Re: [Elecraft] K3 going expeditionary
As is often the case, connecting directly to the battery for the negative lead is misunderstood. In today's world, it depends. The Battery Monitoring System (BMS) is a big deal in most of today's vehicles. To function properly, we should NOT CONNECT to the battery's negative terminal. That used to be good advice and may be bad today. See: http://www.k0bg.com/wiring.html. As Alan, K0BG, states, "It WORKs." often means "WithOut Real Knowledge. Not all advice on this reflector is current or correct. Caveat emptor. BTW, using vehicle wiring for a 100 Watt radio can lead to losing the vehicle due to fire! I have seen the pictures. I worked in the Gulf of Mexico oil fields. I swatted down with gusto the idea of "It's only temporary." and "I can do it quickly." Do it right, even if it's for an hour or a weekend. 73, Bill, K8TE -- 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3 going expeditionary
On 8/24/2020 8:17 PM, Clay Autery wrote: Side bonus, was that the 12VDC ground plane was so good afterwards, that I have been able to take out a lot of the home run grounds from a bunch of lights, et al... ofsetting weight gain by some bit. Important fundamental concept, Clay, that I learned in an IEEE EMC workshop. DC follows the path of least RESISTANCE. AC follows the path of least IMPEDANCE. If there is a transmission line with, for example, a chassis in parallel with the transmission line return, above about 1 kHz, all the return current will be in the transmission line, NOT in the lower resistance chassis. That's because the return patch through the chassis includes a lot of INDUCTIVE REACTANCE, which increases in proportion to frequency, while the path through the transmission line, if matched, never rises about Zo of the line. The whole point of using the transmission line is to reduce noise and crosstalk. It's only effect on DC (as compared to the chassis path) is to slightly reduce the DCR of the return path by adding the transmission line return in parallel. With coax, of course, the shield is the return. Wtih 2-wire line, one conductor is the "hot" lead, the other the return. AND -- 2-wire line and coax are no different in this regard! The KPA500, for example, uses twisted pair for wiring from the input coax to the amp input stage. 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] K3 going expeditionary
Yup When I did my alternator and battery upgrade (including a complete replacement of the power/ground cables with much heavier cable), for my stereo install, I discovered that very thing even in a TRUCK with a frame. I mapped out and installed massive ground continuity cables from every metal body part to the frame, and finished up by MEASURING the resistance from point to point all over the body, bed, cab, frame, and engine to insure that the entire ground plane was continuous and super low resistance. Maybe overkill, but it works great, and it gives me comfort to know that vibration dampening and oxidation aren't compromising the counterpoise. Side bonus, was that the 12VDC ground plane was so good afterwards, that I have been able to take out a lot of the home run grounds from a bunch of lights, et al... ofsetting weight gain by some bit. 73, __ Clay Autery, KY5G (318) 518-1389 On 08/24/20 17:40, Jim Brown wrote: Yes, and this should definitely be twisted pair, contrary to what's on a highly regarded mobile site. Also, radio equipment in vehicles should NOT by bonded to the frame/chassis/vehicle metal. OTOH, coax return for HF mobile antennas SHOULD be bonded to vehicle metal, because that's what serves as its counterpoise (often called a ground plane). BTW -- a major obstacle to this being a good ground plane is that the metal parts of many (most?) vehicles are insulated from each other by paint. An ohmmeter study between parts of the chassis is a worthwhile effort. 73, Jim K9YC On 8/24/2020 3:01 PM, Steve Hall wrote: I highly recommend you run a power lead to the battery (ideally) or the main power bus in the car interior rather than tap off the limited accessory socket. Keep well under the fuse rating that feeds the accessory plug if you go that route. Steve WM6P __ 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 j...@audiosystemsgroup.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 k...@montac.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] K3 going expeditionary
"Had to disconnect main battery terminals to reboot the computer to get home." 440 in my old Ford Ranger just cancelled the cruise control if it was engaged. Just like Windoze Jim! Glad your house has survived ... really hoping for Bob's. 73, Fred ["Skip"] K6DGW Sparks NV DM09dn Washoe County On 8/24/2020 3:45 PM, Jim Brown wrote: On 8/24/2020 9:03 AM, Mike Short wrote: RFI on audio, agreed. Noise on DC, not so much. Routing is the most important factor for DC power. It is hard to get enough turns on the proper size wire to make a difference. Yes, routing is important. But what you're missing is that a major issue is RF getting into the vehicle's computers, and the RF noise from those computers getting into our DC wiring. I learned this the hard way with my 2006 big Toyota SUV. Calling CQ barefoot on 20M SSB put the car's computer into "limp-home" mode in the NV high desert. Had to disconnect main battery terminals to reboot the computer to get home. 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] K3 going expeditionary
