[Techlunch] RF Heater

Dennis Gibson dennis.gibson@anu.edu.au
Thu, 06 Dec 2001 13:55:53 +1100

Thanks to those who have passed on some good suggestions on debug.
Just for the record, the HT does not droop any more than expected and
there is  <5% ripple @ 2A.

The connections to the load coil and load coupling are all OK.  Two load
coils have been tried that set the frequency to either end of the range
(350kHz to 380kHz).  The wave form is a sinewave.  In fact everything looks
good except plate current and power out!  The power is regulated by detector
feedback and is working OK.  The RF oscillator feedback coupling is variable
and runs near minimum, increasing the feedback increases the grid current
but not the plate current.

I will check the filament as I have previously documented it and see if it has
changed, although I would expect it to fail O/C if at all!

I have no data on the valve.

Thanks so far.


Dennis Gibson, Electronics Unit
Research School of Physical Sciences & Engineering
Australian National University, Canberra, ACT 0200

Ph: (02) 6125 2607  [Intl: +61 2 6125 2607]
Fx: (02) 6125 4433  [Intl: +61 2 6125 4433]

Email: dennis.gibson@anu.edu.au