[Amps] Re: SB-220 plate choke (correction)

[Roy Koeppe]

In order to prevent dipping the TANK, only the 'bottom' end of the choke
should be wired up. Sorry!

Roy     K6XK


----- Original Message ----- 
From: "Roy Koeppe" <royanjoy at ncn.net>
To: "Amps Reflector" <amps at contesting.com>
Sent: Monday, April 26, 2004 7:40 AM
Subject: [Amps] Re: SB-220 plate choke


>
> On Apr 25, 2004, at 5:52 AM, Roy Koeppe wrote:
>
> > Discussed...
> >
> >
>  On Apr 23, 2004, at 3:20 PM, Jeff Weinberg W8CQ wrote:
>
>  Hi All,
>   I am trying to find a plate choke for the SB-220 for a friend in
>   Australia.  Anyone got a spare lying around?
>
>  ð  No, but they are a piece of cake to make.  See
>  http://www.somis.org/D-amplifiers4.html
>  -  cheers, Jeff.
>
>   Thanks,
>   Jeff Weinberg  W8CQ
>
>  Lots in that URL I don't agree with. First he seems not to
distinguish
>  between series and parallel resonances at all.
>
>   Roy --  How do you tell the difference between a series-resonance
> and a parallel-resonance with a dipmeter?
>
> My recall is that you measure for parallel-resonance dips with the
choke
> open circuited, and preferably installed in the amp. (wired in place).
> For series dips, you place a shorting strap directly across the choke,
> and have it out in open space at the time.
>
> Roy      K6XK/0