On 8/24/2020 9:03 AM, Mike Short wrote: RFI on audio, agreed. Noise on DC, not so much. Routing is the most important factor for DC power. It is hard to get enough turns on the proper size wire to make a difference. Yes, routing is important. But what you're missing is that a major issue is RF getting into the vehicle's computers, and the RF noise from those computers getting into our DC wiring. I learned this the hard way with my 2006 big Toyota SUV. Calling CQ barefoot on 20M SSB put the car's computer into "limp-home" mode in the NV high desert. Had to disconnect main battery terminals to reboot the computer to get home. 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] K3 going expeditionary
Yes, and this should definitely be twisted pair, contrary to what's on a highly regarded mobile site. Also, radio equipment in vehicles should NOT by bonded to the frame/chassis/vehicle metal. OTOH, coax return for HF mobile antennas SHOULD be bonded to vehicle metal, because that's what serves as its counterpoise (often called a ground plane). BTW -- a major obstacle to this being a good ground plane is that the metal parts of many (most?) vehicles are insulated from each other by paint. An ohmmeter study between parts of the chassis is a worthwhile effort. 73, Jim K9YC On 8/24/2020 3:01 PM, Steve Hall wrote: I highly recommend you run a power lead to the battery (ideally) or the main power bus in the car interior rather than tap off the limited accessory socket. Keep well under the fuse rating that feeds the accessory plug if you go that route. Steve WM6P __ 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 j...@audiosystemsgroup.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
[Elecraft] K3 going expeditionary
I highly recommend you run a power lead to the battery (ideally) or the main power bus in the car interior rather than tap off the limited accessory socket. Keep well under the fuse rating that feeds the accessory plug if you go that route. Steve WM6P __ 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] K3 going expeditionary
On 8/24/2020 11:56 AM, Ted Edwards W3TB wrote: My thanks to everybody. It is rather overwhelming for just a Sunday afternoon of portable operation in remote counties powered by the car. I will really want to keep simple in those terms. In that contest, I'd simply use smaller gauge twisted pair. 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] K3 going expeditionary
My thanks to everybody. It is rather overwhelming for just a Sunday afternoon of portable operation in remote counties powered by the car. I will really want to keep simple in those terms. Reading through all this several times. Thanks to all who contributed. On Mon, Aug 24, 2020 at 11:26 AM Jim Brown wrote: > Of course it applies. Mother nature does not pay attention to what we > CALL things. It is quite common for DC and mains power to carry AF and > RF currents. That's how most noise is radiated -- as a common mode > signal on cables connected to equipment that includes noise sources. > > BTW -- as Vice-Chair of AES Standards Committee for 20 years, I HAVE > studied this stuff extensively, along with colleagues around the world > with excellent engineering chops. > > 73, Jim K9YC > > On 8/24/2020 8:47 AM, Rich NE1EE wrote: > > Well...this reply covers a lot of ground. We are addressing power lines > running DC, not signal lines with high freq signals? Even audio moves the > question from DC to audio frequencies. I have seen coupling of AC to very > long DC signal wires (current loop or voltage sensors, such as RTD), but I > am addressing hundreds of meters. I have not looked at the effect for > shorter wires running essentially DC, in an environment where there are > high freq signals to couple. But then, I included the inline filter from > the start, so I don't know if it did any good or not. For $30 (I think?), > it was not worth thinking about. I'm familiar with twisting, crosstalk, > etc, for signals, but not sure that it translates to DC power supplies of > short length. > > __ > 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 w3tb@gmail.com > -- 73 de Ted Edwards, W3TB and GØPWW and thinking about operating CW: "Do today what others won't, so you can do tomorrow what others can't." __ 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] K3 going expeditionary
