Just finished building the KPA-100 for my S/N 2102 K2 (MCU v. 2.03D, KPA 1.06) The K2/100 does not display the correct 13.8 V power supply current (by taping Display) when it switches to HI POWER (>10 Watts). I used a DMM in series to accurately measure the PS supplied current while checking the K2 display at several power settings . Later, I also measured the KPA TP1 voltage which is the I sense input to the KPA-100 processor. For several power settings I got: PWR (Watts) - PS Current (DMM) Amps - K2 Current Display Amps - KPA/100 TP1 (mV) RX-0.4 - 0.44 - 0 <x-apple-data-detectors://0> 1.0- 1.72- 1.76 -0 5.0 - 3.3-3.3 - 0 10- 3.8 - 3.8 - 0 15- 4.5 - 1.01 - Not measured 20- 5.4 - 1.02 - 100 40 - 7.0 - 1.20 - 250 60 - 8.5 - 1.28 -380 80 - 9.5 - 1.41 - 500 100 - 10.3 - 1.48 - 580 111 - 10.8 - 1.54 - N/A The measurements were done at 40 m (7.100) at CW to a dummy load through KAT-100.
It seems to work fine a LO PWR (<11 Watts) but appears to have a scaling issue, when the PA switches On to HI PWR mode. According to the schem (p.61) I Sense is supposed to vary 0-5 V for 0-32 A, so the TP1 figures seem to be rather low. Is this a known issue? Is it possible that I have a failed U7 or Q5 ? Thanks! Ioannis -- Ioannis Kassotakis ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@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 arch...@mail-archive.com
