Hello everybody,
after waiting a long time for all that good stuff to arrive, i finished my first two boards yesterday.
Inspired by the boards of branadic and Dr. Franks schematic i made my own board, adding a double RC-filter at the input of the LTC1052
and move the power supply to a separate board (not built yet).
The PCB fits into a TEKO 394 housing and it's enough space left for the power supply and maybe a heater regulator for the whole housing.
As you can see, in spite of everything, i forgot to order the LTC1052
R14 will be measured and ordered after the burn-in period. The yellow jumpers can be used to connect the floating copper planes to top or bottom ground.
The boards are nearly without errors, all parts are fitting well and they are functionally. Just the drill holes for the two types of transistors are both a little bit to small.
Unfortunately one of the LTZ1000 seems to be defective. Zener and heater are good, but the junction of the two emitters / Pin 7 has a problem.
On both 70k-resistors i measure too much voltage compared to the running board. It seems, both transistors can't drive any current. Is that a known error?
Bought them as "used but tested" on ebay a while ago, but used them yesterday the first time.
I plan to build another two boards. Is it advisable to look for non-A LTZ 1000?
Best regards
Frank