/*I had the same issue which appeared out of no were after a update in firmware I think it was because it was not happening when I first built the Amp. When my radio was new it did 140 watts output a later firmware update cut this back to 110 watts when the over shoot of power to the amp on the first dit started to appear the Amp would do a soft fault and fold back to 250 or 300 watt output if I kept sending it would build back to full power out put 500 watts.

What I was seeing happening was the K3 would on the first dit of the day (cold start for the fist operating session ) would spike to 140 watts then fold back to 110 watts this is without the amp in operate I would see the K3 power spike 140 watt on the meter display on the Amp and the K3 if the Amp was in operate the 140 spike would cause an instant soft fault ((high drive pwr ) or some such message on the KPA500 display causing the pwr output to fold back to 250 watts or so then build back up to normal 500 watt output.

I think there might be a software code error which is allowing the K3 to over shoot power out at the initial touch of the key.

The strange thing is it only happen when I first started up operation I could run the amp for a hour rag chew and it never happened again.... but shut down the radio and amp come back latter this issue would be there again. I have peak hold setting selected on both the Amp and K3 this spike is very fast but shows up if peak hold is selected.

Another poster stated he played with the ALC THR menu setting on the KPA500 setting the number to 150 and this fixed the issue. I did the same thing to my setup For most bands the ALC THR is set 150 but on 1.8 mhz my setting is 210
on 3.5 my setting is 129 on 54. mhz is also 129.

This hides the over shoot on power from my K3 on the first dit of the day even if I have the power set to 100 watts not full right the over shoot still is there in the radio..... and yes the drive power was set correctly for the Amp. I have not called service on this issue as the work around is working the issue is with the K3 power control which is not there on the first dit, after start up.

Regards
Art
ka9zap
*/
On 6/7/2013 10:09 AM, Arie Kleingeld PA3A wrote:
Hi all,

My K3 and KPA500 combo seems to overshoot the powersetting at the beginning of a morse dot or dash. It happens with all morse code, not only the first dot or dots.

Pwr at start of dot: abt 570 W, steady state pwr 520 W. It does show on my peak reading measurerents and the 550W led on the KPA lights with every dot/dash. Holding the key 440W led is off, so that confirms my other measurements.

Checking the manuals does not help me at this time.

Here's the setup:
K3 #1255 with all HW mods and FW 4.60 / 2.80, running 33W on 12m
TX ALC On (normal)
EXT ALC Off

KPA500 #1497, brandnew, FW 1.23
ALC THR 210 (default)

KAT500: BYP

K-line is connected via the elecraft aux cables.




So.....What did I miss, or is this normal?


73
Arie PA3A
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