[Prev][Next][Index][Thread]

Re: OLD Tubes/Coils - filament power (fwd)





---------- Forwarded message ----------
Date: Tue, 4 Mar 1997 09:10:32 +1200
From: Malcolm Watts <MALCOLM-at-directorate.wnp.ac.nz>
To: tesla-at-pupman-dot-com
Subject: Re: OLD Tubes/Coils - filament power  (fwd)

Hi David,

> I was wondering if anyone knew if the 803's use a thoriated filament? I
> am using two 803's in parallel, with several turns on top of the primary
> of the microwave transformer to get about 9.5 volts to power the
> filaments, since this arangement isn't curent limited, am I in danger of
> damaging these filaments?
> Thanks,
> 
> David Trimmell

There is no problem for filaments which have a _specified voltage_. 
They settle at their own currents. In this case, the applied voltage 
should be within 5% of that stated. Tubes with a spec'd filament 
current are a different matter.

Malcolm