K3 13.8 VDC power
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Is anyone floating a battery across their power distribution?
Dick, n0ce ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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On Sun,12/21/2014 11:31 PM, Richard Fjeld wrote:
> Is anyone floating a battery across their power distribution? Sure. I've done it for ten years. A fundamental requirement is a regulated supply set to a voltage that is matched to the battery's desired charging or float voltage. You want to keep the battery charged while not overcharging it. I run a contesting station with two K3s driving power amps with a 10A supply keeping the battery charged during the winter, and solar panels doing it during the summer. 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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On Sun,12/21/2014 11:44 PM, Jim Brown wrote:
> I run a contesting station with two K3s driving power amps with a 10A > supply keeping the battery charged during the winter, and solar panels > doing it during the summer. Clarification: For the 2-radio contesting system, I use two 6V 210AH Golf Cart Batteries in series. For a single radio setup, I used a single 12V battery of the biggest that Costco sells, about 80 AH. Solar is useless for me during the winter because I'm surrounded by VERY tall redwoods, whose shadows limit my sunlight at panels to a few hours per day during the winter and 6 hours during the summer. Those with more hospitable light exposure may be able to make greater use or szolar power. :) I run all the 12V gear from this system -- K3, P3, preamps for Beverages, switching for antennas, etc. 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by Richard Fjeld
> On Dec 22, 2014, at 2:31 AM, Richard Fjeld <[hidden email]> wrote:
> > Is anyone floating a battery across their power distribution? > > Dick, n0ce In almost every case possible. Uninterrupted communications is a very important concept IMHO. A trick (or maybe not) that I have recently used to address the charging issue, is to use a ‘Solar Charge Controller’, of the appropriate amperage rating, of course. These devices have a solar input (suitable for a Linear type power supply. Not quite sure how it would behave connected to a switcher), a Battery Interconnect, and Load out. Many devices include charging control circuits that you can match to your batteries fairly well, and a Low Voltage Disconnect (LVD) to keep your batteries from over discharging. I have this setup on my K3 and it works great. I have the K3’s Low Voltage warning set to .3v above LVD cut-out (on the charge controller). This lets me know when the batteries are close to the bottom. This is a great feature that helps you with not destroying your batteries. Walter K3WCA ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by Richard Fjeld
There are some cautions in floating a battery with a mains power
supply. For example, the ProAudio Engineering PAE-Kx33 4A switching power supply I am using with my KX3 specifically says not to use the power supply for directly charging batteries, and voids the warranty if you do. I had a prototype battery charge controller I was designing let the magic smoke out when the input power dropped and the battery sent current backwards through the circuit. The tantalum cap was actually in flame. (A diode was part of the fix.) Like Jim, I use a solar charge controller <http://www.cirkits.com/scc3/> to charge the batteries which run my K3 station. 73 Bill AE6JV On 12/22/14 at 11:31 PM, [hidden email] (Richard Fjeld) wrote: >Is anyone floating a battery across their power distribution? > >Dick, n0ce --------------------------------------------------------------------------- Bill Frantz | "I wish there was a knob on the TV to turn up the 408-356-8506 | intelligence. There's a knob called "brightness", but www.pwpconsult.com | it doesn't work. -- Gallagher ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by Jim Brown-10
Jim Brown <[hidden email]> writes:
