On Sun, Jun 16, 2013 at 11:20 PM, Christopher Brown <[email protected]>wrote:
> You might want to check/replace the current limiting resistor in the > batt charge circuit, and the zener. > I'll check the current limiting resistor for sure. It's a carbon comp, so it could well have drifted. > > Both of my 731Bs had low zener output. > > Had to replace the zeners in both and that 5ma jfet regulator in one. > The E505 has already been replaced with I presume a J505 as it's in a TO92 case. Do you remember what your good zener voltage was? I know they are spec'd at +/- 5% and the J505 is +/- 20% (don't know about the E505, I can't find a datasheet) so there could be quite a range. There is no indication on the part list that they were selected. I have some zeners on order and I'm going to see what I get with 1mA through them. Thanks for the info. Orin. _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
