KPA100 (or K2) Power control

[Bill N2BC]

I'm having a difficulty with the power control in a freshly built
KPA100.   When I set the power to 50W then key up (TUNE), I get appx 25W
(indicated on the K2 and external wattmeter).  If I barely move the
POWER control on the K2 output will jump to 50W indicated on both the K2
and wattmeter.  Each TUNE cycle is the same.

I'm not sure if the problem is in the KPA100 or my K2, as the K2 is not
very 'stable' either.  With the KPA100 disabled I set the K2 to say 5W,
then enter TUNE, I get appx 7W output (indicated on K2 and wattmeter),
minor touch on the POWER control will drop the power to 4W, exit TUNE
and it says 5W.  It behaves this way with the KPA100 set OFF or with no
PA PS or completely disconnected.

Confused?  Well, I am!   The bare bones K2 overshoots it power setting,
with the KPA100 it under achieves.  :-)

All of my testing has been done with a known good dummy load.  The
'problem' is not band sensitive.

How 'stable' should the K2 POWER settings be - if I set it to 5W should
I be seeing 5W indicated on the K2?  I thought that under a good load
condition the firmware would 'match' the requested power and actual
power within a few tenths or so.

I figure the K2 needs to be fixed before I fiddle more with the KPA100 -
yes?   Now the hard questions... what, where, why is the sky blue?
(wanted to have one easy question!).

Thanks all

73, Bill   N2BC
K2 #5290





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[David A. Belsley]

Read the manual, Bill.  When you push Tune, the power out is limited  
to 20 watts.  You can bypass this feature by pushing Tune and Display  
at the same time. Read the manual, Bill.

best wishes,

dave (Read the manual, Bill), w1euy




On Feb 6, 2006, at 6:42 PM, Bill Coleman N2BC wrote:

> I'm having a difficulty with the power control in a freshly built
> KPA100.   When I set the power to 50W then key up (TUNE), I get  
> appx 25W
> (indicated on the K2 and external wattmeter).  If I barely move the
> POWER control on the K2 output will jump to 50W indicated on both  
> the K2
> and wattmeter.  Each TUNE cycle is the same.
>
> I'm not sure if the problem is in the KPA100 or my K2, as the K2 is  
> not
> very 'stable' either.  With the KPA100 disabled I set the K2 to say  
> 5W,
> then enter TUNE, I get appx 7W output (indicated on K2 and wattmeter),
> minor touch on the POWER control will drop the power to 4W, exit TUNE
> and it says 5W.  It behaves this way with the KPA100 set OFF or  
> with no
> PA PS or completely disconnected.
>
> Confused?  Well, I am!   The bare bones K2 overshoots it power  
> setting,
> with the KPA100 it under achieves.  :-)
>
> All of my testing has been done with a known good dummy load.  The
> 'problem' is not band sensitive.
>
> How 'stable' should the K2 POWER settings be - if I set it to 5W  
> should
> I be seeing 5W indicated on the K2?  I thought that under a good load
> condition the firmware would 'match' the requested power and actual
> power within a few tenths or so.
>
> I figure the K2 needs to be fixed before I fiddle more with the  
> KPA100 -
> yes?   Now the hard questions... what, where, why is the sky blue?
> (wanted to have one easy question!).
>
> Thanks all
>
> 73, Bill   N2BC
> K2 #5290
>
>
>
>
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com

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