[AMPS] TL-922 Filament Transformer Protection

[Rich Measures]

>
>Tom says:
>
>>One cure is to park the resistor outside the suppressor coil, and 
>>series tune it with a small mica cap. That not only increases 
>>current through the resistor at VHF, it decreases resistor current at 
>>HF. 
>
>Another method which is very effective at reducing the current in the
>resistor is to use a one or two turn link in the plate circuit, coupled to a
>parallel resonant tuned circuit tuned to the parasitic frequency, with a
>resistor across that. As in the older editions of the ARRL handbook. It also
>allows tuning out the reactance of the resistor.
>
>I suspect that winding the choke over the resistor was a practice started
>when resistors were generally either carbon composition or the earlier
>carbon rod types, which were essentially non inductive; it saved space.
>
>>Since inexpensive non-inductive carbon resistors are getting nearly 
>>impossible to find
>
>Even EXpensive ones seem impossible to find!
>
€  There is no such thing as a non-inductive resistor.  



Rich...

R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures  


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