[Elecraft] KXPA100 70 to 80w out Max with KX3 drive at 15W???

[Bert]

Kyle,
Do you have another radio or load so you can draw around 20 amps from 
the PS
and determine that it's working OK?
Bert VE3NR


On 2022-10-18 10:55, Kyle Krieg wrote:
> PS is showing 12.7A at 13.9V output on full keydown.  That is with the KX3
> powered from the back of the KXPA100.
>
> Kyle
>
> That power supply should be adequate, if it's working properly.
> Bert VE3NR
>
>
> On 2022-10-18 9:26, Kyle Krieg wrote:
>> * Astron SS-30M-AP
> *>>>* What Astron power supply are you using?
> *>>* John KK9A
> *>>* Bert ve3nr wrote:
> *>>* It seems your power supply doesn't have the capacity to deliver enough
> *>* current.
> *>* At 100W output the current draw from the PS should be closer to 20 Amps.
> *>* Bert VE3NR
> *>>>* On 2022-10-17 15:03, Kyle Krieg wrote:
> *>>* * Hello all,
> *>* *>>* I used my KXPA100 this past weekend and noticed some lower than normal
> *>* *>* output on both SSB and CW.  Sitting on the bench today I've noticed that
> *>* *>* I'm only putting out around 70 to 80W max where I used to push close to
> *>* *>* 100w in previous outings.
> *>* *>>* I tested the drive of the KX3 to find that to be 15W max, so
> that is good
> *>* *>* and spot on.  I've checked the power setting output on the KX3
> to drive up
> *>* *>* to 110W.  I've powered the KX3 from both the back of the amp and an
> *>* *>* external power supply with the same results.  The KXPA100
> power is from an
> *>* *>* Astron power supply.  On key down it gives it about 11A's of power.  DC
> *>* *>* doesn't drop below 13.5 on key down with the amp on while it's
> pushing the
> *>* *>* 72 W output. I've hooked up the KXPA100 utility and everything
> seems to be
> *>* *>* working correctly with no faults found.  Short jumpers were used (less
> *>* *than
> *>>* * 2ft) with quality cable from back of the KXPA100 to the Bird wattmeter
> *>* *then
> *>>* * to a HF dummy load.  SWR is flat on all bands.
> *>* *>>* Here is the power output per band on CW keydown.  The KX3 display is
> *>* *>* showing 110W output.
> *>* *>>* 160m : 80w
> *>* *>* 80m : 78w
> *>* *>* 60m : 73w
> *>* *>* 40m : 72w
> *>* *>* 30m : 80w
> *>* *>* 20m : 78w
> *>* *>* 17m : 92w
> *>* *>* 15m : 85w
> *>* *>* 12m : 80w
> *>* *>* 10m : 80w
> *>* *>* 6m : 76w
> *>* *>>* These numbers match between the windows utility and Bird wattmeter.
> *>* *>>* Thoughts?
> *>* *>>* Kyle*
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