Got this very old scope at a hamfest for free,, figured it was good for parts, but I tried it out before stripping it, and find it kinda works,,, Uses five tubes, 2x 5Y3, B+ and CRT rectifiers,,, 2x 6SJ7s horizontal and vertical amps,,, and an 884... I can't find any info on it online, so I recapped the PS, checked the resistors, cleaned the pots and tube sockets, replaced burned out intensity pot, and got it running...
Dot wouldn't center on the gradicule,,, stayed a little low and to the right of center.... I found that an added resistor allowed a lot more range in the up-down pot, but still need to sort out the left-right range... As long as the problem isn't in the CRT, there's a good chance it will work...
I added the green screen from a scrapped Heathkit...
Any lead to a schematic would be appreciated,,, Thanks...
Dot wouldn't center on the gradicule,,, stayed a little low and to the right of center.... I found that an added resistor allowed a lot more range in the up-down pot, but still need to sort out the left-right range... As long as the problem isn't in the CRT, there's a good chance it will work...
I added the green screen from a scrapped Heathkit...
Any lead to a schematic would be appreciated,,, Thanks...
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I'll bet it would,,, I had it out a couple times but there are no reasonable numbers on it,,,
Its a 5" RCA CRT... It has a 1 and a 44 on the base of it... that's all I could find...
Here's a link to the schem for an Eico 460,, uses a 5UP1 CRT, at about 1200V,,, the horizontal impedance is about 5M... mine is similar, but it pegged a 1500VDC Triplett, reading CRT Voltage off the rectifier... Teh 460 doesn't use the same tubes, but its the closest I cold find...
http://bama.edebris.com/manuals/eico/460/
Its a 5" RCA CRT... It has a 1 and a 44 on the base of it... that's all I could find...
Here's a link to the schem for an Eico 460,, uses a 5UP1 CRT, at about 1200V,,, the horizontal impedance is about 5M... mine is similar, but it pegged a 1500VDC Triplett, reading CRT Voltage off the rectifier... Teh 460 doesn't use the same tubes, but its the closest I cold find...
http://bama.edebris.com/manuals/eico/460/
It might be a 5BP1A. I THINK that's what I saw in another old Eico scope. See here: http://tubedata.milbert.com/sheets/168/5/5BP1A.pdf
Finally got to compare pins on this scope to the 5BP1A data sheet and they don't seem to be the same... Here's the readings I get from the scope CRT... Pin 1= heater,,,,, 2=N/C ,,,,, 3=3.9V,,,,,, 4= -6,4V,,,, 5= -6V,,,, 6,7,8 chassis ground,,,, 9=-2.7V ,,,, 10= > -1500V (pegs meter),,, 11=-920V....
I'll look thru some 5" CRT data sheets and see if anything looks comparable...
Thanks for the input...
I'll look thru some 5" CRT data sheets and see if anything looks comparable...
Thanks for the input...
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