[Elecraft] K-3 Power Output

[Dauer, Edward]

 I had a similar, if not worse, problem during the CW DX contest a week ago.  On Day 1 everything worked perfectly, including 15 meters.  On Day 2 everything except 15 meters worked perfectly.  On that band the KPA1500 would show a full-scale over-range power output and then shut itself down.  The SWR was never more than 1.2:1.  In standby mode everything was just right.  No problems.

Thinking the amp might have been at fault, I reloaded the firmware, to no effect.  Numerous tries with the power on the K3 set as low as 5 watts using the front panel control resulted in the same overdrive fault.  Same thing whether I keyed the rig, spoke into the mike, or pressed "tune."  The display on the KPA said 72 watts input when it faulted.  

No problem on any other band.  I noticed, after a while, that the power output indicator on the K3 display on key down would very briefly jump to near the top of its range and then quickly fold back to nearly zero, probably the result of the amp sending it a significant ALC voltage.  And again, same thing no matter where the K3 power control was set.  Shut the rigs off, went out for a walk and a ponder, came back, turned 'em on, and all was good again.

I would like not to have that happen during the SSB portion this coming weekend.  Any ideas, anyone?  Is it the K3 misbehaving?  The KPA sending the K3 the wrong status info?  The operator doing something wrong?  Hacking by contest competitors? (hardly necessary)

Ted, KN1CBR



    Message: 2
    Date: Sun, 24 Feb 2019 20:07:13 +0000
    From: Jim McCook <w6ya at cox.net>
    To: Elecraft Reflector <elecraft at mailman.qth.net>
    Subject: [Elecraft] K-3 Power Output
    Message-ID: <8dae2ee7-4daa-1493-bb2d-835138de84c1 at cox.net>
    Content-Type: text/plain; charset=utf-8; format=flowed
    
    One of the features I liked with the K-3/KPA-1500 combo was having power 
    setting in the K-3 remain at 100w for barefoot or amplifier STBY 
    position.? When the KPA-1500 was set to OPER, the power from the K-3 
    reverted to the low drive level, such as 32w.? Now it remains at one 
    power setting either way.? I can't figure out what caused that change.? 
    The cable between both units is secure in place and they are 
    communicating with each other.? As I tune the K-3 the KPA-1500 tuner 
    settings change normally.? Any idea why this changed?? -Jim
    
    
    ------------------------------
    
    Message: 3
    Date: Sun, 24 Feb 2019 14:10:57 -0600
    From: Bob McGraw K4TAX <rmcgraw at blomand.net>
    To: elecraft at mailman.qth.net
    Subject: Re: [Elecraft] K-3 Power Output
    Message-ID: <70c15173-ff5d-d9a2-c2b3-a1aad195938f at blomand.net>
    Content-Type: text/plain; charset=utf-8; format=flowed
    
    Check the Power Set Per Band setting in the K3 config menu. Should not 
    be set to NORmal.
    
    
    73
    
    Bob, K4TAX