Of course it applies. Mother nature does not pay attention to what we CALL things. It is quite common for DC and mains power to carry AF and RF currents. That's how most noise is radiated -- as a common mode signal on cables connected to equipment that includes noise sources. BTW -- as Vice-Chair of AES Standards Committee for 20 years, I HAVE studied this stuff extensively, along with colleagues around the world with excellent engineering chops. 73, Jim K9YC On 8/24/2020 8:47 AM, Rich NE1EE wrote: Well...this reply covers a lot of ground. We are addressing power lines running DC, not signal lines with high freq signals? Even audio moves the question from DC to audio frequencies. I have seen coupling of AC to very long DC signal wires (current loop or voltage sensors, such as RTD), but I am addressing hundreds of meters. I have not looked at the effect for shorter wires running essentially DC, in an environment where there are high freq signals to couple. But then, I included the inline filter from the start, so I don't know if it did any good or not. For $30 (I think?), it was not worth thinking about. I'm familiar with twisting, crosstalk, etc, for signals, but not sure that it translates to DC power supplies of short length. __ 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] K3 going expeditionary
RFI on audio, agreed. Noise on DC, not so much. Routing is the most important factor for DC power. It is hard to get enough turns on the proper size wire to make a difference. On Mon, Aug 24, 2020 at 10:24 AM Jim Brown wrote: > On 8/24/2020 8:11 AM, Mike Short wrote: > > Twisting the wires doesn’t do anything. > > Au contraire! Twisting provides an excellent rejection of of crosstalk, > including RFI. Have you not noticed that CAT5/6/7 cables are four > tightly twisted pairs, each with a slightly different twist ratio, all > very well engineered to minimize crosstalk between them? Twisted pair > has been widely used in pro audio for a century. Beginning with the > earliest days of telephony, their cables were run on the same poles as > AC, with a crossover every other pole to provide the twist (the only > rejection needed was at 60 Hz, 50 Hz in EU). > > Those who make and sell zip cord, glorified or otherwise, as speaker > cable are ignorant of this. When I lived in Chicago, I solved a lot of > RFI to home stereo systems by replacing such with twisted pair. > > 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 ai4ns.m...@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] K3 going expeditionary
On 8/24/2020 8:11 AM, Mike Short wrote: Twisting the wires doesn’t do anything. Au contraire! Twisting provides an excellent rejection of of crosstalk, including RFI. Have you not noticed that CAT5/6/7 cables are four tightly twisted pairs, each with a slightly different twist ratio, all very well engineered to minimize crosstalk between them? Twisted pair has been widely used in pro audio for a century. Beginning with the earliest days of telephony, their cables were run on the same poles as AC, with a crossover every other pole to provide the twist (the only rejection needed was at 60 Hz, 50 Hz in EU). Those who make and sell zip cord, glorified or otherwise, as speaker cable are ignorant of this. When I lived in Chicago, I solved a lot of RFI to home stereo systems by replacing such with twisted pair. 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] K3 going expeditionary
Twisting the wires doesn’t do anything. On Mon, Aug 24, 2020 at 09:28 Clay Autery wrote: > IF it were me, I would run two NEW, 10GA or better high strand count > > wires (twisted by hand or drill) from the battery to the cabin with > > appropriate fuses in BOTH POS and NEG lines, and the Anderson PP > > connector on the end. > > Ideally, I would also put a SPST switch in the POS (my pref), or a DPST > > switch across both leads so that I could turn the power off there for > > connection purposes (optional). > > > > This gives you the ability to 1) power the K3 with Key off, engine off > > if desired, and 2) gives you a big, shortest run dedicated to the radio. > > Additionally, it gives you a twisted pair, AND the ability to put chokes > > wherever you might need them to quiet down the power source from > > possible noise from the vehicle. > > > > 73, > > > > __ > > Clay Autery, KY5G > > (318) 518-1389 > > > > On 08/23/20 13:32, Ed K1EP wrote: > > > You could do that. I wouldn't advise it for other reasons. Why don't you > > > measure the current at different power levels when on a power supply? > There > > > is a current display on the radio. The cigarette plug is not directly > > > connected to the battery. There is likely to be poor connections > resulting > > > in IR losses and other problems. > > > > > > On Sun, Aug 23, 2020, 14:22 Ted Edwards W3TB wrote: > > > > > >> I am planning to put my K3 in the car for the upcoming Tennessee QSO > Party > > >> so that I can go rover/expeditionary. > > >> > > >> With that comes a question: Powering from that accessory socket which > > >> appears limited to 15 amps instead of the 20 amps that the K3 wants at > full > > >> power, do I understand right that reducing to 50 watts output and taking > > >> the -3dB will work out in terms of power draw? > > >> > > >> In the past, I have done QRP and would like to be a bit louder this > time. > > >> Thanks to all who might respond. > > >> > > >> -- > > >> 73 de Ted Edwards, W3TB and GØPWW > > >> > > >> and thinking about operating CW: > > >> "Do today what others won't, > > >> so you can do tomorrow what others can't." > > >> __ > > >> 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 k1ep.l...@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 k...@montac.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 ai4ns.m...@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] K3 going expeditionary
