[Elecraft] KPA1500 Drive Power

[K9MA]

Yes, it does sound like a solid-state thing.  Not enough negative feedback?  It may be a reason NOT to run the fans continuously: Once it reaches 60 C, the fan control keeps the temperature fairly stable. 

73,
Scott K9MA 

----------

Scott Ellington

 --- via iPad

> On May 31, 2018, at 10:10 AM, Bill Stravinsky <k3wjv at yahoo.com> wrote:
> 
> Yup, as the temp climbs the output drops some.  Even though I'm glad I got the solid state amp I still prefer tubes, hi.  The drop is anywhere between 100 to maybe 300 watts.
> I never really noted the exact numbers.
> 
> Bill
> K3WJV
> 
> p.s. I'm thinking its a normal solid state thing.
> 
> On Wednesday, May 30, 2018, 4:23:47 PM EDT, K9MA <k9ma at sdellington.us> wrote:
> 
> 
> I'm using the K3 with the Elecraft interface cable.  I've noticed the 
> the CW drive power required by mine varies considerably, both with 
> temperature and SWR.  If I set the K3 output for a KPA1500 output of 
> 1500 W output initially, the output will drop to perhaps 1100 W when the 
> temperature stabilizes at around 65 C.  (I've ruled out any change in 
> antenna impedance, etc.)  A similar change occurs if the SWR goes from 
> 1:1 to 1.2:1 when changing frequency or switching antennas.  I haven't 
> changed the ALC from the default setting.  Has anyone else noticed this?
> 
> 73,
> 
> Scott K9MA
> 
> -- 
> Scott  K9MA
> 
> k9ma at sdellington.us
> 
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