Restoring an Old Oscilloscope - Page 1
Forum section: electronics / projects

author: tayexdrums
author_rank: Contributor
timestamp: April 04, 2011, 04:36:05 am
content: I just got an old 5 MHz analog oscilloscope a few days ago, but unfortunately it doesn't quite work right. All I get is this when I turn it on....I want to restore it to working condition, but I don't really know where to start. I know that it is a kit from the 1970s from DeVry School of Technology. I have all of the manuals, schematics, books, etc. Like I said, I really want to restore this thing to working condition. Here are more pictures of the scope........

author: PeterG
author_rank: Frequent Contributor
timestamp: April 04, 2011, 05:16:34 am
content: I would start by looking at the Horizontal timebase and work from there.Regards

author: insurgent
author_rank: Regular Contributor
timestamp: April 04, 2011, 05:27:02 am
content: In all the pics the vertical input is set to "calibrate". I'd flip that up and set all the variable controls to the halfway mark and see what you get.

author: saturation
author_rank: Super Contributor
timestamp: April 04, 2011, 05:26:08 pm
content: Concur. There doesnt' seem to be any horizontal sweep. After turning off the calibrator, which could be a 1Vpp square wave, you should have a single dot, suggesting the horizontal sweep is dead. Try a 1-10Vdc and just touch it on the horizontal inputs and it should cause it to jerk left or right, this might mean the amp is ok but just the oscillator is dead.I remember a scope similar to that in old trade catalogs when I was a kid; it was a kit for DIY.Quote from: Darkman1969 on April 04, 2011, 05:16:34 am

author: Frangible
author_rank: Regular Contributor
timestamp: April 05, 2011, 03:43:31 am
content: That's actually a Heathkit re-badged as Bell&Howell. Most of the semiconductors in there will be marked with Heath's own part numbers. Fear not, there are plenty of sites that contain cross references between Heath part numbers and standard parts.

author: tayexdrums
author_rank: Contributor
timestamp: April 05, 2011, 02:04:43 pm
content: okay, So I should check the horizontal timebase circuit board components? Then , if I find any components that are bad I can find replacement parts by cross referencing them?

author: tecman
author_rank: Frequent Contributor
timestamp: April 05, 2011, 06:38:35 pm
content: With that news, look through here:http://www.vintage-radio.info/heathkit/to find schematics and other docs on Heathkit products.paul

author: slburris
author_rank: Frequent Contributor
timestamp: April 05, 2011, 09:01:30 pm
content: It's a Heathkit 10-102 scope. I checked a few of the schematic archivesand couldn't find that one. Did you get any documentation with the scope?Scott

author: tecman
author_rank: Frequent Contributor
timestamp: April 05, 2011, 09:40:53 pm
content: Quote from: slburris on April 05, 2011, 09:01:30 pmIf that is the correct model, it is on the link I provided.paul

author: slburris
author_rank: Frequent Contributor
timestamp: April 05, 2011, 09:55:07 pm
content: Bah, now that I study the pics more closely, it doesn't haveexactly the same faceplate.I thought Bell & Howell changed just the labeling but otherwisemade no changes to the design?The 102 has specs that seem to match, and it does have a schematicon the vintage radio site.Scott