> I run a contesting station with two K3s driving power amps with a 10A > supply keeping the battery charged during the winter, and solar panels > doing it during the summer. What do you do about the voltage being 12.5ish instead of 13.8? Run the K3s at reduced power (because of the amps you are doing anyway)? Don't worry about extra IMD? Use a DC-DC converter to get 13.8V? ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by Bill Frantz
The SCC3 is in use here too. The basic 20 Amp unit can be scaled up
to higher rated amperage by adding additional FETs. The instructions for this are included. 73, matt W6NIA On Mon, 22 Dec 2014 06:49:49 -0800, you wrote: >There are some cautions in floating a battery with a mains power >supply. For example, the ProAudio Engineering PAE-Kx33 4A >switching power supply I am using with my KX3 specifically says >not to use the power supply for directly charging batteries, and >voids the warranty if you do. > >I had a prototype battery charge controller I was designing let >the magic smoke out when the input power dropped and the battery >sent current backwards through the circuit. The tantalum cap was >actually in flame. (A diode was part of the fix.) > >Like Jim, I use a solar charge controller ><http://www.cirkits.com/scc3/> to charge the batteries which run >my K3 station. > >73 Bill AE6JV > >On 12/22/14 at 11:31 PM, [hidden email] (Richard Fjeld) wrote: > >>Is anyone floating a battery across their power distribution? >> >>Dick, n0ce > >--------------------------------------------------------------------------- >Bill Frantz | "I wish there was a knob on the TV to turn >up the >408-356-8506 | intelligence. There's a knob called >"brightness", but >www.pwpconsult.com | it doesn't work. -- Gallagher > >______________________________________________________________ >Elecraft mailing list >Home: http://mailman.qth.net/mailman/listinfo/elecraft >Help: http://mailman.qth.net/mmfaq.htm >Post: mailto:[hidden email] > >This list hosted by: http://www.qsl.net >Please help support this email list: http://www.qsl.net/donate.html >Message delivered to [hidden email] -- "Give me six hours to chop down a tree and I will spend the first four sharpening the axe." -A. Lincoln ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by Greg Troxel-2
On Mon,12/22/2014 7:05 AM, Greg Troxel wrote:
> Jim Brown <[hidden email]> writes: > >> I run a contesting station with two K3s driving power amps with a 10A >> supply keeping the battery charged during the winter, and solar panels >> doing it during the summer. > What do you do about the voltage being 12.5ish instead of 13.8? Run the > K3s at reduced power (because of the amps you are doing anyway)? Don't > worry about extra IMD? Use a DC-DC converter to get 13.8V? Most of my contesting is done either at legal limit, with the K3s driving an amp or at QRP. For NAQP, of course, i run 100W. Even at 100W and 12.5V the K3 is pretty clean, and at the 40-50W level it takes to drive my Ten Tec Titans, even cleaner. The measurements in the link below were taken with my usual power setup. k9yc.com/P3_SpectrumMeasurements.pdf Someone mentioned using a solar charge controller. I'm using a GV MPPT charge controller between my solar panels and the battery. It's RF quiet. Most charge controllers make RF noise. GV makes several models for different battery types, voltages, and current ratings. They are available here. The company also seems to be a good place to buy Li batteries. http://www.batteryspace.com/140w-10a-solar-charge-controller-with-mppt-for-lithium-batteries.aspx 73, Jim K9YC 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by Richard Fjeld
Wow, thanks to all for the greatly informative answers. I gleaned many
good ideas from them. This is my concern; I am interested in protecting my K3 from damage by not being shut down properly should a power interruption occur while the K3 is operating. For this design, I'm thinking about a worst case scenario; in transmit mode at 100 watts/20 amps, plus accessories on. I am concerned about Hydrogen gas while charging a lead-acid battery here in the furnace room. Since I don't need to operate by battery power, I'd like to know your thoughts about if a Gel-Cel battery of a 9 amp variety would handle the 20 amp load until I could go to receive mode and properly shut down? I haven't had any experience drawing that much amperage from a gel-cel momentarily. I don't know if the load voltage would be adequate to keep the K3 alive. I'd need to test it using an older style radio. I'm hoping someone has had experience related to this. Thanks in advance for comments, Dick, n0ce On 12/22/2014 1:31 AM, Richard Fjeld wrote: > Is anyone floating a battery across their power distribution? > > Dick, n0ce > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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Dick,
