On Fri,8/21/2015 11:52 AM, Richard S. Leary wrote:
RX 13.9V @ 1.15A TX (100W CW) 12.6V @ 19.62A Readings from K3 VFO "B" display of "V" and "A"
The difference includes the IR drop in the red/black power cable between the power supply and the K3. Some quick arithmetic. #10 AWG is 1 milliOhm per foot. A 6 ft cable would be 12 m Ohms (two conductors), so .216V drop at 18A. With #12, it's .35 volts, .54 volts. Subtract the numbers for your cable (factoring in the length) from the difference, and that's the sag in power supply (and, of course, resistance internal to the K3).
A better way to measure the sag in the PSU is with a digital voltmeter connected across it's output terminals.
73, Jim K9YC ______________________________________________________________ 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]
