Heathkit IT-28

Workshop Project #23 - Heathkit IT-28

I am always out there, hunting for interesting devices on e-bay... and I couldn't believe my luck when I found this little gem of old school homebrew electronics: a Heathkit IT-28 on sale in the UK; I put in a bid and - just by sheer luck - won the auction with about 3 Euro and change under my maximum bid. Either that or the system is rigged. But hey, here I am: proud owner of an old school capacitor tester.

The instruction manual, complete with description and circuit diagram, is out there as PDF and was really helpful in making sense of the typical tube point-to-point wiring. They sure cared more about function than recognizable wire paths back then.

Join in as I unpack and fix up this little gem! As seen on @MrCarlsonsLab you might say: he has one of those and occasionally uses it too!

0:00 Intro / Overview
1:20 Unboxing / Disassembly Start / Transformer
3:05 Front Panel Disassembly / Goo?
4:50 Electrolytics / Resistor / Voltage Switch Claening
6:48 Mains Switch Claening / Mode Switch Claening
8:09 Binding Posts / Case Straightening
9:04 Case Painting
9:57 Power Cord / Panel Mounting
11:26 Binding Posts / Electrlytics Replacement
12:37 Adding Case and Power Plug / Power Up / Tube Test / Blown Fuse
14:22 Power Up with New Eye Tube
15:00 Leakage Circuit Outline / Calibration
16:22 Testing the Replaced Electrolytics! / Replacing Reference Caps
17:36 Bridge Circuit Features / Carry Handle
18:40 Overview / Summary / Credits / Outtake

Music:
My Train's A Comin'
Unicorn Heads
(YouTube Audio Library)

[matthiasjagdm]

Hurrah my favourite mini cat, big grunt and cool camera cat has given us another video, it is as always Nieeece

[QsTechService]

came out pretty good good job bringing it back to life
They’re definitely cool meters

[LifeBloodMarketing]

Recently did the same test with the original filter cap, one of them anyways. It wasn't to bad for it's age.

[PapasDino]

Now binge watching! Looks like you may have left the line noise suppression caps in place and didn't replace with safety caps? I may have not seen that correctly. Thanks for another great restoration!

[georgegonzalez]

Hey, I have one of those, but in the older early 60's dark Heathkit Blue color.

It's way overdue for a refresh of at least the capacitors. Oh BTW, I wouldn't mount the electrolytics that way unless the tops are very well insulated from touching the chassis. Also the capacitors across the line to chassis are a bit of a risk these days, I'd replace them with AC line rated capacitors. That's mostly compensated by your using a 3-wire line cord, so at worst you'll blow an house fuse, not electrocute yourself.

[howardeisenhauer]

All the Really cool cats have a nut driver set. :\

[KeritechElectronics]

Nice restoration! I love your videos and appreciate them a lot.

When I saw the wire harness, it sparked my interest right away... was it factory made and supplied as a part, or did the person who assembled the unit make it themself? So, a deep dive into the manual and the wire harness was indeed made by Heathkit.

Nice lamp cord, although I'd rather use something with double layer of plastic underneath that sheath.

[waaos]

Your videos would be MUCH better if you ditch the annoying puppet.