Hi Jim, You brought up a good point that I had not thought of and that is the voltage drop at the K3S itself. So I set up the voltage reading a the VFO B window and noticed that the voltage had dropped down to 12.1V when I keyed down, but the power supply said 13.7V at key down. So I shortened the power cable, by 32" and now it is 24" long. Now I see 13.1V at VFO B window and 100 watt on 160 meters and 105 watts on 6 meters. I increased the power supply voltage to 14V and now I see 13.3V at VFO B window, on key down and now 105 watts out on 160 and 110 out on 6 meters. So to make a long story short, the K3S will put out over 100 watts on 160 and 6 meters if your power supply voltage is at 13.8 volts and you keep the power cord short. The additional 32" of power cord dropped the voltage by 1 volt on key down. Everett N4CY
In a message dated 6/25/2019 7:50:32 AM Central Standard Time, [email protected] writes: I see the same output powers on my K3S. Key down voltage is 13.4 volts on the VFO B display at maximum power out. Elecraft offered to upgrade my PA chain for $100, but I'm not concerned about ~1dB and is within spec for 6m anyway. Glad that diode is in there. I tested its function once. _________ 73, Jim - N4ST -----Original Message----- From: [email protected] <[email protected]> On Behalf Of Don Wilhelm Sent: Tuesday, June 25, 2019 08:31 To: EVERETT SHARP <[email protected]>; [email protected] Subject: Re: [Elecraft] Low Power Output on 160 and 6 meters Everett, What is your power supply voltage during transmit at 100 watts as measured with the Alternate VFO B display? With a solid 13.8 volt power supply voltage, you should see no lower than 12.7 volts (there is a diode drop inside the K3). If lower, check the connections in the power cable for tightness. The K3 power cable should run direct from the power supply. Rigrunner and other DC power distribution boxes can be reason for excessive voltage drop. You can increase the power supply voltage up to above 14 volts to help - do not exceed 15 volts. 73, Don W3FPR On 6/24/2019 6:51 PM, EVERETT SHARP via Elecraft wrote: > I have three K3S and over the week-end I connected each of them to my Bird watt meter, with a Dummy load. Each of K3S were updated to the current Firmware and each had the 5 and 50 watt calibrations run. > > What I found was all 3 showed from 80 to 90 watts output on 160 meters > and on 6 meters I saw 75 to 90 watts. All other bands showed > typically > 105 to 110 watts. However, one of the K3S showed exactly 100 watts on all bands except for the lower power on 160 and 6 meters. > ______________________________________________________________ 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 Message delivered to [email protected] ______________________________________________________________ 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 Message delivered to [email protected]
