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Don Brown[_2_] Don Brown[_2_] is offline
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Default Hickok 440 Curve Tracer Repair Help

On Wednesday, June 26, 2019 at 9:10:30 PM UTC-7, Don Brown wrote:
On Wednesday, June 26, 2019 at 8:06:47 PM UTC-7, John Robertson wrote:
On 2019/06/26 3:42 p.m., Don Brown wrote:
On Wednesday, June 26, 2019 at 1:53:53 PM UTC-7, Don Brown wrote:
On Wednesday, June 26, 2019 at 1:51:20 PM UTC-7, Fox's Mercantile wrote:
On 6/26/19 2:59 PM, Jeff Urban wrote:
Bama probably has it but I can't confirm it right now

They don't.
http://bama.edebris.com/manuals/hickok/

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I looked everywhere for it and ended up buying the hard copy. So I need to scan it and link it.

Here is a photo gallery that I created with the schematic and circuit description: http://www.edfredcorp.com/Hickok/httphotos/index.html

And here is a link for a high resolution schematic: http://www.edfredcorp.com/Hickok/htt...0Schematic.jpg


Hi Dan,

The Heathkit IT-1121 curve tracer is somewhat similar to your schematic..
Have you read that manual?

Pretty sure you can download it from www.tech-systems-labs.com - use
web.archive.org and look in 2007 archives...

John :-#)#

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I will review the Heathkit manual. I am new to curve tracers and have several manuals to study and plenty to learn.

My problem is intermittent. Cannot find what causes it yet. It does not change with length of time on (heat), case open or closed, switch movements or settings, tapping components. Maybe she is like me, getting old and not consistently useful.

I took some photos of when it is at it's best:

Here is a sample curve trace - http://www.edfredcorp.com/Hickok/htt... 0Working.jpg

Here is the calibration screen, fairly normal I think with two steps per division as expected - http://www.edfredcorp.com/Hickok/htt...0 Working.jpg


OK, it has been stable for hours. I repeatedly cleaned and worked all switches and adjusted component clearances to avoid possible touching to case. Also gently flexed the pc board looking for sources of intermittent signs.

Maybe the non electrolytic capacitors needed time to reform, though I did not think it mattered to those.

At this point I did not address the 13v-14v power supply deficit, since it seems to be working. If anybody thinks I should address that for better precision, I will.

Also now have the Heathkit manual for review.

Thanks for all the tips from everybody.