[Amps] Alpha 87A problems

[Jerry O. Stern]

When you say "Alpha systems"... do you mean AlphaRFSystems?  

Have you tried Brad's K0HM Electronic Repair  or reaching out to Glenn
Pladsen (AE0Q) gm5bkc at gmail.com?

Brad Focken
6288 Gunshot Pass Dr.
Colorado Springs, Colorado 80917
Phone: 719-629-7045
Phone: 303-579-5173
Website: www.k0hm.net

I have notes on virtually everything published on the web about Alpha 87a
faults and I was surprised to find nothing on Fault 16.    Not many parts in
the plate circuit that could fail to cause high plate current on RX.
Could be something as simple as a shorted cap in the HV supply, Any of C1 -
C9.  Could be bad tube.  I recall the original "Alpha" company suggesting
the following check for startup faults (if you are familiar with HV amps):

Disconnect both anodes and let the amplifier go past the 3 minute warm up.
Let it set for 10-20 minutes.  Then shut it off and attach one anode cap and
let it run for 10-20 minutes.  If nothing happens, disconnect the first
anode and hook up the other tube.  Again see if it will idle for 20 minutes.
- If that works, then hook up both tubes.

If it faults on only one tube, replace the tube (or swap to test).  If both
tubes fail individually or together check HV caps for shorts.

If you are not familiar with HV circuits, etc DON'tr try ANY of these !!!!

Can you give us a list of what they repaired for $1500??

73 Jerry
NY2KW


-----Original Message-----
From: Amps [mailto:amps-bounces at contesting.com] On Behalf Of Herbert
Schoenbohm
Sent: Saturday, September 29, 2018 8:28 AM
To: Amps group <amps at contesting.com>
Subject: [Amps] Alpha 87A problems

My Alpha 87A went to Alpha systems in Colorado for repair of Fault 16 that
was occurring within a few seconds of turning it on.  After paying $1500 for
their repair it was returned and immediately when hooked up it showed the
same problem. After numerous exchanges with Alpha systems ( and they said
they never experienced Fault 16) and with me checking everything like RF
deck, removing HV from the power supply, reseating connectors all had
negative results.    I have come to the point where I want to send it back
to Colorado.  Unfortunately the past week, they have been unresponsive to
any of my email trying to make the arrangements.  This leads me to the
conclusion that they are not interested in doing any more repairs for me.
In two years I have spent over $3000 in the repair of this unit and should
have probably bought a new solid-state amplifier instead.


   1. Any suggestions would be appreciated on the Fault 16 problem.
   2. Is there any other place that does repairs on the Alpha 87A?
   3. Are there any 87A users that have had similar problems?

Herb Schoenbohm, KV4FZ
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