[Boatanchors] Heathkit IT-28 Cap tester now FIXED!

[Philip Atchley]

Hi All,

Well, after working on it the best part of a week (and I'm usually a fast
worker), the IT-28 capacitor checker is rewired, tested and calibrated!  This
was a major undertaking as I removed virtually every component, tested it and
re-installed or replaced it (nearly all resistors were replaced with modern 5%
types and the paper capacitors replaced with 600 Volt modern units as well as
removing most of the interconnecting wires and cleaning up the wiring in
general.  The original builder apparently had absolutely no clue about what
wire cutters were for or how to build a kit!

During the process I found a number of wiring errors, including BOTH sides of
the Eye tube filament wired to the same side of the filament line.  Needless
to say, this unit never did work and the tubes have 'low' hours on them.

The leakage and bridge circuits both calibrated just fine and those old 2%
scaling capacitors and 1% scaling resistors apparently didn't change value any
noticeable amount..

How does it work?  Just fine.  Tonight I tested the 12 oil/paper capacitors
that were recently removed from a 60 year old Minerva Tropic Master receiver.
MOST were rated between 400-600 Volts and failed the leakage test anywhere
from 25-100 Volts DC.  ONE 600 Volt capacitor made it to 200 Volts before
failing.

73 de Phil,  KO6BB