Products > Test Equipment
HP 1741A oscilloscope - restoration project
tekfan:
--- Quote from: slburris on July 03, 2011, 02:40:31 pm ---Very nice! Of course while I'm staring at the photos, I can't help but notice
the Datron 1072 multimeter in the background. What's that, a 7 1/2 digit
meter?
I'm about to try for a scope repair myself, on a Tektronix 2246. It works,
but the trace is noisy, even when the input is grounded, so I'm suspecting
high ripple in the power supplies. Probably at least a nice recapping job
ahead of me.
Scott
--- End quote ---
If it has a focus problem you might want to check this link out:
http://www.cromwell-intl.com/radio/tek2445a.html
It looks like this is a common problem in the bigger analog Tek scopes. The resistor opens up as it is right on the limit of its power rating. And yes the capacitors should definitely be replaced with low ESR types.
Here's what can happen to the capacitors in the SMPS (German but you get the picture):
http://www.spurtikus.de/basteln/tek2432_reparatur/index.html
The Datron 1072 is actually a 6 1/2 digit meter but 7 1/2 with averaging and filter on.
Here's a review/teardown I did a while ago: https://www.eevblog.com/forum/index.php?topic=3013.msg41015#msg41015
Alex:
Hey tekfan, is that mica capacitor next to the rectifier for some sort of 'line trigger'?
ivan747:
I wish I had the experience to restore things :'(
This looks awesome
tekfan:
--- Quote from: Alex on July 03, 2011, 06:49:22 pm ---Hey tekfan, is that mica capacitor next to the rectifier for some sort of 'line trigger'?
--- End quote ---
Yes! It is exactly that capacitor. It's tapped off the 120VAC secondary of the transformer.
--- Quote from: ivan747 on July 03, 2011, 07:29:29 pm ---I wish I had the experience to restore things :'(
This looks awesome
--- End quote ---
Don't be afraid to buy old non working stuff. This is how I got started in electronics. Well that and taking things apart to see how they work never to put them back again! Looking at a schematic and trying to identify the faulty part can be a very rewarding learning experience itself.
Alex:
--- Quote from: tekfan on July 03, 2011, 09:06:45 pm ---taking things apart to see how they work never to put them back again!
--- End quote ---
I used to put them back together without the PCBs and everyone was wondering why they were so lightweight.
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