[Elecraft] KPA-1500 Efficiency As A Function of Input Power

[K9MA]

Perhaps because the power supply is the limiting factor. 

Scott K9MA 

----------

Scott Ellington. K9MA

 --- via iPhone

> On Aug 17, 2018, at 8:43 AM, "john at kk9a.com" <john at kk9a.com> wrote:
> 
> So why do most RTTY users run their amps at reduced power?
> 
> John KK9A
> 
> 
> From: Charlie K3ICH
> Date: Fri Aug 17 09:24:18 EDT 2018
> 
> 
> I really do NOT understand why this data is so surprising.
> It all seems to me to be perfectly normal with the amplifier's highest
> efficiency occurring at near max output.
> Which curiously, I would assume,  is the way the amp was designed.
> 
> Think zero output with zero drive = zero efficiency.
> Apply some drive, read some output and the efficiency goes up from there.
> 
> 73, Charlie k3ICH
> 
> 
> 
> 
> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net <elecraft-bounces at
> mailman.qth.net> On
> Behalf Of john at kk9a.com
> Sent: Friday, August 17, 2018 8:57 AM
> To: elecraft at mailman.qth.net
> Cc: charles at k5ua.com
> Subject: [Elecraft] KPA-1500 Efficiency As A Function of Input Power
> 
> Interesting data, Charles.  I assumed that running the KPA1500 (or KPA500)
> at lower power would keep the fan from running as much. I knew that
> efficiency changed with output power but I did not expect that it was this
> significant. If your data is correct there is 1000++ watts of heat to
> dissipate no matter what power level you use.
> 
> John KK9A
> 
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to k9ma at sdellington.us