FW: [Elecraft] K2 Odd Power issues
Evidently the wattmeter is not a problem. The KAT2's power meter seems fine (eg, believable). I checked with a 200MHz bandwidth scope and the results are shown below. I'll dig around the transformers a bit. What's the current thinking on the 160 inefficiency? Dan / WG4S / K2 #2456 K4ZM sez: Don't overlook the fact that most wattmeters have a roll off of accuracy when you get ot the 24/28 MHz frequencies. They tend to indicate a lower than actual output. Freq KAT2 Amp O'scope Calc 1.8 9.9 4.7 3.613.0 3.5 13.9 3.0 4.116.8 7.0 14.4 2.9 4.116.8 10.1 13.1 3.0 3.814.4 14.0 12.9 2.7 3.613.0 18.1 14.2 3.0 3.713.7 21.0 11.6 3.1 3.210.2 24.9 9.3 2.5 2.8 7.8 28.0 5.8 2.3 2.4 5.8 O'scope figures are p-p/2 at 10X. Calc is (Scope * 7.07)^2 / 50 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] K2 Odd Power issues
Dan: Depends upon which MODE you're in when you set power. Po28 only is active in modes other than CW. 73, Tom N0SS At 07:23 AM 12/20/04, Dan Barker wrote: I'm aware of that setting, but the symptom is on 24 only, not on 28. Very odd. Also, I didn't remember that it was for 12 also. So, I set the Po28 to 15. Now both 24 and 28 show 15.2 as max requested. I set it back to 10. Still both 24 and 28 show 15.2 as max requested. I'm guessing the firmware got lost, at some point, and toggling Po28 fixed it. Now the display is believable, and I've got a couple transformers to inspect for the low power out on the higher bands. Very interesting result. Dan k4zm sez: In your Secondard Menu of the firmware there is a setting called "Po28" it comes defaulted to 10 watts and this controls the maximum output on 12 and 10 meters. Sent via the WebMail system at visioncomm.net ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] K2 Odd Power issues
I'm aware of that setting, but the symptom is on 24 only, not on 28. Very odd. Also, I didn't remember that it was for 12 also. So, I set the Po28 to 15. Now both 24 and 28 show 15.2 as max requested. I set it back to 10. Still both 24 and 28 show 15.2 as max requested. I'm guessing the firmware got lost, at some point, and toggling Po28 fixed it. Now the display is believable, and I've got a couple transformers to inspect for the low power out on the higher bands. Very interesting result. Dan k4zm sez: In your Secondard Menu of the firmware there is a setting called "Po28" it comes defaulted to 10 watts and this controls the maximum output on 12 and 10 meters. Sent via the WebMail system at visioncomm.net ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] K2 Odd Power issues
I was tweaking up my Band Pass filters the other day, and noticed something weird. If you advance the Power Requested knob fully clockwise, it reads 15.2 watts on all bands except 12 meters. For 24 megacyccles per second, it shows 10.0 watts. The K2 (#2456 + A:B, etc.) produces over 10 watts (but not 15.2!) everywhere below 24kkcps, but this behavior of the POUT display has me baffled. Since I always run 5 watts anyhow, I don't see any operational issue, but I sure am curious. Also, power seems a bit low on 10 (and maybe 12) meters, and current a bit high on 160 - I'd not noticed due to the above mentioned self-imposed 5 watt limit. Any ideas out there? Dan / WG4S / K2 #2456 Raw data (Power from the KAT2 in CALP mode, Heathkit Cantenna). Power: Car battery on 16 guage wire (My bench supply peaks at 3A). kkcps Pout (max CW) 1.89.9 (High-current annunciator, CAL Cur at 4.0) 3.5 13.9 7.0 13.5 10.1 12.9 14.0 13.8 18.1 14.1 21.0 11.4 24.99.6 (Software limited or hardware? Hu.) 28.05.8 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
