Re: [Elecraft] Solar Power for KX3
Up here in Alaska I had a few experiences using solar powered remote communication systems. I worked a couple years for the BLM Wildfire Center (Fairbanks) radio shop and we had some 5w GE repeaters installed in big fiberglass boxes with a square solar panel attached to the cover. We would just take them out to a location (usually a hill or mountain top) and set them on the tundra with the panel facing straight up. The panels never got direct sun but averaged about 70% of peak all thru the long arctic summer (20+ hours). I'm guessing the panel was about 20-30w. One summer/fall I worked for a bush PBS TV station (KYUK Bethel, AK) maintaining remote TV translators. Many ran on solar panels which were installed vertical on the side of plywood sheds that housed the equipment. The theory was the max solar power was needed in winter with short daylight near the horizon;' during the summer the sun was high but days were long so average power was much more. These were 2-3 30w panels for running 10w TV translators 100% transmitting an AM video carrier. My last work involved remote repeater sites only accessible by air *helo*. They ran on huge alkaline battery banks (10,800 AH) but had 200AH batteries with 60w panels recharging them in summer. Automatic voltage sensed switching changed over from solar to the alkaline plant. These panel were faced south at the optimum solar angle between noon and sunrise/sunset. For a portable backpack system one will have to rely on frequent repointing to keep the panel in optimum sun. Interestingly an overcast summer day has 70% of the sun's power on a clear day. A flexible solar panel can be rolled and carried in a tube. 73, Ed - KL7UW __ 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
Re: [Elecraft] Solar Power for KX3
Panels are rated for a standard sun (1000 W/m^2 insolation) at I think 25C. This is for the maximum power point, which is almost never the voltage to charge the battery at. The ones I've played with (powerfilm 5W, HQRP 20W) do more or less make their rated power in full sun (really blue sky), and 5-20% of that in clouds. I have a 20W panel with not particularly good siting that gets sun from about 1030 to about 1600. I have seen 1.3A from it, charging a 12V AGM battery with a simple on/off controller (brunton). Over the last 2 months I have gotten an average of just over 3 Ah per day. On really sunny days I get 7Ah. So a solar setup really needs enough batteries to run for most of a week (at least in New England), and enough panel to recharge if you have 1.5 sunny days in that week. So for a fixed installation take daily use in Ah multiply by about 15 (1 week, don't discharge more than half) to get battery capacity take daily use in Ah, multiply by 2h of average good sun per day, and find a panel that can produce that current in full sun. All that said, I have taken a single 7Ah battery and the 20W panel with charge controller, and found that in mostly sunny conditions that powers a kx3 indefinitely just fine. Do not even think of using a panel without a charge controller. You will end up with excessive voltage and fry the battery. 73 de n1dam __ 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
Re: [Elecraft] Solar Power for KX3
I suspect you're going to have to reinvent at least some of the wheel. I have a 10-watt panel I got several years ago and have used to power a K2 at several Field Days. It generates 0.5 amps at up to 20 volts in strong sunlight. Lower light intensity reduces the voltage but the amps stay constant. I run it into a charge controller (a kit from someone on this list), then a gel-cell battery in parallel with the K2. Running overnight, not very intensely, the battery is fully charged again at the end of FD. Lead batteries are very robust about charging, and I don't know if the controller in the KX3 can accept this kind of wide-ranging power. My panel is small and light, and is mounted in a nylon cover with a zipper -- it's two panels which fold up. It was about $100 -- cheap at the time. Looking around the web, there are folding amorphous silicon panels for backpacking, for a lot of money, and larger, cheaper, heavier panels from places like Home Depot and Northern Tools. Kits are available. You'll need a silicon panel, a reverse-voltage protection diode, and some kind of charge controller if the KX3 doesn't already do that. I'd like to hear about your results. Peter W0LLN On Thu, Apr 18, 2013 at 3:28 PM, jimk...@aol.com wrote: Rather than reinvent the wheel, does anybody have experience or suggestions for a small solar array sufficient to keep a KX3 with internal batteries going during daylight? I would assume 10 watts average over a reasonable TX duty cycle would be enough.? Something strong enough or flexible enough to withstand packing for air travel would be desirable. 73?? -? Jim?? K8MR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Solar Power for KX3
