[Amps] Ferrite-loaded plate choke

[DF3KV]

----- Original Message -----
From: <wc6w at juno.com>
To: <df3kv at aol.com>; <Amps at contesting.com>
Sent: Monday, January 10, 2005 7:37 PM
Subject: Re: [Amps] Ferrite-loaded plate choke
> >How can the effective impedance at the top of the plate choke be 50
> >Ohms,  when the tube output impedance represents for instance 2
KOhm
> >at the same connection?
> >
> >73
> >Peter
>
>
> Hi Peter,
>   The "plate" choke is connected to the "output" (center conductor
of the coil) of the pi-net which will be transformed to a low
impedance as is the antenna connection.
>
>   It may be easier to visualize if you draw the circuit as described
in the old link.

Hi Marv,

It was clear to me that I have the low impedance at the EHT feedpoint
and the high impedance at the tube like with any other choke,
therefore I wondered if I missed something.
When I talk about the impedance of a choke I always mean the hot end,
not the one
where I feed it or decouple it to ground.
I saw also a high power rotary coil by Harris on Ebay lately using
exactly that solution with an inbedded wire, it was taken from a 20KW
broadcast transmitter.
When I build my high power linears I use two vacuum caps anyway, so my
blocking capacitor is always at the 50 Ohm site of the Pi-L network
with a very simple rf choke

73
Peter