25 amp fusing isn’t a lot over overhead for a K3 with KRX3, KIO3a, P3 with the SVGA board and the PR6-10 preamp in play.
It all adds up. Use what is appropriate for your rig combination. 73, Rick NK7I Email spiel Czech corruptions happen > On Jul 21, 2021, at 10:33 PM, Ray <[email protected]> wrote: > > 30 Amp --- A little too High for me ! > I would use 25 Amp. > WA6VAB Ray K3 > > > From: Dave > Sent: Wednesday, July 21, 2021 7:43 PM > To: [email protected] > Subject: Re: [Elecraft] In Line Power Pole Fuses > > Hi, > > I am unsure what you are asking... If you are asking about fuse values, > I select values a bit above the max peak current I expect. For my K3 I > use a 30 amp fuse. > > If you are asking about voltage drop, and want to know what the K3 sees, > there is a built in volt meter in the K3, (see the manual), which will > show you the voltage at the K3, after all your fusing, and wiring. > > I always take my voltage readings at full output. I try and stay within > the limits Elecraft sets for voltage. If I am running low voltage on > transmit, I goose the power supply slightly, staying below the max > voltage rating Elecraft recommends when not transmitting at full power. > > The fuse(s) is/are probably not going to protect my radio-- if something > happens, (i.e., current draw in excess of 30 amps), the radio is > probably already broken. > > I use the fuse to reduce runaway thermal effects, (read that as fire), > on my power supply wiring in the event of a short to ground. I place > the fuse(s) as close to the power supply as my wiring will allow. > > 73, and thanks, > Dave (NK7Z) > https://www.nk7z.net > ARRL Volunteer Examiner > ARRL Technical Specialist, RFI > ARRL Asst. Director, NW Division, Technical Resources > >> On 7/21/21 7:18 PM, Peder Kittelson wrote: >> I have fused my Elecraft radio equipment with inline power pole positive >> and negative ATC car standard blade fuses. >> I am now doing an audit of the fuses in my system to make sure they are >> appropriate for the equipment they protect. I realize there are internal >> fuses in many cases, I prefer doubling my protection with inline external >> fuses as well. >> >> I have not read or heard anyone discuss the appropriate amperage ratings of >> fuses for my equipment or equipment in general. I would appreciate your >> recommendations on fuse sizes for these, as well as general approaches. >> >> Equipment and Specifications from Elecraft Manuals: >> >> 1. Elecraft K3s with 100 watt amp: Specs are 17-22 amps typical on >> transmit, recommended 25 amp power supply. >> >> 2. Elecraft KPA 500: Specs are PA Current 20 amp maximum. >> >> 3. Elecraft KX3: Specs are 1-2 amp typical current in transmit. >> >> One other important question. I have conquered much of the RFI in my radio >> room using power poles with extended thick Red and Black wiring wound >> around toroids. In this case the leads go from the Astron RS-35A to the >> K3s. I want to make sure there isn't too much drop in voltage over the >> extended toroid wiring. How can I best gauge what the K3s receives in this >> setup? The manual says it should receive 13.8 volts nominal, 11 volts >> minimum and 15 volts maximum. I think I am beyond the provided and >> recommended 5' power cable. I have not had any problems (that I know of). >> >> I do not have a desk full of electronic devices for evaluating this, so is >> there a simple way to be reasonably sure? >> >> 73 and thanks for your help, >> >> W7RPK, Peder >> ______________________________________________________________ >> 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]