From personal experience with the KX3 and solar panels, a 10 watt panel simply won't keep up. A 20 watt panel is fine on a bright sunny day if you shift its position and angle several times during the day. But I now use a 30 watt folding panel which has been adequate even on slightly overcast days to keep the battery fully charged, and I don't have to worry about moving it around all the time (I can just lay it flat on the ground rather than trying to match the exact sun angle). Of course if it was black-sky stormy, don't expect to keep up, and if it is winter time, lying it flat on the ground isn't a good choice given the low sun angles. I've run the KX3 in contest mode for several long contests and the average current draw over the entire contest has bee 300 mA (for 5 watts output). Bumping the power up to 10 watts brings that average drain to about 400 mA. 73, Bob, WB4SON __ 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
Re: [Elecraft] Solar Power for KX3
I'm using two solar setups. One is a 100W system for the K3 and KX3 / ham station generally. That's probably not going to interest anyone for portable ops with the KX3. Five or so years ago, I bought 80 4.5-inch wafers from a 2nd tier outfit in New England. From these, I built two panels that supply 21V with no load, and output is about 18W each. The panels were designed to strap on the rear of a backpack and they're about 16 x 28. I've used them only a few times as this transport arrangement is a bit clumsy and maneuvering is difficult with that type of unwieldy backpack load. Now I only use them when I drive the operating location. I would recommend some of the more modern roll-up amorphous silicon PV modules. I've seen them at Field Day, but don't have any brand names. 73, matt W6NIA On Thu, 18 Apr 2013 16:28:52 -0400 (EDT), you wrote: Rather than reinvent the wheel, does anybody have experience or suggestions for a small solar array sufficient to keep a KX3 with internal batteries going during daylight? I would assume 10 watts average over a reasonable TX duty cycle would be enough.? Something strong enough or flexible enough to withstand packing for air travel would be desirable. 73?? -? Jim?? K8MR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Solar Power for KX3
The key here is a good charge controller. I use a mppt controller and it is 98 % efficient. Gets 30% for charge. Has 3 different charge rates and handles all battery types. My RV is also wind turbine and solar powered. I have 560 watt solar to my mppt charger, then to my 900 amp hr battery bank. At night the wind turbine (600 watts) takes over and charges my battery bank. ( aw living off the grid. ) On Apr 19, 2013 10:07 AM, Matt Zilmer mzil...@verizon.net wrote: I'm using two solar setups. One is a 100W system for the K3 and KX3 / ham station generally. That's probably not going to interest anyone for portable ops with the KX3. Five or so years ago, I bought 80 4.5-inch wafers from a 2nd tier outfit in New England. From these, I built two panels that supply 21V with no load, and output is about 18W each. The panels were designed to strap on the rear of a backpack and they're about 16 x 28. I've used them only a few times as this transport arrangement is a bit clumsy and maneuvering is difficult with that type of unwieldy backpack load. Now I only use them when I drive the operating location. I would recommend some of the more modern roll-up amorphous silicon PV modules. I've seen them at Field Day, but don't have any brand names. 73, matt W6NIA On Thu, 18 Apr 2013 16:28:52 -0400 (EDT), you wrote: Rather than reinvent the wheel, does anybody have experience or suggestions for a small solar array sufficient to keep a KX3 with internal batteries going during daylight? I would assume 10 watts average over a reasonable TX duty cycle would be enough.? Something strong enough or flexible enough to withstand packing for air travel would be desirable. 73?? -? Jim?? K8MR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Solar Power for KX3
I agree re the charge controller. I use a kit-built one from CirKits. Model: SCC3. It is uber-RF-quiet being a linear cc, and can handle 20A. 73, matt W6NIA On Fri, 19 Apr 2013 10:30:57 -0500, you wrote: The key here is a good charge controller. I use a mppt controller and it is 98 % efficient. Gets 30% for charge. Has 3 different charge rates and handles all battery types. My RV is also wind turbine and solar powered. I have 560 watt solar to my mppt charger, then to my 900 amp hr battery bank. At night the wind turbine (600 watts) takes over and charges my battery bank. ( aw living off the grid. ) On Apr 19, 2013 10:07 AM, Matt Zilmer mzil...@verizon.net wrote: I'm using two solar setups. One is a 100W system for the K3 and KX3 / ham station generally. That's probably not going to interest anyone for portable ops with the KX3. Five or so years ago, I bought 80 4.5-inch wafers from a 2nd tier outfit in New England. From these, I built two panels that supply 21V with no load, and output is about 18W each. The panels were designed to strap on the rear of a backpack and they're about 16 x 28. I've used them only a few times as this transport arrangement is a bit clumsy and maneuvering is difficult with that type of unwieldy backpack load. Now I only use them when I drive the operating location. I would recommend some of the more modern roll-up amorphous silicon PV modules. I've seen them at Field Day, but don't have any brand names. 