel character information for output to a printer.
Hewlett Packard 3551A Transmission Test Set
Checking out a HP 3551A sold as “For parts or not working, will not power on”, that I actually purchased for parts.
My original intent on purchasing this unit was to salvage the knobs and connectors for repairing some of my other HP gear. I did manage to swap out four of the knobs before my curiosity got the better of me.
