I have a old 304TL made by Sylvania.
I try to put this tube in circiut with plate voltage 2500volt.
As a book say for AB1 Grid voltage should be -230 volt.
I was made adjustbale regulated power supplay use two VR150 for DC Grid
Voltage.
I was start to adjust Grid V from -300volt, when DC Grid Volt near to -230,
the tube start to arcing.
I was suspect that this tube was "gassy", and I let filamen turning on until
two days (48 hours).
And I start adjust DC grid volt near to -230V again, then problem was the
same, tube start to arcing again.
What the true problem is this, is this tube gassy, and is there any way to
make them work.
Thanks for comments
Firson - YD0LZH
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