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[Amps] 9500 problem

Subject: [Amps] 9500 problem
From: Thomas Walsh <>
Date: Mon, 26 Nov 2018 14:45:32 -0700
List-post: <>
 I saw your post on the amps reflector and thought I 
would reply, I've been repairing the 9500's at Alpha since 09'. A couple of 
questions, if your antenna has swr of 1.2:1 already why are you using a tuner? 
Never just swap the tube with an unknown without setting idle I. Also if that
tube arcs over, it will take out the 40v bias supply
and possibly some fets on the main control board
as well. Especially if no updates have been done.
 Have you had any of the mods and/or upgrades done?
Has firmware ever been upgraded? What is the SN?
Do not upgrade the main controller without upgrading
all the other pics to current fw, this will require a complete recalibration of 
the amp!
Before that, I would replace the original tube, remove the tuner between amp 
and antenna, and try using autotune to
tune the amp to that antenna at 1.2:1. Start with 20w
input hit auto and ramp up the drive until 1500 out.
Then don't forget to hit "save".
So you saw zero out and gain meter in the red,
that will give a gain fault usually caused by mistuning.
Did you hit "auto" to make the amp retune? By having
that tuner after the amp, will cause problems with
tuning. Each time the amp retunes, that tuner if auto will
again change tuning causing amp autotune to get lost.
If you still have problems, contact us at  contact service.

From: "JTB" <>
Date: November 25, 2018 at 15:13:46 MST
To: <>
Subject: [Amps] Alpha 9500 problem

Fellow Amp Aficionados,

Was looking for some new countries on CW during the weekend contest and
developed an Alpha 9500 amp issue. I was calling a fellow on 15 meter CW
with about  a KW output through an HF auto tuner to a matched Yagi (VSWR 1.2
). I looked at  my Power Master II wattmeter and noticed zero output. Looked
up at the amp and saw the Red LED gain flashing as I keyed the amp. A 1 was
present on the Green digital readout. Looking at the manual and checking all
the recommendations didn't fit my problem. All voltages were in the
acceptable level on the Alpha Remote control software. HV about 3800 checked
with Fluke VOM and HV probe. I can key the amp but nothing out. The FT-5K
SWR indicator flashed high SWR with 15 watts out to the keyed amp. I swapped
the 8877 tube out just to see if the heater had gone open reasoning the high
input SWR.  Same issue with  the new tube ! The heater in the removed tube
checked with a Fluke digital VOM. The issue is present on all bands. When
the amp is on standby the exciter's 10-15 watts is indicated on the
wattmeter with a flat SWR indicated. It looks to me that the amp is not
selecting and closing the tuned input relays. 

Has anyone else run into this problem? Where is the tuned input board
BCX_X430 board located in the amp?

Missing DX OUCH ! ! ! 

Sent from my iPad
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