[AMPS] Filaments vs. Heater??

[Phil Clements]

> I just want to ask this question while everyone seems to be following this
> thread on filaments.  I have an amp with 2 3-500Z's.  Filament voltage
> measured, not keyed, at the socket pins is 5.82 volts.  I did drop it to
> 5.00 volts with resistors in the secondary of the filament transformer.  I
> cannot measure the voltage when the amp is keyed due to RF getting into my
> Voltmeter.  My question: is the voltage on the filament almost the same
> keyed and unkeyed?  I am sure with the increase in current during the keyed
> cycle the voltage will drop, , but I have no idea how much.  Any replies
> would be appreciated.
>
> Regards
> Monty/WB5GLB

Measure your a.c. line voltage at the outlet where you have the amp plugged in.
Your drop should be less than 1 volt between no load and full output on the amp
if you have used the proper sized wiring into the shack. If this test passes, you
are
probably okay on the filaments since you have 5 volts no-load to begin with. If
your
drop is more at the outlet, you can do the math to see what happens to the
secondary
of the filament transformer with X number of volts drop on the primary.

GL!
Phil, K5PC




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