Hickock 600A Meter Repair

[Omer S]

Anybody out there that repairs these meters, or knows someone that does?

Omer

[Ken]

Post by Omer S
Anybody out there that repairs these meters, or knows someone that does?
Omer

I've repaired a couple, what are the symptoms? wklw at cox dot net Ken

[Omer S]

Post by Ken

Post by Omer S
Anybody out there that repairs these meters, or knows someone that does?
Omer

I've repaired a couple, what are the symptoms? wklw at cox dot net Ken

The top end of the meter coil with the pointer attached, separated from the
coil and the little top pivot is missing .


Omer

[Jeffrey D Angus]

Post by Omer S
Anybody out there that repairs these meters, or knows someone that does?
Omer

Aside from the problematic nature of Hickok meters, even the ones
in good shape, this one was a rat. So... Rather then spring $175
for a replacement on a equally ratty looking Hickok 600-A tester
"I figured, what's the worst that can happen?".

Root around upstairs in the bone yard and found a used Simpson
Taut Band 100 uA meter movement. 500 Ohm resistance. Ok, the
original meter is 500 uA and 233 ohms.

125 Ohm resistor in parallel with the meter movement. That makes
the meter movement a 500 uA meter, and a DC resistance of 100
Ohms. Add a 130 ohm resistor and now you have 230 ohms total DC
resistance. A new 47 uF 25 volt electrolytic capacitor and you're
done.

pictures over on alt.binaries.pictures.radio

Jeff

[Omer S]

Kudos to a job well done!

Folks, a warning about Jeff.

You leave anything with Jeff for a day, and you get a repair job done beyond
milspec(This project originally started out as a hunt for a replacement
meter)!

This Hickok 600A tube tester, has a brilliant design. The only problem is,
Hickok is known for lousy meters.

With a Simpson meter in the 600A, I'm in seventh heaven!

You got a tube tester on the fritz, send it to Jeff.

Any ways, here is the link of the exact same meter for a king's ransom.,
http://cgi.ebay.com/Hickok-533A-600A-Gm-meter-Transconductance-Black_W0QQitemZ130247297756QQihZ003QQcategoryZ4678QQcmdZViewItemQQ_trksidZp1742.m153.l1262#ebayphotohosting

Omer

P. S. Should I go solid state on the rectifier tubes?

Post by Jeffrey D Angus

Post by Omer S
Anybody out there that repairs these meters, or knows someone that does?
Omer

Aside from the problematic nature of Hickok meters, even the ones
in good shape, this one was a rat. So... Rather then spring $175
for a replacement on a equally ratty looking Hickok 600-A tester
"I figured, what's the worst that can happen?".
Root around upstairs in the bone yard and found a used Simpson
Taut Band 100 uA meter movement. 500 Ohm resistance. Ok, the
original meter is 500 uA and 233 ohms.
125 Ohm resistor in parallel with the meter movement. That makes
the meter movement a 500 uA meter, and a DC resistance of 100
Ohms. Add a 130 ohm resistor and now you have 230 ohms total DC
resistance. A new 47 uF 25 volt electrolytic capacitor and you're
done.
pictures over on alt.binaries.pictures.radio
Jeff

[Peter Wieck]

Post by Omer S
Kudos to a job well done!
Folks, a warning about Jeff.
You leave anything with Jeff for a day, and you get a repair job done beyond
milspec(This project originally started out as a hunt for a replacement
meter)!
This Hickok 600A tube tester,  has a brilliant design.  The only problem is,
Hickok is known for lousy meters.
With a Simpson meter in the 600A, I'm in seventh heaven!
You got a tube tester on the fritz, send it to Jeff.
Any ways, here is the link of the exact same meter for a king's ransom.,http://cgi.ebay.com/Hickok-533A-600A-Gm-meter-Transconductance-Black_...
Omer
P. S.  Should I go solid state on the rectifier tubes?

