[Amps] 9500 amp.

Jim Thomson jim.thom at telus.net
Fri Nov 24 13:48:25 EST 2017

Date: Fri, 24 Nov 2017 09:35:30 -0500
From: "Paul Christensen" <w9ac at arrl.net>
To: <amps at contesting.com>
Subject: Re: [Amps] 9500 amp.

<  An Elecraft KPA1500 is on order and will replace both amps.  The benefit for

- Fast, PIN Diode T/R switching;
- Distribution of weight; PS will rest on the floor and give us much more
desk space with just one solid-state RF deck;
- One amp instead of two handles 160m-6m;
- Native Ethernet connectivity;
- instant on;
- Almost no power consumption in standby; Today, we leave the amps running
with filaments on, then place in operate mode after remote site log-in is

Paul, W9AC

##  leaving the fil on the 8877 tube in  the 9500 means excess wear and tear on the tube itself.
Anytime the fil is lit.... the clock is ticking.    24 x 365 =   8760 hrs.  Thats a lotta  fil hours
per year on the tube.   Dunno how long the fil is good for in the chinese  8877s ?   Thats also
8760 hrs on the blower and everything else in the 9500 amp.   My guess is perhaps  3-4
years max, before the emission drops off.   Is the tube protected if the blower goes dead ? 

##  For your remote operation, the new KPA-1500 is probably the ticket, covers  160-6m,
instant on etc.   As long as its reliable, it should work out good, and greatly simplify  things.  

## Dunno why amp makers just dont use a GH1-RJ1A on both the input..and output of an amp,
IF they are going to use vac relays.    Then the amp will easily handle 1.5 kw when on bypass mode....
in the case where you string 2 x amps in series, nose to tail.  I string 4 x L4Bs  nose to tail, all in series,
then tune em up on different bands, or say 80m cw and 75m ssb, etc.  Simplifies not having to switch
anything at all.   A simple  rotary switch ensures that only one amp can be keyed at any one time. Key
line from xcvr goes to com on rotary switch. Outputs of rotary switch feed the key line input to each amp.
Simple mech interlock. 

##  Even 2 x SS  amps could be wired nose to tail, with a simple relay switched key line.  2 x amps
would ensure redundancy  if the amp function was crucial, or perhaps if remote operation was used,
and remote site was not easily accessible in inclement WX. 

Jim  VE7RF

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