What tube numbers are ok to run in the socket with NO HIGH VOLTAGE

[357]

I was just curious if we could get a list from 6JE6 6LF6 to 3-500Z and 3CX3000A7 of what tubes you can run in the socket with no HV connected and not hurt the cathode.

thanks!

 

[sp5it]

First of it all, protection circuit should prevent TX when no HV present

 

[linearone]

Why couldn't you light any tubes filament and just stare at it?

 

[Captain Kilowatt]

You do NOT want to apply drive to a tube without HV present. Most will destroy the cathode or grid depending on how it is configured. An exception might be something like the 3CX3000A7 that has a grid dissipation of 225 watts so it might handle drive OK but why would you want to do such a thing?

 

[357]

Not driving it in TX or TX at all, just running idle.
Someone said that some tubes dont like that and it overloads the cathode. Maybe I'm mistaken.

So the theory is to just "test" the tubes with no HV. make sure theres no white smoke, maybe the the heaters run for 24 hours if its sat a long time.
Just to check the vitals before hitting it with hv.

thanks

 

[357]

So far I was told 572B and 3-500z it is ok to run the tubes with no hv.
So others with perhaps a screen voltage and such it might pull current and hurt the tube. thanks!

and "run" I mean idle, no tx

 

[nomadradio]

with no HV connected and not hurt the cathode.

Running a tube with the cathode/filament only should not cause trouble.

73

 

[357]

Running a tube with the cathode/filament only should not cause trouble.

73

ok thank you

 

[Beetle]

Running a tube with the cathode/filament only should not cause trouble.

73

I've seen several very nice radio installations in someone's den, with ambient light shed by the filament of just such a tube. The particular tube might have some internal problem making it unusable EXCEPT that the filament/heater still lights up.
Not MUCH light, but a reminder of earlier days.

Try https://www.etsy.com/market/vacuum_tube_desk_lamp