IF it were me, I would run two NEW, 10GA or better high strand count wires (twisted by hand or drill) from the battery to the cabin with appropriate fuses in BOTH POS and NEG lines, and the Anderson PP connector on the end. Ideally, I would also put a SPST switch in the POS (my pref), or a DPST switch across both leads so that I could turn the power off there for connection purposes (optional). This gives you the ability to 1) power the K3 with Key off, engine off if desired, and 2) gives you a big, shortest run dedicated to the radio. Additionally, it gives you a twisted pair, AND the ability to put chokes wherever you might need them to quiet down the power source from possible noise from the vehicle. 73, __ Clay Autery, KY5G (318) 518-1389 On 08/23/20 13:32, Ed K1EP wrote: You could do that. I wouldn't advise it for other reasons. Why don't you measure the current at different power levels when on a power supply? There is a current display on the radio. The cigarette plug is not directly connected to the battery. There is likely to be poor connections resulting in IR losses and other problems. On Sun, Aug 23, 2020, 14:22 Ted Edwards W3TB wrote: I am planning to put my K3 in the car for the upcoming Tennessee QSO Party so that I can go rover/expeditionary. With that comes a question: Powering from that accessory socket which appears limited to 15 amps instead of the 20 amps that the K3 wants at full power, do I understand right that reducing to 50 watts output and taking the -3dB will work out in terms of power draw? In the past, I have done QRP and would like to be a bit louder this time. Thanks to all who might respond. -- 73 de Ted Edwards, W3TB and GØPWW and thinking about operating CW: "Do today what others won't, so you can do tomorrow what others can't." __ 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 k1ep.l...@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 k...@montac.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] K3 going expeditionary
Go to K0BG.com and read everything. His site is probably the best resource on the internet for mobile operations. Mike On Sun, Aug 23, 2020 at 3:17 PM Rick NK7I wrote: > Not only is the accessory circuit shared with others, it is often loaded > with noises from the electronics in the vehicle. They can harm both > your RX and TX signals. > > It takes a little time to run #12 ROMEX (with 40 or 50 A mobile, > self-resetting circuit breakers at the battery to protect the wire, > fuses for radios AT the radios; both positive and negative) but the > returns are worth it. You'll have to remember to turn the K3 OFF each > time you start the engine; the wandering voltage could cause harm or > scramble the settings. Also bond to chassis AT the K3 to keep some RFI > down... > > *IF* you have a newer vehicle that measures current draw and charging > rate at the battery (sometimes via the negative pole), you'll want to > use that sensor point for negative connection; not at the battery. > > That's the super quick description, to start a foundation of proper set up. > > 73, > Rick NK7I > > > > > >> I am planning to put my K3 in the car for the upcoming Tennessee QSO > Party > >> so that I can go rover/expeditionary. > >> > >> With that comes a question: Powering from that accessory socket which > >> appears limited to 15 amps instead of the 20 amps that the K3 wants at > full > >> power, do I understand right that reducing to 50 watts output and taking > >> the -3dB will work out in terms of power draw? > >> > >> In the past, I have done QRP and would like to be a bit louder this > time. > >> Thanks to all who might respond. > >> > >> -- > >> 73 de Ted Edwards, W3TB and GØPWW > > __ 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] K3 going expeditionary
