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Re: [Amps] Series C in amp output

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Subject: Re: [Amps] Series C in amp output
From: "Paul Christensen" <>
Date: Wed, 14 Feb 2018 09:10:11 -0500
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>" Have not seen this configuration on older Alpha amps or others. Can 
> anyone comment on the purpose?"

My first guess was to lower ESR at that point of the circuit although it
seems to make more sense at say...the loading cap when 160m is selected.
With a string of 500V caps in *parallel*, I'm not clear how that's helping
as a safety measure.  Anyone care to enlighten me?

In the Alpha 87A/89, I believe a 2.5mH choke is used at a point post-SWR
bridge, near the RF output connector as a marginal protection device (for
the reason Vic cited), but more importantly as a static drain for the T/R
PIN diodes.  I know that late 87A amps also use a separate pi-wound RFC
inside the T/R cage as additional means to mitigate static damage.

Paul, W9AC 

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