Fico 400 scope...

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...
 

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knockbill

Member
2013-02-26 1:18 pm
SE PA
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/
 

knockbill

Member
2013-02-26 1:18 pm
SE PA
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...