These are New Old Stock (N.O.S.) 1D507A (1Д507А) Military Spec Soviet Germanium Diodes. We measured 10 pieces of these on a Peak Atlas DCA55, and the forward voltage on all 10 pieces was .39 at room temperature. These make a fine replacement for the 1N34A diode, and these are the most consistent forward voltage of any Germanium diodes we stock. The opposite side of the dipped glass case are marked with the standard diode schematic symbol, which indicates the anode and cathode.
These are similar specs to 1N993 diodes.
GD507A (1D507A): Uobp Max - Max DC reverse voltage: 20V; Inp Max - Max forward current: 16mA; Unp - constant forward voltage: less than 0.5V at 5mA Inp; Iobp - reverse current: less than 50mA at 20V Uobp; Tvoc ARR - reverse Time 0.1 V - Reverse speed: 0.1 ms; Sde - Total capacity: 0.8 pF
For this item, we will allow returns of your entire quantity of diodes, or none. They must be returned in the same new condition without clipped leads, solder, etc. Because this product varies in exact specification from piece to piece, this policy is to avoid "cherry picking" of parts and returning others. Unless the return is due to our mistake, the customer will pay for return shipping, and will be refunded the original paid price minus the original shipping costs.