[Elecraft] K4D - KPA500 Fault Question + wish

[email]

On 4/24/22 15:06, Jack Brindle wrote:
> Steve;
>
> Use the KPA Utility to see the KPA faults. Access is under the Configuration tab, then click on “Display Fault Table”.
> You can also save it to a file for view in a text editor, or if we ask for it, send it to tech support for analysis.

Thanks, I knew I had seen the fault table some place.

What was there were early learning and adjusting (tuning) an antenna 
that needed a 4:1 balun to match.

I will keep the utility on to see if it captures future "issues".

I DO like and USE the the KAT500 utility as it provides NICE antenna 
status info like SWR with/without bypass.

> The FAN CTL sets the minimum fan speed. It works in both OPER and STBY modes.Yes, it just would be nice if putting into standby, that when cooled, 
> it would quiet down. Yes, I can do it manually.
>
> And, like all amplifiers, the KPA500 has a design point where efficiency is best. Outside this design point (both high and low),
> efficiency will fall off and you will find that the amp will run hotter. This is what you may have found. Remember, the PSK modes
> tend to keep transmission active for very long times, and can really tax an amplifier. Amazingly, you may be better off running
> the amp at higher power than yo were using to lower the stress on the PA. I am sure there are several folks on the reflector who
> Can explain this very well.Yes, that maybe the extra heat. Thak you. I won't pull things apart, 
> just yet...
>
> The amplifier will protect itself(IT DID, nice!)  if the PA temperature goes above 90 degrees Celsius. That is the point where you will see a fault.
> The fault log actually records the temperature when the fault occurred in its data field, which is displayed in a hexadecimal value.
>
> Try looking at the fault log to see what happened on the KPA side. If you have questions, just ask.
>
> 73,
> Jack, W6FB
>
> Thanks, Steve WB3LGC
>> On Apr 24, 2022, at 1:03 PM, EMAIL<email at nr3i.org>  wrote:
>>
>> Yesterday I got a fault message on the K4 screen. It disappeared before I could see it fully, but I did get "tighten heatsink screws".  The fan was working as its speed was speeding up and the KPA500 temp saw about 60+C (it may have been higher).  I was running 100 watts PSK31.  The KPA500 did switch to STBY (I think).
>>
>> I can not find any record of what the message was.  I can not find "heatsink screws" referenced in the K4, KPA500 or KPA1500 manuals.  Both the K4 and KPA500 are factory built.
>>
>> PSK31 has a longer duty cycle than FT8 and I was running FT8 at higher power with out the amp temp going above 60C, earlier.  I switched to barefoot and ran 80W PSK31 without issue.
>>
>> Question 1) Before I take the KPA500 apart, is this a problem or just duty cycle?  I would think the KPA500 would be able to handle 100W key down.
>>
>> Question 2) I saved the K4 backup and diagnostic logs to USB disk (the next day).  I could NOT find anything that looked like the error messages.  I find many messages disappear before I get a chance to read them.
>>
>> Wish 1) KPA500 add FAN CTL for both OPER and STBY or set STBY to run at NOR and OPER to be adjustable.
>>
>> Wish 2) K4, allow checking date/time for all past error messages.  I may have had a KPA500 over temp message while long winded on SSB (but only 200W)?
>>
>> Wish 3) K4, HOLD error messages until "confirmed".  Messages like KPA500 on/off (info) only need to be short time (??), but if away (maybe confirm).  Either way "this" will be an issue for  the contesters, so have a way to save for later recall, as in write to USB if one is installed.  Fn could write to USB disk with time stamp?  OR, are there documents on how to read the diagnostic logs?
>>
>>
>> 73, steve WB3LGC
>>
>> I will also send to support if no one has a good idea about the fault.
>>
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