Eico 950A Bridge Comparator Schematic - Printable Version
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Eico 950A Bridge Comparator Schematic - Greggshere - 02-01-2019
I bought an Eico 950A on Fleabay last week. It looks really nice on the outside, but the inside is another story. Someone else has been in it and changed quite a bit around, especially the caps and some resistors.
I got both a 950 and a 950B schematic online, but cannot locate a 950A. It appears to be a hodgepodge of both schematics, but with just enough different than both, to really confuse me. I confuse easily anyway. Example: there's an 8mfd cap that looks like it could be original that matches the 950 schematic. It has been disconnected on on end. Someone added two 40mfd in series in its place in a manner that looks to mimic the 8mfd and 4mfd on the 950B schematic. Then there are two 470k resistors in the same vicinity and neither print shows 470K resistors anywhere. Does anyone have an unmolested or at least properly restored 950A that could post some photos of the underside of the chassis. A 950A schematic would be awesome, but it appears to be unobtainable.
I was originally going to just change the power cord and maybe the main cap but after seeing what a mess it is that is not feasible at this time. Any help would be appreciated.
RE: Eico 950A Bridge Comparator Schematic - morzh - 02-01-2019
Greg
They might've tried to achieve 20uF, and the two 470K resistors could be across each capacitor to compensate the leakage current which would result in uneven voltage distribution across the serialized caps.
RE: Eico 950A Bridge Comparator Schematic - Greggshere - 02-01-2019
Thanks for that information sir, because it didn't make any sense to me. I found a Construction manual for the 950A on Fleabay that I just ordered and I'm hoping to check things changed from the original biild by using that.
RE: Eico 950A Bridge Comparator Schematic - 462ron - 02-02-2019
Not the best copy but maybe it will help!
Ron
RE: Eico 950A Bridge Comparator Schematic - Greggshere - 02-02-2019
Thanks 462ron, I have that one and the 950B, but it is a a conbobulation of them both, but different than each, because someone else has modified it. I have a 950A construction manual on the way and I'll most likely use that to try and put it back to original.
RE: Eico 950A Bridge Comparator Schematic - Greggshere - 02-13-2019
Just an update, the construction manual cleared it all up, and it wasn't quite as bad as it appeared. I did get it completely restored and it works very nicely. I love it when a plan comes together.
