13-09-2013, 08:08 PM
Ok, I traced the Cct out but I found that it is running on 50V HT not 25 because ithe rectifier is connected across the 2 15V windings. Thinking back this extended the range of the crystals that would work, however it did still work OK on 25V at 1MHz.
Try it on the lower voltage and if necessary increase it (Voltage doubler). I think the L in the anode circuit is around 1mH. The Xtal coupling cap is not necessary but I prefer not to have volts on the Xtal.
Mike
Try it on the lower voltage and if necessary increase it (Voltage doubler). I think the L in the anode circuit is around 1mH. The Xtal coupling cap is not necessary but I prefer not to have volts on the Xtal.
Mike
