My EIMAC data sheets even thought it does not specify a heating
time, "----" where a value would be listed, for the 4CX250B or F (listed
in same data sheet) said that it recommends that heater voltage be applied
30 seconds minimum before applying other voltages. But it does not state
that it is absolutely necessary. For the R it list a heating time of 30 to
60 seconds and still has the recommendation of at least 30 seconds minimum
for application of filament voltage before the others. I suspect heating
time may refer to the time to reach full cathode emission.
73
Bill wa4lav
|