Post by Jeffrey D Angus

Post by Omer S
Anybody out there that repairs these meters, or knows someone that does?
Omer

Aside from the problematic nature of Hickok meters, even the ones
in good shape, this one was a rat. So... Rather then spring $175
for a replacement on a equally ratty looking Hickok 600-A tester
"I figured, what's the worst that can happen?".
Root around upstairs in the bone yard and found a used Simpson
Taut Band 100 uA meter movement. 500 Ohm resistance. Ok, the
original meter is 500 uA and 233 ohms.
125 Ohm resistor in parallel with the meter movement. That makes
the meter movement a 500 uA meter, and a DC resistance of 100
Ohms. Add a 130 ohm resistor and now you have 230 ohms total DC
resistance. A new 47 uF 25 volt electrolytic capacitor and you're
done.
pictures over on alt.binaries.pictures.radio
Jeff- Hide quoted text -

- Show quoted text -

Just a note for all you Hickok guys - all those uncounted thousands of
Simpson VOMs out there make excellent donors for most of those vintage
tube-testers. It is a bit of a PITA to change the scales and do the
electronic finagling that Jeff did, and perhaps drill an extra hole or
so in the tester top (or fabricating a skirt) - but as against the
cost of a new replacement meter it is nothing much at all.

In point-of-fact, at the Spring Kutztown earlier this year, we did
exactly that to a 539A with a smashed meter - and it came out fine.
Turned a $100 donor tester into a useful piece of equipment. I think
the Donor Simpson came in at $26, and there were dozens and dozens on-
offer ranging in price from $5 to $95 - all cheaper than a new meter
by itself.

And, yes, DO replace any 83 tubes you have with the SS equivalent.
Recalibration (if absolute accuracy is required) is a snap - you have
the tester out of the case anyway - and you won't be fooled into
believing that all your expensive power tubes are all-of-a-sudden bad
or weak. I write "if absolute accuracy is required" on the general
principle that tube-testers are useful but not necessarily dependable
tools for the radio hobby. Unless one is attempting to match tubes for
audio purposes, very fine degrees of calibration are not typically
necessary. So, unless your tester has been re-calibrated as the 83
aged (unlikely unless it came from a lab somewhere), the SS 83-
equivalent will be near-enough to a brand new 83, and so the factory
settings should be fine.

Peter Wieck
Melrose Park, PA

[Omer S]

Post by Peter Wieck
And, yes, DO replace any 83 tubes you have with the SS equivalent.
Recalibration (if absolute accuracy is required) is a snap - you have
the tester out of the case anyway - and you won't be fooled into
believing that all your expensive power tubes are all-of-a-sudden bad
or weak. I write "if absolute accuracy is required" on the general
principle that tube-testers are useful but not necessarily dependable
tools for the radio hobby. Unless one is attempting to match tubes for
audio purposes, very fine degrees of calibration are not typically
necessary. So, unless your tester has been re-calibrated as the 83
aged (unlikely unless it came from a lab somewhere), the SS 83-
equivalent will be near-enough to a brand new 83, and so the factory
settings should be fine.

What type of dropping resistor are we talking about for the 83, and what
about an ss 5Y3 too?

Is there a reason why this guy went through the trouble making these,
hexFRED/heatsink/cluster#^&#s (is there with a better term?) for the 83 and
5Y3?!

http://www.alltubetesters.com/83_5y3.htm

Omer

[Jeffrey D Angus]

Post by Omer S
What type of dropping resistor are we talking about for the 83, and what
about an ss 5Y3 too?
Is there a reason why this guy went through the trouble making these,
hexFRED/heatsink/cluster#^&#s (is there with a better term?) for the 83
and 5Y3?!
http://www.alltubetesters.com/83_5y3.htm

A better look at what he's doing is:
Loading Image...

4 leads that go to the original tube connections.
3 leads that go to a TO-220 package mounted on a heat sink.
1 epoxy block to keep it from being (easily) reverse engineered.

At it's simplest, I suspect it's a pair of 1N4007 diodes and the
item on the heatsink is a high voltage HexFET used as a variable
series resistor. I might just be a regulator, or it might also
be a soft start circuit to mimick the tube filaments warming up.

Jeff