Yes, hydrogen outgassing is a potential problem, and the area containing a normal lead-acid battery should not only be protected from sparks and ignition sources, but should also be vented to the outside. I would suggest that you look at a larger gel cell or an AGM battery. If you use a normal lead acid deep cycle battery, you could enclose it in a tight battery box (often used in RVs) which has a vent hose that you could route outside. 73, Don W3FPR On 12/22/2014 2:51 PM, Richard Fjeld wrote: > Wow, thanks to all for the greatly informative answers. I gleaned > many good ideas from them. > > This is my concern; I am interested in protecting my K3 from damage by > not being shut down properly should a power interruption occur while > the K3 is operating. For this design, I'm thinking about a worst case > scenario; in transmit mode at 100 watts/20 amps, plus accessories on. > > I am concerned about Hydrogen gas while charging a lead-acid battery > here in the furnace room. Since I don't need to operate by battery > power, I'd like to know your thoughts about if a Gel-Cel battery of a > 9 amp variety would handle the 20 amp load until I could go to receive > mode and properly shut down? > I haven't had any experience drawing that much amperage from a gel-cel > momentarily. I don't know if the load voltage would be adequate to > keep the K3 alive. I'd need to test it using an older style radio. > I'm hoping someone has had experience related to this. > > Thanks in advance for comments, > > Dick, n0ce > > > On 12/22/2014 1:31 AM, Richard Fjeld wrote: >> Is anyone floating a battery across their power distribution? >> >> Dick, n0ce >> >> > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by Richard Fjeld
On Mon,12/22/2014 11:51 AM, Richard Fjeld wrote:
> This is my concern; I am interested in protecting my K3 from damage by > not being shut down properly should a power interruption occur while > the K3 is operating. For this design, I'm thinking about a worst case > scenario; in transmit mode at 100 watts/20 amps, plus accessories on. You are overly concerned, but having battery backup is a good thing. Concerns about outgassing notwithstanding, I've never used anything more than the voltage regulator on the power supply to limit the charge, and I've always used ordinary deep cycle batteries. The key is to limit that voltage to what the battery expects, and to limit the charging current to what the battery will take as a "trickle" once it's reached full charge. Those are not difficult to do if you simply monitor battery voltage and charge current. 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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Another problem is that outgasing gases are corrosive and can damage
electronics especially contacts, relays, connectors, pots and the like. Nick N1KMP ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by Richard Fjeld
Dick:
Unless you are looking for something to do, I also suggest you are over concerned. During the recent CQWW CW on the island of St. Croix, we had 3 K3s all driving amps. We probably had 3 or 4 outages without incident. Similarly, as a single op on the island of Montserrat during the last ARRL SSB, I had a K3 barefoot. Again, something like 3 or 4 power outages during the contest. No problems. Once that 12 volts into the K3 reaches its lower limit, the radio's off. "Shutting down properly during a power interruption" might be a different, and more difficult requirement, than just batter backup. 