----- Original Message -----
From: "Jim Forsyth" <jim@forsyth.net>
> This mini thread is about a case where the resistance of the inductor WAS
> significant and possibly DID affect the resonant frequency appreciably.
>
> Jim, AF6O
>
>> At the risk of sticking my foot in my mouth again, R generally
>> doesn't effect the resonant frequency of an RLC circuit appreciably
>> provided that the Q is reasonably high. On the other hand, a plate
>> choke when you look at it very closely is really a distributed RLC
>> circuit, so one has to be careful about applying simplified 3 component
>> lumped element models. I'd love to see a rigorous analytical treatment
>> of this if anyone knows of a good reference.
>>
>> 73 de Mike, W4EF........................................
>
Yes, I understand that, Jim, but I was having a hard time believing that
you could get away with deQing a choke enough to shift the resonant
frequency significantly without turning it into a fireworks display. I did
some google searching and there seems to be little in the way of
analytical information on plate choke design. Mostly it seems to be
an empirical art (e.g. use X # of turns closewound on a D diameter
form kind of thing). My best guess of the equivalent circuit would be
a bunch parallel RLCs in series, but even that I suspect is oversimplified.
The fact that it has multiple staggered parallel and series resonances,
for instance, can't be explained by a simple 3 component lumped RLC
model.
73 de Mike, W4EF..............................................
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|