Re: [Elecraft] In Line Power Pole Fuses
> Dave and all, > > Placing the fuse near the power supply end is the way to do it. > In the event of a short, the power wire can spew metal and start a fire. > Always fuse near the power supply.? A fuse at the equipment end will > only protect the equipment, but will expose the wire from the power > supply to hazards. > > 73, > Don W3FPR Also, if at all possible, do not connect directly to the Negative side of the battery without a fuse. In the event of a (not uncommon) fault with the batteries own ground strap, your radio etc will try to conduct a large proportion of the engine cranking current, that doesn't end well. (I have seen CB sets explode under such conditions!) Sketch out the starting circuit, then include your radio's power wiring and you'll see the problem. (Include the antenna ground connection!) With some modern vehicles, such a connection can also affect the battery charging system behaviour, as a bulk current sensor could be bypassed by your wiring resulting in overcharging the battery under some conditions. Some vehicles also use the alternator to provide extra engine breaking, resulting in large charging currents and voltage changes for short periods (seconds) while overall the battery is never "fully" charged, to accommodate such short term usage without damage. For Safety, it is best to connect the radio -ve direct to the vehicle chassis ground, not the battery negative. If you do have to connect directly to the vehicle battery negative (for a temporary install, during an EMCOM event for example) then check the condition of the vehicles battery ground strap first, AND use a Fuse in the radio -ve lead. (If you ever find that fuse has failed for no "apparent" reason, you need to check the health of vehicle battery cabling in detail.) Always check the vehicle handbook for advice about such things too. Having suffered a vehicle electrical fire* while driving, I can tell you, you do not want that experience. (* Unrelated to any amateur radio matters, it was due to a "money saving feature" by the vehicle maker, that over time eventually caused a short to ground of a lighting circuit, that was also not fused!) Take care. Dave G8KBV -- Created on and sent from a Unix like PC running and using free and open source software: __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] In Line Power Pole Fuses
I'm in general agreement with Bob, but there are some details. (1) You don't want to melt you power supply wires. If you trust the power supply device to properly current limit, then you don't need a fuse. If you are using something like my old solar/deep cycle battery supply, you definitely need a fuse. (2) The important thing about voltage drop is getting enough voltage to the final amp in the radio to avoid producing all kinds of distortion in the output signal. This distortion results in a bad signal that causes interference with neighbors on the band. If you are running 14.5 volts receive load, you can afford a bigger voltage drop than if you are running off of batteries at 12 volts receive load. In this latter case, you probably can't afford any voltage drop at all and should throttle back to a maximum of 50 watts or so to clean up your signal. Our real-life experience was one Field Day with our QRP digital K3 station. The deep cycle lead/acid battery was getting tired. The people in the CW tent were complaining of interference from the digital station. A fresh battery fixed the problem. 73 Bill AE6JV On 7/22/21 at 6:27 AM, rmcg...@benlomand.net (Bob McGraw) wrote: With that power supply, which has both good over voltage protection and current limiting, adding fuses in the DC line will add resistance to the line. Even being a small amount, it will affect voltage regulation from no load to rated load at the radio. For this reason I do not recommend adding fuses to the DC power cables. I agree that all 100 watt transceivers should have their DC power leads connected direct to the power supply terminals and not through any DC distribution device. As a rule, receive load to 100 watt CW/key closed transmit load, the voltage drop at the radio should be less than 0.5 volts. Bill Frantz| Art is how we decorate space, 408-348-7900 | music is how we decorate time. www.pwpconsult.com | -Jean-Michel Basquiat __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] In Line Power Pole Fuses
With that power supply, which has both good over voltage protection and current limiting, adding fuses in the DC line will add resistance to the line. Even being a small amount, it will affect voltage regulation from no load to rated load at the radio. For this reason I do not recommend adding fuses to the DC power cables. I agree that all 100 watt transceivers should have their DC power leads connected direct to the power supply terminals and not through any DC distribution device. As a rule, receive load to 100 watt CW/key closed transmit load, the voltage drop at the radio should be less than 0.5 volts. 73 Bob, K4TAX Message: 19 Date: Wed, 21 Jul 2021 19:18:48 -0700 From: Peder Kittelson To:Elecraft@mailman.qth.net Subject: [Elecraft] In Line Power Pole Fuses Message-ID: Content-Type: text/plain; charset="UTF-8" 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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] In Line Power Pole Fuses
