[Elecraft] QRO - KPA500 Failure

[Dave Cole]

Hi Rick,

I like your call sign!  :)

73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Volunteer Examiner
ARRL Technical Specialist
ARRL Asst. Director, NW Division, Technical Resources

On 2/6/20 1:07 PM, Rick Bates, NK7I wrote:
> Since the SWR is still nominal into the amp (as shown on your radio), 
> it's not likely the tuned input circuits (which is confirmed from no 
> output on all bands).
> 
> This points to the high power module.  Running low output power from it, 
> is far less efficient than pushing it hard (compare wattages consumed to 
> RF watts output delivered at different output levels); which may have 
> stressed the finals.  Ideally you run the previous stages at 
> low-moderate power for lower IMD, then punch it up with the amp.
> 
> The "HIGH SWR" fault you saw is then very likely the final signing QRT 
> SK.  You can confirm that with Elecraft wizards.
> 
> That module isn't hard to swap out, but it would be best (slightly more 
> costly) for the entire amp to visit it's parents, so that other updates 
> that may not have been done, can be done. Many of them, really matter.
> 
> While also not cheap in shipping and insurance (ask me how I know?) that 
> is often the better choice.
> 
> Rick, NK7I
> 
> On 2/6/2020 12:54 PM, Michael Walker wrote:
>> Amps making noises like that usually mean you have to take the covers 
>> off.
>>
>> They are easy enough to repair if you are so inclined.  If not, then you
>> will need to contact Elecraft support and odds are you will have to 
>> send it
>> home for a Spa day.
>>
>> Mike va3mw
>>
>>
>> On Thu, Feb 6, 2020 at 3:35 PM Jim Brown <jim at audiosystemsgroup.com> 
>> wrote:
>>
>>> On 2/6/2020 12:15 PM, Jim Mullen wrote:
>>>> Any pointers of where to start looking?
>>> 1) What SWR does the rig see with the amp off?
>>> 2) Make notes of any error messages given by the KPA500 display.
>>> 3) Call Elecraft Support
>>>
>>> 73, Jim K9YC
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