A variation of 0.2 volts at 13.6V is less than 1.5%. I wonder how accurate the voltage measuring circuitry is in the K3?
73, Bob Bob Nobis - N7RJN [email protected] > On Nov 24, 2015, at 15:39, Ron D'Eau Claire <[email protected]> wrote: > > Joe, as a point of reference, I have a K3 with the bottom off on the bench > so I checked the voltage at the terminals of the APP connector on the RF > board with two DMMs. One DMM says 13.63 and the other says 13.66. The FP > display says 13.4. > > It sure looks like they aren't compensating for the 0.2VDC drop across the > reverse protection diode. > > 73, Ron AC7AC > > -----Original Message----- > From: Elecraft [mailto:[email protected]] On Behalf Of Joe > Subich, W4TV > Sent: Tuesday, November 24, 2015 9:31 AM > To: Robert Nobis; Elecraft > Subject: Re: [Elecraft] K3 Voltmeter calibration ... > > >> You could easily drop 0.2 volts in the cable depending how long it >> isand the gauge of the wire. > > Not in six feet of #10 wire at 1.5A. Even if it were #12 the voltage drop > should be less than 0.03V (1.62 Ohms/1000 feet for #12). > > 73, > > ... Joe, W4TV > > > On 11/24/2015 10:39 AM, Robert Nobis wrote: >> Joe, >> >> How long is your power cable from the RS-35A to your K3, and what gauge > wire is used? You could easily drop 0.2 volts in the cable depending how > long it is and the gauge of the wire. >> >> 73, >> >> >> Bob Nobis - N7RJN >> [email protected] >> >> >>> On Nov 24, 2015, at 08:06, Joe Subich, W4TV <[email protected]> wrote: >>> >>> >>> OK, I'm sure I am overlooking something simple but I can not find (or >>> remember) how to calibrate the voltage display in the K3. >>> >>> I had to repair one of my Astron RS-35A power supplies for the first >>> time in 30 years (one of the diodes shorted) and when I put it back >>> on line I decided to double check the K3 Volts display against the >>> actual output of the supply. The K3 is reading about 0.2V less than >>> the supply voltage. >>> >>> I've been over both the K3 Owner's Manual and the K3 Assembly >>> Instructions but can't find any reference to calibrating the voltage >>> display. >>> >>> 73, >>> >>> ... Joe, W4TV >>> >>> ______________________________________________________________ >>> 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] > > ______________________________________________________________ > 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]
