26-10-2014, 09:17 AM
""When the symbol * appears in the selector switch figures, it indicates that the unknown electrode may be connected to a pin internally. To obtain the complete selector switch coding, test with an ohmmeter between the pin marked and all the others (the ohmmeter should be on a sufficiently low range to discriminate between a dead short and the filament resistance). Dependent upon the electrode to which this pin is connected, the correct selector switch code can be set up and the valve tested in the normal manner.
When the pin marked * is open circuit to all the others, set roller to 0.
When the pin marked * is connected to:
Cathode set roller to 1.
Heater - ,, 2.
Heater + ,, 3.
Grid ,, 4.
Screen ,, 5.
Anode 1 ,, 6.
Anode 2 ,, 7.
Diode 1 ,, 8.
Diode 2 ,, 9. ""
Some valves have more than one pin connecting to an electrode eg: some RF valves have two lead outs for the cathode in order to reduce the effect of internal wire/pin inductance at high frequencies.
Lawrence.
When the pin marked * is open circuit to all the others, set roller to 0.
When the pin marked * is connected to:
Cathode set roller to 1.
Heater - ,, 2.
Heater + ,, 3.
Grid ,, 4.
Screen ,, 5.
Anode 1 ,, 6.
Anode 2 ,, 7.
Diode 1 ,, 8.
Diode 2 ,, 9. ""
Some valves have more than one pin connecting to an electrode eg: some RF valves have two lead outs for the cathode in order to reduce the effect of internal wire/pin inductance at high frequencies.
Lawrence.
