Hickok 890A Transistor Tester
Richard Knoppow
Hickok 890A transistor tester recently. I can find nothing
whatever about it on the web. Does anyone have a handbook or
know much about them? In particular I want to know what sort
of battery was used. It has clips for five batteries, three
are obviously for C cells but the other is evidently for a
high voltage battery of some sort. Its nearly the size of a
size-D cell but its not. I can get some action from the
calibration adjustment from two 9V batteries in series. I
think the original must have been either a 12.5 or perhaps
22.5 volt cell. If anyone can help it would be greatly
appreciated. I have posted to the test equipment list but my
posts don't seem to show up there.
--
Richard Knoppow
Los Angeles
WB6KBL
dick...@ix.netcom.com
co_f...@yahoo.com
At one time, there were 9 volt batteries of about the "D" cell size
and shape.
Paul
Richard Knoppow
"pdr...@coinet.com" <co_f...@yahoo.com> wrote in message
news:313fc7a1-ba2e-4aca...@u4g2000prn.googlegroups.com...
Paul
Thanks for the reply. It might be but I tried it with a
single 9V battery and it did not seem to be enough. Two
batteries in series allowed the cal adjustment to work but I
don't want to just put 18V on it without knowing what the
actual required voltage is. I found a manual at a pay-for
site but its nearly as much as I payed for the tester.
--
Richard Knoppow
Los Angeles
WB6KBL
Fred McKenzie
"Richard Knoppow" <dick...@ix.netcom.com> wrote:
> Thanks for the reply. It might be but I tried it with a
> single 9V battery and it did not seem to be enough. Two
> batteries in series allowed the cal adjustment to work but I
> don't want to just put 18V on it without knowing what the
> actual required voltage is. I found a manual at a pay-for
> site but its nearly as much as I payed for the tester.
Richard-
There is a 22.5 volt battery about the size of an AA cell, except it is
square instead of round. I used one to convert the flash in an old film
camera from two AA Cells to one 22.5 volt battery plus a similar-size
electrolytic capacitor, as a "BC" flash system. With AA cells, the
flash was not reliable. With the BC system, it never failed to fire.
I'll look through my collection of manual links for the 890. The first
one I checked had an 870, with about 30 pages scanned as individual GIF
images:
<http://www.ko4bb.com/cgi-bin/manuals.pl?dir=11)_Stuff_Not_Sorted/2_Misc_
Test_Equip/Hickok/870>
Fred
K4DII
Fred McKenzie
> I found a manual at a pay-for
> site but its nearly as much as I payed for the tester.
Richard-
I may have found one at EBAMAN.com. Downloading requires registration,
which I assume to be free. It looks like 25 Megabytes if I read the
discription correctly.
<http://www.ebaman.com/index.php/remository/ELECTRONICS/Test-Equipment/Hi
ckok/Hickok-890/>
Fred
K4DII
Scott Dorsey
It's most probably a mercury battery, either the 8.4 or 12.something
variety. As such, it's probably used as a voltage reference and replacing
it with an unregulated alkaline battery will be bad.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Richard Knoppow
"Scott Dorsey" <klu...@panix.com> wrote in message
news:i8r3ni$lp1$1...@panix2.panix.com...
That's possible but there is a "beta calibration"
adjustment on the front panel which is evidently for
compensating the voltage.
Richard Knoppow
"Fred McKenzie" <fm...@aol.com> wrote in message
news:fmmck-2B7EF0....@5ad64b5e.bb.sky.com...
I am familiar with the battery you mean. The clip in
the tester is for something close to the size of a D cell
although just a little shorter. I checked with a variable
power supply and it seems to require around 18 volts to work
so I can use a couple of 9 volt batteries in series but I
would like to know what is supposed to be there. Anything
you can come up with will be welcome. The 870 is a much more
elaborate set, not much similar to what I have.
Richard Knoppow
Thanks, I will have to download it later when I have
access to a high speed line. I am on a dial up here. This
may well be what I am looking for.
Richard Knoppow
Thank you very much Fred, this turns out to be it.
While I have an A version it appears to be essentially
identical. The mysterious battery is a 22.5 volt one so I
think a couple of 9 volt batteries in series will work OK.
Its also, of course, useful to know how its supposed to be
used. While individual transistors are considered obsolete
now I still work on quite a bit of gear that has them and
sometimes something more than a DMM is desirable for trouble
shooting them.