Re: [Elecraft] KPA500 - key down current on CW

2011-11-28 Thread Ron D'Eau Claire
Like virtually all "fixed tune" or "no tune" rigs, the efficiency and so current demand varies widely with SWR since the output filters cannot be adjusted to compensate. (There was an advantage to "dipping the final" in the old rigs - it kept the efficiency up.) Also, the efficiency and so current

Re: [Elecraft] KPA500 - key down current on CW

2011-11-28 Thread Roy Morris
There is a 4 watt discrepancy between the 39 watts dialed in the K3 and the 43 watts that is shown on my PowerMaster meter. The PowerMaster coupler is attached directly to the output of the K3 (using a double male connector) with a 5 foot length of RG8 coax to the input of the KPA500. The Pow

Re: [Elecraft] KPA500 - key down current on CW

2011-11-28 Thread Brian Alsop
Hmm, this works out to an efficiency of 87%! Not sure I believe that. 73 de Brian/K3KO On 11/28/2011 20:34, Roy Morris wrote: > My KPA500 is as follows: > 500 watts indicated on LEDs > Current: 10.3 Amps at 500 watts indicated on LEDs > Idling current: (key down - no modulation) 400 ma > Voltage

Re: [Elecraft] KPA500 - key down current on CW

2011-11-28 Thread Roy Morris
My KPA500 is as follows: 500 watts indicated on LEDs Current: 10.3 Amps at 500 watts indicated on LEDs Idling current: (key down - no modulation) 400 ma Voltage at 500 watts: 59.8v Power as indicated on display: 530 watts Power dialed in on K3: 39 watts Power source: 240v Freq: 3.781 Mhz SWR: 1:1

Re: [Elecraft] KPA500 - key down current on CW

2011-11-28 Thread David Ferrington, M0XDF
Thank you very much, just what I wanted to know. 73 de M0XDF -- When a distinguished but elderly scientist states that something is possible he is almost certainly right. When he states that something is impossible, he is very probably wrong. -Arthur C Clarke, science fiction writer (1917-2008)

Re: [Elecraft] KPA500 - key down current on CW

2011-11-28 Thread Jim Sheldon
On my resonant Tribander with 1.2.1 SWR and the bargraph indicating 500W output, mine pulls 11.9 amps with the HV measuring 62.5 volts for a drain input power of 743.75 watts. The amp is being run on a mains voltage of 240. Drive power from the K3 indicates 28 watts. Jim - W0EB > Purely as a

[Elecraft] KPA500 - key down current on CW

2011-11-28 Thread David Ferrington, M0XDF
Purely as a matter of interest, how much current does the KPA500 draw on CW key down? 73 de M0XDF (K3 #174, P3 #108, KX3 #???) -- He who asks is a fool for five minutes, but he who does not ask remains a fool forever. -Chinese proverb ___