John, Thank you for your response. My original K3s test setup was per the manual: good quality dummy load (not the DL1 because of its 20 watt upper limit) with the ATU off. My high quality dummy load does not have a test point. After reading your results, I decided to take the DL1 as my "truth model". I found that the W1 display was 0.8 dB high and the K3s power display was 0.9 dB low. Each one was at the opposite end of the error budget. (sort of like winning the "losers" lottery). So, I set up the W1 to match the DL1 up to 20 watts and, surprise, the W1 TP voltage is now 4.87 volts. I don't have the W1 software and cabling installed yet. At that time I can fine tune all of this. It seems as though a consensus is building that the W1 manual specification of 4.5 volts is no longer correct, unless there is something "off" with the W1 internal algorithm. Good stuff. Thank you everyone for your comments and help.
-----Original Message----- From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of John Oppenheimer Sent: Thursday, December 31, 2015 7:22 AM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] W1 Hi Ed. The W1 DC voltage calibration resulted with incorrect reading with my W1. My hunch is that components have changed since Elecraft established the TP1 DC calibration voltage almost a decade ago. I have a KX3F with unchanged factory power calibration. Based on comments from Wayne, the KX3 is calibrated at 7.0 watts. My W1 TP1 voltage is 4.812 using a Fluke 87V Setting up a test bench with KX3 -> W1 -> DL1 Using W1 Utility to display W1 power: http://www.elecraft.com/software/W1/elecraft_w1_software.htm TP1 V = 4.812 KX3 power = 7.0 W W1 power = 7.02 DL1 V = 12.91 = 6.93 watts The W1 20 dB directional coupler does absorb power, at 7 watts, the directional coupler will absorb 0.07 watts. Adding 0.07 to the DL1 measurements equals 7.00 watts. John KN5L ______________________________________________________________ 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 g_e_lamb...@comcast.net ______________________________________________________________ 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
