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Heathkit Restoration
At DIY Iowa I worked out a barter deal with Bill (4thtry) He could have the HP Distortion Analyzer gathering dust on my shelf and in return Bill would attempt to repair my Heathkit IM-5238 AC voltmeter. It returned late last week and I finally had a chance to fire it up tonight.
My Heathkit IG-18 signal generator
My Heathkit meter.
Rear view of the meter.
I fed a 1Khz 1 volt signal into my Fluke 8060A True RMS Multimeter and the Heathkit meter.
Signal generator
The Heathkit and Fluke measurements. The "1" on the 3 volt scale is behind the meter needle.
I must say I was impressed with the amount of work Bill put into this repair. He documented every step he took in great detail. The problem was that after sitting unused for a number of years the meter would peg when it was turned on. He traced the problem to an amplifier circuit and after verify that every transistor was good he decided to re-solder all the solder joints and that fixed the problem. Because of the age (the manual is copyright 1976) we decided to recap it. It was returned double boxed with all his documentation which included data sheets for every part he replaced, curve traces for every transistor he tested, measurements of every cap he replaced and the value of the replacements. He also recalibrated the meter which was spot on in my little test. I'm grateful to Bill for his efforts and look forward to hearing how his new HP distortion analyzer works.
Ron
Comments
Very cool. That looks like it's new. Great job Bill!
That's fantastic - Kudo's to you both!
Right on, Bill! Great to keep another piece of equipment working and out of the scrap bin.
Excellent
Thanks for the kind words, Ron. Glad to see it working again. I really enjoyed repairing it for you.
And thanks again for the vintage HP distortion analyzer. I plan to do a full restoration on it and put it to good use on my test bench. When fully calibrated, this analyzer can measure harmonic distortion at any frequency down to levels approaching 0.05% or so. It is a very nice unit, built like a tank! Bill
Before Heathkit recap:
After Heathkit recap:
The vintage HP distortion analyzer:
I was just a bit too young to enjoy the golden era of Heathkit. That must have been a fantastic time to be interested in learning/building electronics. At the time when tubes and transistors were both killing it!
Our first computer was a Heathkit built by our neighbor (IT guy for then Ashland Oil). Was a basic dos machine, mom used it to keep track of her refunding/couponing.
A guitar player and friend from Church asked me to fix his delay pedal. I opened it up and decided there is no way I can trouble shoot it. The surface mount technology is great for space savings but with my eyes... no way!
I recently picked up a used Heathkit IO-4210 10MHz dual trace oscilloscope at a local hamfest. I have it connected in X/Y mode to a B&K 501A semi-conductor curve tracer, which I also picked up used at a local hamfest. I used it to test several transistors as I attempted to find the problem with Ron's meter. This old equipment is great and just keeps on plugging along!