[Amps] Alpha 87A problems

Sat Sep 29 13:29:57 EDT 2018

Jerry,
Thanks for your reply on this problem I am having with my 87A. Yes, the
repairs attempted were by  AlphaRFSystems.  I have sent many emails to
service@ AlphaRFSystems.com but now Glenn is not responding at all.  I have
removed the tubes and even the HV output from the power supply proving the
problem is not in the tubes or RF caps etc. I have tested all the filter
caps and even the HV bridge seems fine.  I will reach out to Brad Focken
because I guess he is no longer with AlphaRFSystems.  Somebody has got to
know what fault 16 is all about.  Here is a list of things that
AlphaRFSystems did for $1500: (Nothing related to /fault 16 which was noted
as a problem when the unit was sent to them)

11 hours technician labor  $1120
10K pot   $23.00
The rest was all low voltage caps, zeners, diodes, 2 pin connectors,
ceramic fuses to replace the regular fuses in the unit, Non of this had
anything to do with fault 16 which was noted on the original repair
request.  and they charged me $100 for a double box and shipped the 87A in
a single box.  I had sent the unit to them in an adequate double box which
had been saved from the last trip to them. I don't deny that they spent
many hours looking for problems.  But it is apparant they dd not address
the Fault 16 problem and told me it never occurred at their facility. The
line voltage is 232 VAC. The unit has the AC taps on the highest voltage
selection.

Any suggestions would be appreciated.

Herb Schoenbom, KVfz

On Sat, Sep 29, 2018 at 1:43 PM Jerry O. Stern <jsternmd at att.net> wrote:

> 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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