We should also know the power supply efficiency though as a switcher, I expect 90 plus percent.73 Doug EI2CNSent from my Samsung Galaxy smartphone. -------- Original message --------From: Andy Durbin <[email protected]> Date: 10/02/2020 16:58 (GMT+00:00) To: Doug Turnbull <[email protected]>, [email protected] Subject: Re: [Elecraft] QRO - KPA500 Failure
"I understand that efficiency decreases as one derates from the maximum of 1500W output.It surprises me that the power dissipated would peak at half power output or 750 Watts." I have no test data for the KPA1500 and will not speculate on the shape of the PA dissipation curves. All I have is data for one KPA500. For that one KPA500, and under the conditions tested, it's clear that PA dissipation is greater at half power than at full power. It would be easy to get a pair of data points for the KPA1500. Connect the amplifier to a known good 50 ohm load. Drive the amplifier to steady state 1500 W output Record PA current and voltage Drive the amplifier to steady state 750 W output Record the PA current and voltage Repeat on multiple bands if desired and report the results here. 73, Andy, k3wyc ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