73 charlie, k1xx On 12/22/2014 2:51 PM, Richard Fjeld wrote: > Wow, thanks to all for the greatly informative answers. I gleaned > many good ideas from them. > > This is my concern; I am interested in protecting my K3 from damage by > not being shut down properly should a power interruption occur while > the K3 is operating. For this design, I'm thinking about a worst case > scenario; in transmit mode at 100 watts/20 amps, plus accessories on. > > I am concerned about Hydrogen gas while charging a lead-acid battery > here in the furnace room. Since I don't need to operate by battery > power, I'd like to know your thoughts about if a Gel-Cel battery of a > 9 amp variety would handle the 20 amp load until I could go to receive > mode and properly shut down? > I haven't had any experience drawing that much amperage from a gel-cel > momentarily. I don't know if the load voltage would be adequate to > keep the K3 alive. I'd need to test it using an older style radio. > I'm hoping someone has had experience related to this. > > Thanks in advance for comments, > > Dick, n0ce > > > On 12/22/2014 1:31 AM, Richard Fjeld wrote: >> Is anyone floating a battery across their power distribution? >> >> Dick, n0ce >> >> > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by Richard Fjeld
I use one of these power supplies with a battery backup module installed (Model: SEC-1223BBM). I have a deep cycle battery attached to it.http://www.samlexamerica.com/products/ProductDetail.aspx?pid=516The hot-switches to battery is very nice when power fails. Also if you happen to draw more than 25A it uses the battery for the difference from up to 35A. It charges the battery at 5A with normal power.Tom - wa4ta
> Date: Mon, 22 Dec 2014 13:51:52 -0600 > From: [hidden email] > To: [hidden email] > Subject: Re: [Elecraft] K3 13.8 VDC power > > Wow, thanks to all for the greatly informative answers. I gleaned many > good ideas from them. > > This is my concern; I am interested in protecting my K3 from damage by > not being shut down properly should a power interruption occur while the > K3 is operating. For this design, I'm thinking about a worst case > scenario; in transmit mode at 100 watts/20 amps, plus accessories on. > > I am concerned about Hydrogen gas while charging a lead-acid battery > here in the furnace room. Since I don't need to operate by battery > power, I'd like to know your thoughts about if a Gel-Cel battery of a 9 > amp variety would handle the 20 amp load until I could go to receive > mode and properly shut down? > I haven't had any experience drawing that much amperage from a gel-cel > momentarily. I don't know if the load voltage would be adequate to keep > the K3 alive. I'd need to test it using an older style radio. I'm > hoping someone has had experience related to this. > > Thanks in advance for comments, > > Dick, n0ce > > > On 12/22/2014 1:31 AM, Richard Fjeld wrote: > > Is anyone floating a battery across their power distribution? > > > > Dick, n0ce > > > > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by Don Wilhelm-4
Dick:
A few more notes. Outgassing is not a normal occurrence of lead acid batteries. It occurs when there is substantial overcharge. That is why you always use a regulator so outgassing doesn't occur. Second SLA stands for sealed lead acid. These batteries are partially sealed to prevent outgassing. They do have blowout plugs to prevent explosions. Finally there are battery monitors available at reasonable cost. They will sound an alarm if your battery voltage is too high or too low thereby giving warning that something is not right. I also attach a 12vdc LED light strip to my power alarm. That way when the house lights go out I can still see the controls to shut things down if need be. 73, Fred, AE6QL -----Original Message----- From: Elecraft [mailto:[hidden email]] On Behalf Of Don Wilhelm Sent: Monday, December 22, 2014 12:06 PM To: Richard Fjeld; [hidden email] Subject: Re: [Elecraft] K3 13.8 VDC power Dick, Yes, hydrogen outgassing is a potential problem, and the area containing a normal lead-acid battery should not only be protected from sparks and ignition sources, but should also be vented to the outside. I would suggest that you look at a larger gel cell or an AGM battery. If you use a normal lead acid deep cycle battery, you could enclose it in a tight battery box (often used in RVs) which has a vent hose that you could route outside. 