Not only is the accessory circuit shared with others, it is often loaded with noises from the electronics in the vehicle. They can harm both your RX and TX signals. It takes a little time to run #12 ROMEX (with 40 or 50 A mobile, self-resetting circuit breakers at the battery to protect the wire, fuses for radios AT the radios; both positive and negative) but the returns are worth it. You'll have to remember to turn the K3 OFF each time you start the engine; the wandering voltage could cause harm or scramble the settings. Also bond to chassis AT the K3 to keep some RFI down... *IF* you have a newer vehicle that measures current draw and charging rate at the battery (sometimes via the negative pole), you'll want to use that sensor point for negative connection; not at the battery. That's the super quick description, to start a foundation of proper set up. 73, Rick NK7I On 8/23/2020 11:32 AM, Ed K1EP wrote: You could do that. I wouldn't advise it for other reasons. Why don't you measure the current at different power levels when on a power supply? There is a current display on the radio. The cigarette plug is not directly connected to the battery. There is likely to be poor connections resulting in IR losses and other problems. On Sun, Aug 23, 2020, 14:22 Ted Edwards W3TB wrote: I am planning to put my K3 in the car for the upcoming Tennessee QSO Party so that I can go rover/expeditionary. With that comes a question: Powering from that accessory socket which appears limited to 15 amps instead of the 20 amps that the K3 wants at full power, do I understand right that reducing to 50 watts output and taking the -3dB will work out in terms of power draw? In the past, I have done QRP and would like to be a bit louder this time. Thanks to all who might respond. -- 73 de Ted Edwards, W3TB and GØPWW and thinking about operating CW: "Do today what others won't, so you can do tomorrow what others can't." __ 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 k1ep.l...@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 rick.n...@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] K3 going expeditionary
Concur. The K3 can in my experience be vulnerable to voltage drop which can happen with a questionable power source. For a rig like the K3 you should draw straight from the battery. You can add some additional protection in a mobile setup by incorporating a voltage regulator In the circuit just before the K3. -Original Message- From: elecraft-boun...@mailman.qth.net On Behalf Of Ed K1EP Sent: Sunday, August 23, 2020 11:32 AM To: Ted Edwards W3TB Cc: Elecraft Reflector Subject: Re: [Elecraft] K3 going expeditionary You could do that. I wouldn't advise it for other reasons. Why don't you measure the current at different power levels when on a power supply? There is a current display on the radio. The cigarette plug is not directly connected to the battery. There is likely to be poor connections resulting in IR losses and other problems. On Sun, Aug 23, 2020, 14:22 Ted Edwards W3TB wrote: > I am planning to put my K3 in the car for the upcoming Tennessee QSO > Party so that I can go rover/expeditionary. > > With that comes a question: Powering from that accessory socket which > appears limited to 15 amps instead of the 20 amps that the K3 wants at > full power, do I understand right that reducing to 50 watts output and > taking the -3dB will work out in terms of power draw? > > In the past, I have done QRP and would like to be a bit louder this time. > Thanks to all who might respond. > > -- > 73 de Ted Edwards, W3TB and GØPWW > > and thinking about operating CW: > "Do today what others won't, > so you can do tomorrow what others can't." > __ > 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 > k1ep.l...@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 gthorn...@thorntonmostullaw.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] K3 going expeditionary
You could do that. I wouldn't advise it for other reasons. Why don't you measure the current at different power levels when on a power supply? There is a current display on the radio. The cigarette plug is not directly connected to the battery. There is likely to be poor connections resulting in IR losses and other problems. On Sun, Aug 23, 2020, 14:22 Ted Edwards W3TB wrote: > I am planning to put my K3 in the car for the upcoming Tennessee QSO Party > so that I can go rover/expeditionary. > > With that comes a question: Powering from that accessory socket which > appears limited to 15 amps instead of the 20 amps that the K3 wants at full > power, do I understand right that reducing to 50 watts output and taking > the -3dB will work out in terms of power draw? > > In the past, I have done QRP and would like to be a bit louder this time. > Thanks to all who might respond. > > -- > 73 de Ted Edwards, W3TB and GØPWW > > and thinking about operating CW: > "Do today what others won't, > so you can do tomorrow what others can't." > __ > 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 k1ep.l...@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
[Elecraft] K3 going expeditionary
I am planning to put my K3 in the car for the upcoming Tennessee QSO Party so that I can go rover/expeditionary. With that comes a question: Powering from that accessory socket which appears limited to 15 amps instead of the 20 amps that the K3 wants at full power, do I understand right that reducing to 50 watts output and taking the -3dB will work out in terms of power draw? In the past, I have done QRP and would like to be a bit louder this time. Thanks to all who might respond. -- 73 de Ted Edwards, W3TB and GØPWW and thinking about operating CW: "Do today what others won't, so you can do tomorrow what others can't." __ 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
