[Elecraft] KS3 internal 100 watt amp (K3S/100) is intermittent

[K1dj]

Yes, exactly the same, Frank.

Sent from my iPad

> On Aug 1, 2019, at 5:44 PM, donovanf at starpower.net wrote:
> 
> Hi Rich,
> 
> Do the same error conditions occur when the radio is connected directly
> to a dummy load?
> 
> 73
> Frank
> W3LPL
> 
> From: "Richard Hoffman, K1DJ via Elecraft" <elecraft at mailman.qth.net>
> To: elecraft at mailman.qth.net
> Sent: Thursday, August 1, 2019 2:16:31 PM
> Subject: [Elecraft] KS3 internal 100 watt amp (K3S/100) is intermittent
> 
> Rig:  K3S (100W with internal ATU), s/n 11064, P3, KPA500, KAT500, into SteppIR 3-el with 30/40 loop or wire dipoles/inverted-V's.
> 
> Problem:  My K3S 100 watt internal amplifier unit (K3S/100) has become intermittent.  
> 
> It first happened yesterday while I was running 100W on FT-8.  [I have done this hundreds of times, sometimes for lengthy periods, over the past 18 months with no problems.]
>  Suddenly, my power output dropped to zero, and my received signals audio and P3 display also suddenly went quiet.   
> 
> After some fiddling around, I figured out that if I reduced the K3S power to 10-12 watts, both transmit and receive came on again — leading me to conclude that it must be my 100W amp unit that had dropped out.  
> 
> I rebooted the rig and the 100W internal amp unit kicked back on.  So I was hoping I had just triggered a protective circuit which had reset.   The rig worked fine at 100W for a subsequent hour-long multi-band CWOPs CWT CW session at 100W.  Then, however, a few minutes into the next CWT session hours later, the same thing happened again.  Power output suddenly dropped from 100W to 0, and received audio and a P-3 screen filled with many medium to strong CWOPs signals simultaneously went quiet.  
> 
> I reduced the power on the K3S down to 10W, and both transmit and receive worked again, but only at low power.
> Please pass along any helpful suggestions, and thanks!
> Richard Hoffman (Rich), K1DJScituate, MA
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