[Elecraft] K3 shuts down

[Pete Smith N4ZR]

I think many of us do this, but months ago I also started following 
advice on the WSJT reflector and made sure to set my audio so that the 
ALC indication peaked at 4 bars or just occasionally tickling the 5th.  
Said to clean up the FT8 signal.

73, Pete N4ZR

On 8/28/2024 10:12 AM, Dave New, N8SBE wrote:
> Also, for digital modes, I run my equipment at half power, max.  So, 
> for a 100W XCVR, I run it at 50W.
>
> This serves two purposes.  One, it's easier on the PA, and two, it 
> leaves a 3dB 'overhead' for the digital mode, and less likelihood of 
> distortion getting into your TX signal.  This has been SOP for many 
> years for digital modes.
>
> A difference of 1/2 S-unit on the receiving end will generally be 
> unnoticed, and your equipment will thank you, as well as any receiving 
> nodes that may not be able to decode your signal if you are pushing 
> your equipment to its limits.
>
> 73,
>
> -- Dave, N8SBE, Hamshack Hotline 590-0971, HamsOverIP 101018, 
> AmateurWire 1348
>
> On 2024-08-28 07:24, G4GNX wrote:
>> My K3S did this a couple of months ago - 40m SSB - 100W. I restarted 
>> it and it continued for nearly another month before switching off 
>> again. It did it a couple of times more over a week or so, before 
>> finally turning off and refusing to turn on again.
>>
>> On investigation, I realised that I had “temporarily” connected the 
>> K3S power cable to a distribution box, using PowerPoles - bad move. 
>> When tracing the cable routing, I pressed against one of the 
>> PowerPoles and the radio came back on again. I found it impossible to 
>> pull the PowerPoles apart, which was due to the plastic covers being 
>> badly distorted by heat. I eventually got round to pulling the 
>> PowerPoles apart by force and unfortunately the + connector flew in 
>> the air and I haven’t found it yet. 😀
>>
>> However, the contact in the dis-box looks suspiciously like it’s 
>> gotten hot and coupled with the other “evidence” I conclude that the 
>> contacts deformed under heat caused by high current spikes (SSB).
>>
>> Also, my IC-9700 (although connected to a different PSU - via 
>> PowerPoles) did the same thing, but unlike the K3S, it just rebooted 
>> itself.
>>
>> I have completely rewired all of the high power cables in my shack 
>> directly back to the PSU (Sharman Multicom - 60A) and I’ve had no 
>> more problems.
>>
>> In your case, you’re running 100W for longer periods and that is one 
>> possible cause of a premature breakdown. You could save yourself a 
>> lot of trouble, by examining all of the power connections, including 
>> the PowerPoles on the K3 itself.
>>
>> 73,
>> Alan - G4GNX
>> South Coast UK
>> Elecraft K4D / KPA500 / KAT500 / IC-9700
>>
>>
>>
>>
>>> On 28 Aug 2024, at 03:30, Glenn Thorne <kd0q.glenn at gmail.com> wrote:
>>>
>>> Just tonight my K3 with KPA3 running 100 watts shuts down during 
>>> digital
>>> transmissions.  It appears that it happens after the PA temp is 47 C.
>>> Maybe the first time it hits 48 C?
>>>
>>> I checked the KPA3 FN1 - 4 settings and it appears that the fans work.
>>>
>>> At what PA temps should the fans come on?  Increased speed?
>>>
>>> Any ideas where to start troubleshooting will be appreciated.
>>>
>>> Glenn - KD0Q
>>
>>
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