Diode voltage drop is approximately 0.7v per diode Sent from my iPhone
> On Feb 26, 2019, at 2:16 PM, Jack Brindle via Elecraft > <elecraft@mailman.qth.net> wrote: > > Be sure to use a DVM external to the K3 to measure the voltage at the K3. The > input protection diode in the K3 will cause some drop (1/4 to 1/2 volt > perhaps). What this means is that the K3 meter will always show less voltage > than is really present at the transceiver supply input. > > > 73! > Jack, W6FB > >> On Feb 26, 2019, at 9:37 AM, mjpilgrim <mpilg...@bellsouth.net> wrote: >> >> Well, i have received many helpful replies both publicly here and in private >> emails. Thanks to all for those ideas brought forward. >> >> What I've gleaned to be most useful from your responses has been the >> suggestions to investigate the power cord with power poles connecting the K3 >> to my switching power supply. Per those inputs I've fabricated a shorter >> (5') cable and insured that I used the crimp terminals rated at 30 AMPS. >> The initial result has been a reduction of about 30% of my measured voltage >> drop (now 13.6 Volts in standby to 12.5V when key down 100W CW........ >> previously the drop was to 12.0)............... Some background info. is >> that the original observation of a voltage drop occurred as the K3 was >> connected to my minimal-sized Solar Power supply. After extensive >> investigation, additional hardening in the wiring, and replacement of a >> suspect imported power distribution strip, I was convinced there was no >> voltage drop evidenced there. The battery voltage measured at the input to >> the referenced DC power distribution strip did not waver under key down >> tests with the attached K3............. There remained however, the >> above-mentioned voltage drop displayed in the K3 metering. >> >> i plan to rebuild the afore-mentioned 5' power cable, this time soldering >> the power pole lugs rather than trusting crimped connections. My suspicion >> that the power cable is suspect, so i plan to address those curiosities >> before moving on to other possible cause. >> >> Thanks again for your continued ideas and suggestions. >> Regards, >> Mike, K5MP >> >> >> >> -- >> Sent from: http://elecraft.365791.n2.nabble.com/ >> ______________________________________________________________ >> 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 > > ______________________________________________________________ > 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 ______________________________________________________________ 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
