[Elecraft] K3 shuts down

[Dave New, N8SBE]

Pete,

That advice is good for Elecraft rigs, and of course fine for this email 
list.

I'd just caution readers that come across this to realize that their 
rig's manual will tell them where to set the ALC for digital modes.  It 
does vary by rig manufacturer.

73,

-- Dave, N8SBE, Hamshack Hotline 590-0971, HamsOverIP 101018, 
AmateurWire 1348

On 2024-08-28 10:21, Pete Smith N4ZR wrote:
> 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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