Of course! It's rated in MFJ WATTS. One regular watt = about 10 MFJ watts. Elecraft is one of the few companies making products rated in real watts.
On 1/27/2012 10:21 AM, Bill Gerth wrote: > Bert, > > In addition to the other suggestions you received, I'd suggest that > you make sure your dummy load is capable of this kind of key-down > power for that amount of time. I have an MFJ Dummy Load that is > called a 1.5KW Dummy Load but the chart on the back panel shows it is > only capable of around 120 watts for 60 seconds. It can only handle > 1.5 KW for less than 10 SECONDS. Some fan-cooled or oil-cooled dummy > loads might be OK for 500 watts of key-down for 1 minute, but my air- > cooled 1.5 KW Dummy Load is NOT. The non-inductive resistor gets very > hot and begins to smell even after relatively short key-down periods. > Your power change might be due to the dummy load changing its > effective resistance due to heating. > > Just a thought. > > 73, > > W4RK - Bill Gerth > Jefferson City, MO > [email protected] > > > > > On Jan 27, 2012, at 10:57 AM, [email protected] wrote: > >> Sorry if this has been covered before, but I can't recall that it >> has. Is >> there any reason why power output >> falls off over time? Here's what I did: using MMTTY, I "diddled" >> into a >> 50-Ohm dummy load for one minute. >> I initially had a power output of 525 Watts which went to 500 W >> shortly and >> went down to about 465 W >> when MMTTY "diddling" timed out. I repeated that process later, >> monitoring >> current and noted that it also >> went down over time...makes sense! >> But my question is WHY? I was under the impression that I needed to >> run the >> amp at 500 W on RTTY for >> optimum efficiency because in an earlier posting I noted that at 150W >> output (in BPSK31), the amp was very inefficient and the fan was >> pretty loud. If >> I can't derate the output and I can't run full output, what do I do >> with >> the KPA500 in the digital modes? >> >> Bert, N4CW >> >> -- Vic, K2VCO Fresno CA http://www.qsl.net/k2vco/ ______________________________________________________________ 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