73, Don W3FPR On 12/22/2014 2:51 PM, Richard Fjeld wrote: > Wow, thanks to all for the greatly informative answers. I gleaned > many good ideas from them. > > This is my concern; I am interested in protecting my K3 from damage by > not being shut down properly should a power interruption occur while > the K3 is operating. For this design, I'm thinking about a worst case > scenario; in transmit mode at 100 watts/20 amps, plus accessories on. > > I am concerned about Hydrogen gas while charging a lead-acid battery > here in the furnace room. Since I don't need to operate by battery > power, I'd like to know your thoughts about if a Gel-Cel battery of a > 9 amp variety would handle the 20 amp load until I could go to receive > mode and properly shut down? > I haven't had any experience drawing that much amperage from a gel-cel > momentarily. I don't know if the load voltage would be adequate to > keep the K3 alive. I'd need to test it using an older style radio. > I'm hoping someone has had experience related to this. > > Thanks in advance for comments, > > Dick, n0ce > > > On 12/22/2014 1:31 AM, Richard Fjeld wrote: >> Is anyone floating a battery across their power distribution? >> >> Dick, n0ce >> >> > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net Please help support this email > list: http://www.qsl.net/donate.html Message delivered to > [hidden email] > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2015.0.5577 / Virus Database: 4257/8787 - Release Date: 12/22/14 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by Jim Brown-10
I'm just curios is there any real test data available showing what IMD
may be present at various supply voltages? I have heard many comments on the reflector over the years saying to keep the voltage high one member saying to keep it at 15V. The specs say 13.8 V nominal during TX. (11 V min, 15 V max) I would think that the transmit signal should be fairly clean within this range. At home its on a regulated supply 13.8 so NP but at the cottage where there is no utility power its on a battery with 6 and 10ga wiring all using solar charge. At night I will see voltages drop to about 12V after operating with lighting from the same battery for a while usually about 1:00 am in a contest. this is when I go off the air and to bed, as this is typically about when the battery reaches a 40-50% charge and I don't like to go below this. is operating approaching 12 volts (transmit) really an issue? David Moes President: Peterborough Amateur Radio Club. [hidden email] VE3DVY, VE3SD On 12/22/2014 11:31, Jim Brown wrote: > On Mon,12/22/2014 7:05 AM, Greg Troxel wrote: >> Jim Brown <[hidden email]> writes: >> >>> I run a contesting station with two K3s driving power amps with a 10A >>> supply keeping the battery charged during the winter, and solar panels >>> doing it during the summer. >> What do you do about the voltage being 12.5ish instead of 13.8? Run the >> K3s at reduced power (because of the amps you are doing anyway)? Don't >> worry about extra IMD? Use a DC-DC converter to get 13.8V? > > Most of my contesting is done either at legal limit, with the K3s > driving an amp or at QRP. For NAQP, of course, i run 100W. Even at > 100W and 12.5V the K3 is pretty clean, and at the 40-50W level it > takes to drive my Ten Tec Titans, even cleaner. The measurements in > the link below were taken with my usual power setup. > > k9yc.com/P3_SpectrumMeasurements.pdf > > Someone mentioned using a solar charge controller. I'm using a GV MPPT > charge controller between my solar panels and the battery. It's RF > quiet. Most charge controllers make RF noise. GV makes several models > for different battery types, voltages, and current ratings. They are > available here. The company also seems to be a good place to buy Li > batteries. > > http://www.batteryspace.com/140w-10a-solar-charge-controller-with-mppt-for-lithium-batteries.aspx > > > 73, Jim K9YC > > 73, Jim K9YC > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by wa4ta
AGM batteries can be air freighted...nuff said on safety.