Hi Ray, Are you currently using a 25 amp? If so, have you had any issues with that, and are you running P3/SVGA, etc? 25 amps seems quite close to the rated current draw of the K3. I believe the K3 can draw 22 amps on full power, and as Jim said, other items all add up. I also mentioned that the fuse is not there to protect the radio, but to stop other issues, and that I place the fuse as close to the PS as possible to protect the most part of my power wiring. So for me 30 amps, seems OK. If I get a PS short, a 30 amp fuse will blow almost as quickly as a 25 amp fuse, and that is what my main worries are, shorts caused by stupid mistakes on my part, or problems within the equipment connected to the radio. As I mentioned, if the fuse is blowing, and it is a result of radio current overdraw, chances are the radio is already broken. 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 10:31 PM, Ray wrote: 30 Amp --- A little too High for me ! I would use 25 Amp. WA6VAB Ray K3 *From: *Dave <mailto:d...@nk7z.net> *Sent: *Wednesday, July 21, 2021 7:43 PM *To: *elecraft@mailman.qth.net <mailto:elecraft@mailman.qth.net> *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:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to d...@nk7z.net > __ Elecraft mailing list Home: http://mailman.qth.ne
Re: [Elecraft] In Line Power Pole Fuses
On 7/21/2021 10:49 PM, Rick NK7I wrote: 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. A study of fuse (and breaker) specs is worthwhile. In general, fuses are rated by average current, with considerable allowance for spikes and surges above that. A standard fuse (not a Slo-Blo) will not blow on spikes 25% higher than it's nominal rating, and fuses have time responses. We want fuses and breakers to pop when something breaks, not when there's an unusual spike that doesn't persist. My most personal experience with fuses blowing on my gear has been with TenTec Titans that I ran for years. Generally quite reliable, but mains fuses would blow on crap on the AC line, not on equipment failure, which is what they are intended to prevent. Both sides of the line are fused, and if equal ratings, both will blow. I soon realized that a 20A fuse on one side and 30A on the other was a very good idea. 73, Jim K9YC __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] In Line Power Pole Fuses
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 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: elecraft@mailman.qth.net > 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:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to d...@nk7z.net >> > __ > 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 > Message delivered to wa6...@gmail.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
Re: [Elecraft] In Line Power Pole Fuses
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: elecraft@mailman.qth.net 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:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to d...@nk7z.net > __ 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 Message delivered to wa6...@gmail.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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] In Line Power Pole Fuses
Same for auto installs... I see far too many fuses at the radio end of things... Short in the power wiring, turns into your auto burning itself down, as that long run of power cable burns up. 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 8:35 PM, Don Wilhelm wrote: Dave and all, Placing the fuse near the power supply end is the way to do it. In the event of a short, the power wire can spew metal and start a fire. Always fuse near the power supply. A fuse at the equipment end will only protect the equipment, but will expose the wire from the power supply to hazards. 73, Don W3FPR On 7/21/2021 10:43 PM, Dave wrote: 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. __ 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 Message delivered to d...@nk7z.net __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] In Line Power Pole Fuses
Dave and all, Placing the fuse near the power supply end is the way to do it. In the event of a short, the power wire can spew metal and start a fire. Always fuse near the power supply. A fuse at the equipment end will only protect the equipment, but will expose the wire from the power supply to hazards. 73, Don W3FPR On 7/21/2021 10:43 PM, Dave wrote: 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. __ 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 Message delivered to arch...@mail-archive.com
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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to d...@nk7z.net __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] In Line Power Pole Fuses
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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
