Recent content by capriguy7

Ok the IR unit is getting power, it is just not warming up. Can that go bad. Seems like it's a solid state piece of equipment. It is getting 120 ac v across it

Found it, well at least a starting point. The IR does not heat up so it's not getting power.

Thanks will try

Ok so HC shows no hertz reading at all BUT can adjust it when the zero button is pushed in its rock steady. But when I do the span button nothing will not move. Now the CO gives a reading of about 34 hertz. BUT can not adjust nothing, zero or span. Ohmn checked the leads and all are good.

And this is what? Patent number?

Ok will try thanks

It's only the CO that is not able to be adjusted. And as you can see only the two paper tags are still on the unit. Also this was inspected Nov 6th 1975 and Aug 11th 1979. So this unit is minimum 50 yrs old No casting marks can be found.

Looked for a patent number, no luck. Unless it does not say "patent no#" There are a few numbers on paper stickers but nothing that looks like a patent number.

Did clean Optics no change

If I only had a scope

Well I did manage to find the pn Now I just need to find the parts. I have an operating manual which has a very simplified wiring schematic in it. Pn 7049-0961

No. But have had it trouble shot to IR chip defect

Looking for Sun EPA 75 ir chips

Thanks that was the ticket. But now that all is hooked back up, I now have a noisy CO gauge. Can not get it to zero out at all. I guess I have a bad IR chip. Now have to run one or two of those down

Thank you very much, I will take a better look Monday or so. We are off to watch our race car this weekend at Mid-Ohio