Gary Vk1ZZ K3, KX3, KPA500-FT, KAT500-FT,P3. On 23/12/2014 7:29 AM, "tom armour" <[hidden email]> wrote: > I use one of these power supplies with a battery backup module installed > (Model: SEC-1223BBM). I have a deep cycle battery attached to it. > http://www.samlexamerica.com/products/ProductDetail.aspx?pid=516The > hot-switches to battery is very nice when power fails. Also if you happen > to draw more than 25A it uses the battery for the difference from up to > 35A. It charges the battery at 5A with normal power.Tom - wa4ta > > > Date: Mon, 22 Dec 2014 13:51:52 -0600 > > From: [hidden email] > > To: [hidden email] > > Subject: Re: [Elecraft] K3 13.8 VDC power > > > > Wow, thanks to all for the greatly informative answers. I gleaned many > > good ideas from them. > > > > This is my concern; I am interested in protecting my K3 from damage by > > not being shut down properly should a power interruption occur while the > > K3 is operating. For this design, I'm thinking about a worst case > > scenario; in transmit mode at 100 watts/20 amps, plus accessories on. > > > > I am concerned about Hydrogen gas while charging a lead-acid battery > > here in the furnace room. Since I don't need to operate by battery > > power, I'd like to know your thoughts about if a Gel-Cel battery of a 9 > > amp variety would handle the 20 amp load until I could go to receive > > mode and properly shut down? > > I haven't had any experience drawing that much amperage from a gel-cel > > momentarily. I don't know if the load voltage would be adequate to keep > > the K3 alive. I'd need to test it using an older style radio. I'm > > hoping someone has had experience related to this. > > > > Thanks in advance for comments, > > > > Dick, n0ce > > > > > > On 12/22/2014 1:31 AM, Richard Fjeld wrote: > > > Is anyone floating a battery across their power distribution? > > > > > > Dick, n0ce > > > > > > > > > > ______________________________________________________________ > > Elecraft mailing list > > Home: http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/mmfaq.htm > > Post: mailto:[hidden email] > > > > This list hosted by: http://www.qsl.net > > Please help support this email list: http://www.qsl.net/donate.html > > Message delivered to [hidden email] > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by ve3dvy
David,
I think the answer to your question is a matter of degree. I do not have any specific test data on the IMD increase as the DC voltage is reduced, but it is a fact that the IMD with 'nominal 12 volt' transceivers will worsen as the voltage drops. The fact that the K3 IMD is better than most other transceivers also says that the IMD as the voltage goes down is better on the K3 than others. If you are concerned about it, I suggest you reduce the power to something like 75 or 80 watts when your power source voltage decreases. The difference between that power and 100 watts is likely not to be noticed by the receiving stations. 73, Don W3FPR On 12/22/2014 5:50 PM, david Moes wrote: > I'm just curios is there any real test data available showing what > IMD may be present at various supply voltages? I have heard many > comments on the reflector over the years saying to keep the voltage > high one member saying to keep it at 15V. The specs say 13.8 V > nominal during TX. (11 V min, 15 V max) I would think that the > transmit signal should be fairly clean within this range. > > At home its on a regulated supply 13.8 so NP but at the cottage > where there is no utility power its on a battery with 6 and 10ga > wiring all using solar charge. At night I will see voltages drop to > about 12V after operating with lighting from the same battery for a > while usually about 1:00 am in a contest. this is when I go off the > air and to bed, as this is typically about when the battery reaches a > 40-50% charge and I don't like to go below this. is operating > approaching 12 volts (transmit) really an issue? > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by Richard Fjeld
Well, more good information. Maybe I stand corrected. It's been nearly 4 years since I have read the manual, and my memory may have read more into the statements than it should have. I refer to page 13, right hand column, halfway down, entitled "POWER". There is a note that reads "To ensure correct save of operating parameters, turn the K3 off /before/ turning the power supply off." When I read that, I thought about the short duration power failures we experience. Page 44 touches on updating the nonvolatile memory correctly before shut-down either by the power switch, or in this case a 'PS0;' command via the RS232 interface. As you saw, there was a reply from a contester who had several power outages with multiple K3's without any troubles. That was good to learn of. I thought If I only use the battery for backup to shutdown, there should be a minimum of charging. I have been using a UPS on the AC supply, but I trust a float battery I can test on the DC. I may abandon the whole idea and stay with the UPS. Sometimes rejection is a good thing. Note: As I learn more about this radio, I appreciate the thought that went into it's design. Thanks for the posts, and the bandwidth. Dick, n0ce ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by ve3dvy
On Mon,12/22/2014 2:50 PM, david Moes wrote:
> I'm just curios is there any real test data available showing what > IMD may be present at various supply voltages? The link below is for a presentation that K6XX and I did to NCCC a year or so ago. See slide #42 for some measurements that Bob did. http://k9yc.com/K6XXAmpTalk.pdf The measurements I posted a day or two ago were done at supply voltages between about 12.5V and 12.9V. It's hard to find the IMD -- there's some, but it's WAY down. 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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