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Re: [Amps] Alpha 87a No RS-232

To: "'Gerry Hull'" <>, <>
Subject: Re: [Amps] Alpha 87a No RS-232
From: "Dick Green WC1M" <>
Date: Wed, 4 Jul 2018 13:42:50 -0400
List-post: <>
Hi Gerry,

I don't know if this will help, but RS-232 in my 87A stopped working after a 
lightning surge. The amp was otherwise fully functional. Like you, I operate 
the amp remotely (though not as far away -- it just in a closet in the 

In my case, the lightning event destroyed a lot of equipment, so the cause was 
obvious. The surge came in on the SteppIR control cables, destroyed their 
driver boards, and travelled to the computer over their RS-232 connections, 
frying the computer, then propagated to every device connected to the computer 
via RS-232, including the 87A and an Acom 2000a. I believe back then I used a 
multi-port RS-232 card, not the USB-to-RS232 hubs I use now. Not clear whether 
the hubs would have saved the devices. I did have an FT-1000D that was saved by 
an external level converter, so perhaps the hubs would have done the same.

In most of my equipment, the typical failure mode was a fried MAX232 chip. But 
in more than half the cases the surge propagated through the MAX232 on a TTL 
line connected to the CPU, destroying it as well.

I replaced the MAX232 chip in the 87A, plus all the other support chips on the 
control board (just in case). But that didn't fix the problem. It turned out 
that the surge had indeed travelled to the CPU, but didn't destroy it because 
all the I/O ports are fused. Thus, only the TTL serial I/O pin was 
non-functional. The CPUs in the rest of my equipment didn't have this 
high-class feature, including the 2000A, the CPU of which was completely fried.

Unfortunately, I needed the RS-232 function and it isn't easy to replace the 
CPU because each one is individually calibrated to its amp at the factory, 
setting such things as the stepper motor positions and fault detection 
voltages. My 87A is one of the older ones, circa 1995. Alpha downloaded the 
calibration parameters for all the amps made back then, but later the computer 
or hard drive where they were stored was lost or destroyed, and they lost all 
the data for all the amps, including mine. I don't know if parameters for later 
amps were saved. Not long ago someone posted a neat procedure for capturing the 
parameters to a file, which I have used to insure against a future CPU failure. 
Without those parameters, the amp has to go back to the factory. I had it done 
at an "Alpha Day" in Bedford, NH that K1RX had very fortunately (for me) 
arranged for YCCC members, and was able to skip shipping the amp to Colorado. I 
was able to wait while Brad fixed my amp. I can't recall all t
 hat he did, but I believe the procedure involved some special equipment and 
about a half hour to an hour to perform. [N.B. I was also able to drive the 
2000a to Krassy's factory and wait while it was repaired, but that's another 

Given that both 87As can't talk, I'd speculate that you had a lightning surge, 
but the question is why it didn't affect any other equipment connected to the 
computer, of which I imagine there's a lot in a remote station. Have you 
checked everything else? I'd be interested in hearing more about your 
investigation into that.

Hope this helps.

73, Dick WC1M

-----Original Message-----
From: Gerry Hull <> 
Sent: Monday, July 2, 2018 7:49 AM
Subject: [Amps] Alpha 87a No RS-232

Hello All,

We have two Alpha 87as at K2LE.   They have been rock solid amps for
However, we operate remotely, and rely upon RS-232 using the great DF3CB 

We have the same failure mode in both amps.   The TX side of the serial
port has failed.   We can command the amp on,
But that is it.   We have verified multiple times and multiple ways that
the cable and ports are working perfectly (short TX/RX Pins on the amp-side 
connector and ensure echo on a terminal program).

I see very little about this subject in the archives.  Has anyone else 
experienced this?

Does anybody know if the Max232 chip is soldered?   This is what I suspect,
since the amplifier is fully functional otherwise.

Is there some master reset we can try with a combo of front panel buttons?

Your collective wisdom appreciated.

73, Gerry W1VE
For Andy, K2LE and the team

Gerry Hull, W1VE  Hancock, NH USA
Member: ARRL, YCCC, YCCCN, CW Ops ph: 1-617-CW-SPARK (find me)

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