[Elecraft] KPA500 shutting down

Tue Nov 29 11:13:31 EST 2016

A final update on this, as the problem is solved.

Jack looked at the logs and had a number of things to comment on, all very
helpful.  I knew this was not going to be solved without a trip to the
remote base.  It was not a simple software problem.

I am a big fan of looking at the facts (not guessing) and trying to work
out what may be contributing to the problem.  One of the things that Jack
said was:

*At this point I highly suspect the power source or the KPA supply. The
hypothesis is that when the power drain from the KPA rises, it causes the
supply source to drop, ending in *
*the problems you are seeing. The problem could be in the KPA’s power
connections, either through the switch or the power cord, or beyond this.
This is further supported by the High Voltage (too high) faults.*
*This usually means a wide swing on the AC supply, which could be due to
the power company or further point at the AC supply feed. Unfortunately
this means a long trip to the site to check on things, but if you have an
AC supply problem, this is warranted. Sorry to be the bearer of bad news.
If my analysis is indeed correct, you will want to correct the issue, then
check the supply voltage from the transformer to make sure it stays below
the maximum for the HV (90 volts).*

When I got to my remote base, I found 2 trees had landed on my power feeder
lines.  While the lines were not broken, the Neutral line was and this was
the problem as the system was unbalanced.

I called Ontario Hydro (Hydro One) and they had 2 guys and a bucket truck
onsite within 30 minutes.  The line was fixed within another 30 minutes and
after that, the Amp worked as it should.

It is a good thing it wasn't during the summer as I would have lost a lot
of appliances.  The only things running had switching power supplies in
them, so they survived.

Thanks to Elecraft for the excellent customer support and the smarts to
have good logging data in their amplifier to assist in diagnosing issue.

Many 73, Mike va3mw

On Wed, Nov 23, 2016 at 7:42 AM, Michael Walker <va3mw at portcredit.net>
wrote:

> I wanted to say thanks to Jack for spending time after hours analyzing my
> KPA500 log and providing some detailed analysis.
>
> While I haven't solved the problem yet, I have enough clues that possibly
> support my theory of a bad AC supply line.
>
> I will likely get to my remote base over the weekend, so I should have the
> next clue on why it fails by then.
>
> It is thanks to the support of Elecraft that I buy their product.  In
> fact, when it comes to HF, I only use US manufactures for radios and
> supporting products.  That is because they all provide amazing service!
>
> Mike va3mw
>
>
> On Tue, Nov 22, 2016 at 2:04 PM, Guy Olinger K2AV <k2av.guy at gmail.com>
> wrote:
>
>> Perhaps outdoors you have had a ground go bad, or a connector go bad, to
>> all of a sudden have RF in the shack. Connection work loose, that kind of
>> thing. These could happen without your seeing SWR on the line you are
>> transmitting on.
>>
>> 73, Guy K2AV
>>
>> On Tue, Nov 22, 2016 at 8:53 AM, Michael Walker <va3mw at portcredit.net>
>> wrote:
>>
>>> I run a remote base with a KPA500.  The Amp is a 3 hour drive away.
>>>
>>> I can control just about everything remotely without effort.  The
>>> installation has been rock solid for years (Flex 6300 / KPA500)  and lots
>>> of chokes everwhere.
>>>
>>> Last week the unit worked fine.  Today the KPA500 appears to shut down
>>> based on the Remote GUI.
>>>
>>> I will be on SSB, and then I see the bar at the bottom go to PWR OFF,
>>> reset
>>> and go back to Powering ON/ Amp On.  This is when the amp is only
>>> producing
>>> about 300 watts peak (about 24 watts drive).
>>>
>>> There are no error messages displayed at all and the only thing I suspect
>>> it might be is low AC voltage into the amp.
>>>
>>> RF could be the problem, however in 2 years running contests, this is the
>>> first time I have seen a shutdown like this.  I run many Mix 43 chokes on
>>> all coax and signal lines.
>>>
>>> Are there other messages I can see by monitoring the Serial port at all?
>>> Any thing else I can do remotely?
>>>
>>> I can recreate this on 160/80/40m.  Those antennas are at least 150 ft
>>> from
>>> the station.
>>>
>>> Also, at times, the GUI will seem to freeze.  The buttons work, but the
>>> bar
>>> graphs are stuck frozen in time at a peak reading.  Yet, I can power off
>>> the amp when this happens.
>>>
>>> Currently, the amp is about 34F ambient temp.  In the past, I have used
>>> it
>>> well below that (-25F) without issue (last winter).
>>>
>>> My question is to the Elecraft guru's.  Any thoughts?  I am trying to
>>> retrieve more data from the KPA500 remotely.
>>>
>>> Mike va3mw
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>>
>>
>