Taking delivery of an old Sprauge TO-5 Tel-Ohmike cap analyzer at the end of the week. There are several caps in there that always seem to drift out of range so I'm looking for replacements. These were +or-2% paper dialectric caps.
One is a 2uF 400VDC cap that I have seen replaced with two 1uF 1% caps and the other is a 0.02uF 600VDC cap.
A quick look at both DigiKey and Mouser shows nothing like that in film caps. How do I go about sourcing appropriate parts to bring this unit back into spec?
Also where can I get some quality reference caps to do the final calibration?
Thanks
BillWojo
One is a 2uF 400VDC cap that I have seen replaced with two 1uF 1% caps and the other is a 0.02uF 600VDC cap.
A quick look at both DigiKey and Mouser shows nothing like that in film caps. How do I go about sourcing appropriate parts to bring this unit back into spec?
Also where can I get some quality reference caps to do the final calibration?
Thanks
BillWojo
According to the parts list, their 2% caps were caps chosen for value. In other words they bought a bunch of caps and measured them, then used only the ones within 2%. You can do the same, buy ten 0.02 caps and measure them, pick one close in value. In fact the 2uf cap, they even specify it was a pair of 1uf in parallel.
Manual:
http://www.mcmlv.org/Archive/TestEquipment/Sprague_TO5.pdf
I have the similar unit from Eico, an old 950B. Everyone made one of these bridges in the day. The readings are approximate at best.
Manual:
http://www.mcmlv.org/Archive/TestEquipment/Sprague_TO5.pdf
I have the similar unit from Eico, an old 950B. Everyone made one of these bridges in the day. The readings are approximate at best.
The Sprauge cap analyzer came in yesterday afternoon. I had a chance to look at it this afternoon and was amused by what the factory did for the two 1uF 2% caps. In their place was two 1 uF 10% caps with a parallel 0.1 uF cap. I guess they ran out of close tolerance caps and used what they had on hand. All Sprauge of course.
BillWojo
BillWojo
TubeSound is the go-to place for the set:
https://tubesound.com/parts-accessories/
I got a set for an Eico bridge - same values as the Tel-Ohm-Mikes. For the TO-6, he has all 5 caps, matched, for $43, free shipping.
It saved me some time in hunting/matching and ordering from three vendors...
https://tubesound.com/parts-accessories/
I got a set for an Eico bridge - same values as the Tel-Ohm-Mikes. For the TO-6, he has all 5 caps, matched, for $43, free shipping.
It saved me some time in hunting/matching and ordering from three vendors...
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