[AMPS] resistance to......

[km1h@juno.com]

On Mon, 21 Sep 1998 17:13:33 +0100 Peter Chadwick
<Peter_Chadwick@mitel.com> writes:
>
>Carl says:
>
>>The resistors as used here are a pair of 100 Ohm 5W MOX in
>>parallel....they do get a bit warm with a 3-500Z at 50MHz but not
>>alarmingly warm after a full minute key down.
>
>Carl, is there not an advantage to the 'classical' approach that as 
>the
>operating frequency goes down, the shunt reactance goes down, so there 
>is
>less loss in the resistors? I was taught that you use the minimum 
>amount of
>inductance that stops the parasitic, 'cos that gives least loss in the
>suppressor.


That has been my understanding Peter which is why I wound up with only a
2.5" strap for the actual inductor. On HF the suppressors run very cool.
At 6M we have to deal with the parasitic that is either close, percentage
wise, to the desired frequency or in some cases the parasitic and 3rd
harmonic are almost the same frequency.
A few 6M amplifier conversions required a lot of time with the old
Measurements 59 GDO to tame things down.

73   Carl   KM1H
>
>73
>
>Peter G3RZP
>
>
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