[Amps] 4CX1000A

Val val at vip.bg
Sat Jan 28 09:57:20 PST 2012


Don,

How the bleeder resistor would help, if the reverse current exceeds 37 mA? 
At 325 V screen voltage this makes 12 W - the maximum screen dissipation.
I have seen many brand new tubes with much higher maximum reverse current, 
which they use to achieve at moderate power levels. They are good only to 
work at full power in industrial devices.

73, Val LZ1VB



>A bleeder resistor to ground at the tube screen connection should help.
>
> Don W4DNR
>
>
>
>> I forgot to mention that most of these tubes run reverse screen current
>> with low drive and power levels.  Mine (4CX1500B/FU728F) only goes to
>> positive screen current near the US legal limit output.  At that point I
>> tune for max screen current.
>>
>> 73
>>
>> Roger (K8RI)



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