Hickok Cardmatic ?

[Henry Kolesnik]

Hi

Both my Hickok Cardmatics, KS-15874-L2 have been mothballed for about 10
years and both exhibit the same symptoms as well as both Cal. Cells are dead
(I've seen the reverse engineered schematic and wonder if anyone has had
success with repair or an external bypass.) I brought both up on a Variac,
no smoke and both draw a little over a 1/2 amp. Cal. B+ indicates the
meters are OK . For example neither will test a known good 12AX7, the meter
tries to go a little backward on Gm, and the 4 button lamp lights indicating
a dual section tube. Does anything come to mind of where I should start or
am I facing cleaning off the test bench and staring at hours of learning the
circuits for basic troubleshooting each mechanical and electronic section?
I kind of feel that there's a common fault that someone with lots of
experience might point out.

tnx & 73
hank wd5jfr

 

[Mark Oppat]

One of the best experts on tube checkers today , especially on Hickok repair
and calibration , is Chris Haedt in Grand Blanc, MI.

He is currently doing some very scientific tests on the way Hickok testers
"run" the tube under test, and why certain testers do not seem to give
accurate readings on some specific types. This is the first time this kind
of research has ever been done to such an extent. Chris has published some
of his findings, I dont know where all are, but he could send or point you
to some of them I imagine.
If I were you, ask the cost for him to do your tester. He also has restored
testers for sale. It seems to me well worth it to have one of his full
restorations done. All my testers have been restored by Chris, and fully
calibrated, and it was well worth it.

I think Alan Douglas will back me up on Chris' abilities. He is doing some
groundbreaking work in this area.

reach him at: [email protected]
remove NOSPAM to reply.

Mark Oppat
Antique Audio

 

[Henry Kolesnik]

If I can't fix it myself I don't keep it!
When you're retired and lost your ass in the market you have to DIY or do
without.
73
hank wd5jfr

 

[Mark Oppat]

Chris is pretty reasonable. You might want to work out a trade, your fancy
unrestored Hickok for an easier to use, more simple fully restored tester.
Mark

 

[Jimmie Stewart]

Henry

Sound like your reader needs to be clean.
Did you stored the Tester with the reader closed, with out the shipping card
in?
Have you looked at this http://www.spiritone.com/~nabil/hickok/
Try testing a simple tube like a 5Y3.
would you like to trade one.

Jimmie

 

[Chris Haedt]

Hi

Both my Hickok Cardmatics, KS-15874-L2 have been mothballed for about 10
years and both exhibit the same symptoms as well as both Cal. Cells are dead
(I've seen the reverse engineered schematic and wonder if anyone has had
success with repair or an external bypass.) I brought both up on a Variac,
no smoke and both draw a little over a 1/2 amp. Cal. B+ indicates the
meters are OK . For example neither will test a known good 12AX7, the meter
tries to go a little backward on Gm, and the 4 button lamp lights indicating
a dual section tube. Does anything come to mind of where I should start or
am I facing cleaning off the test bench and staring at hours of learning the
circuits for basic troubleshooting each mechanical and electronic section?
I kind of feel that there's a common fault that someone with lots of
experience might point out.

tnx & 73
hank wd5jfr

I do think that you may have a cardreader problem. One thing that
can happen is the whole assembly starts to slow down due to old
hardened grease. This makes for nice smooth operation--but the
machine will not work properly. The reader really needs to slam to
work properly. It has to "fire" the pins into the mating female
contacts. If you have Alan's tube tester book, you can see a picture
of the reader and the pins that need to be cleaned. A tiny amount of
white lithium grease (I used some from GC for wiping contacts) is a
good idea on the tips of the pins. Cleaning the cardreader is not
that easy, and requires loads of patience. Oh--It's easy to take
apart--but getting it all back together can be difficult--especially
the first time you do it. Plan for a day of careful work and then you
won't get upset. Make sure you do NOT adjust the nuts on the studs
supporting the reader plates. Getting all that readjusted properly is
a minor nightmare. If you see that the wiring is disturbed or messed
up going to the bottom of the cardreader, it may not be a practical
thing to repair.

The KS Cardmatic is my favorite tester, and the one I use 95% of the
time. You really need to rebuild the whole thing for it to be
reliable. Unlike other Hickok designs, there are many high voltage
filter caps to replace. It takes me a couple of days+ to redo one of
these machines--but I feel they are well worth the effort.

The calibration cell is used to check the meter in the tester and
calibrate the shorts test function. Original cells used mercury
batteries that have all gone dead now. A new calibration cell can be
constructed using Zener diodes--that is how the later ones were made.

I'd go for some sort of trade arrangement also.

 

[Phil Frakes]

Hi Hank.

I have restored dozens of Cardmatics, and I am here in Oklahoma with
you. If money is an issue, I will certainly entertain the idea of
restoring yours and working out a trade for the payment.

On a related note, if anyone reading this has any junker USM-118B,
Western Electric KS-15874, or RD Instruments 1234 Cardmatic(s) I would
be interested. I am in need of several power transformers.

-Phil Frakes WB5PVL

http://www.tubesontheweb.com