[AMPS] TL-922 Filament Transformer Protection

Peter Chadwick Peter_Chadwick@mitel.com
Tue, 8 Jun 1999 09:41:25 +0100


Dick says:

>Both Tom and Jon have indicated that some RF goes through the resistors at
>10M, contributing to the overheating. 

More fundamental current goes through the resistors as the frequency goes
up, because of the increasing reactance of the shunt inductor. I suspect
that because most parasitic suppressors are 'designed' on an empirical
basis, very little (if any) thought is geiven to the actual dissipation in
the suppressor resistors.

As far as having the resistors inside the inductor is concerned, many people
got away with it for a long time. But it doesn't appear to be the brightest
thing to do, does it, putting a lossy conductor  tightly coupled to the
magnetic field, such as to try to increase the RF current in the resistor?

73

Peter G3RZP



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