73, matt W6NIA On Thu, 18 Apr 2013 16:28:52 -0400 (EDT), you wrote: Rather than reinvent the wheel, does anybody have experience or suggestions for a small solar array sufficient to keep a KX3 with internal batteries going during daylight? I would assume 10 watts average over a reasonable TX duty cycle would be enough.? Something strong enough or flexible enough to withstand packing for air travel would be desirable. 73?? -? Jim?? K8MR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Solar Power for KX3
MPPT Controllers (small capacity) are few and far between and expensive. Several are actually PWM, are falsely marketed as MPPT, making the situation complicated. A MPPT controller can produce about 30% more power from a given solar panel during the summer months and about 10% more during the winter months. But it may be difficult to justify the substantial cost increase for smaller panels -- ask the question are you better off spending $100 more for a MPPT controller to get 3 watts more out of a 10 watt panel, or spending $100 to buy a 20 watt panel? The BuddiPole charge controller may be ideal for a KX3 user. It is very small, will work with LiFePO4 batteries or SLAs, and it isn't particularly expensive. But as others have said, using a charge controller is critical. http://www.buddipole.com/sobaco.html 73, Bob, WB4SON __ 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
Re: [Elecraft] Solar Power for KX3
I have two solar panels mounted together that I got, along with a 36AH SLA battery for running our Colman camp cooler (5A draw) on road trips. The panels together supply about 7.5A at 12-18V and will fit on the roof rack of our 4Runner. I also have a made in China charge controller for the setup which includes low voltage cutoff. (All of these pieces came from Jameco.) Having decided that it was wasteful to only use them on trips, I put the panels on the roof and am using them to run the K3/10+P3. This setup is good enough to run the radio on receive all night. (I haven't tried it during our rainy season.) I hope it will run well for field day. Cheers - Bill AE6JV --- Bill Frantz| If the site is supported by | Periwinkle (408)356-8506 | ads, you are the product.| 16345 Englewood Ave www.pwpconsult.com | | Los Gatos, CA 95032 __ 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
Re: [Elecraft] Solar Power for KX3
A side note for those attending Dayton. There has been a company that manufactures solar panels for the government at Dayton the last couple of years. They sell blemished panels that are used as panels in tents for power that would work perfectly for the KX3. I've got two of them and use them to charge my cell phone and run an electric cooler while out in backwoods. Forget the name of the company but they set up close to the M2, Green Herron rotor control, Array solutions booths. Dr. William J. Schmidt - K9HZ / J68HZ/ 8P6HK/ ZF2HZ Owner - Operator Big Signal Ranch Staunton, Illinois email: b...@wjschmidt.com -Original Message- __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] Solar Power for KX3
Rather than reinvent the wheel, does anybody have experience or suggestions for a small solar array sufficient to keep a KX3 with internal batteries going during daylight? I would assume 10 watts average over a reasonable TX duty cycle would be enough.? Something strong enough or flexible enough to withstand packing for air travel would be desirable. 73?? -? Jim?? K8MR __ 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
Re: [Elecraft] Solar Power for KX3
Jim: Be careful what you ask for. Solar arrays are not rated for average. Probably because there is no such thing as an average sun. I'd like to say they are rated for peak power but that is somewhat illusionary too. How much power you actually get from an array depends on many things. You will want to get some sort of charge controller for sure. That is so you can match the charging requirements of your rig and battery to the array. DO NOT expect them to be the same without a controller. I will offer a little data I collected on a 12x18 array in Southern California in June. I had a rig and 7AH gel cell in parallel. My peak solar current was 225ma (.225 x 13.8 = 3.1w) and the rig was drawing right at 200ma in receive. That meant I was pushing 25ma into the battery to replace what I used on transmit. If I could have kept that going I would have been happy. I used the ammeter to aim the array at the sun. The problem is the sun is always moving. In twelve minutes my array power was down to less than 1 watt output. That meant after five minutes I was taking power out of the gel cell to help power the receiver. If I really wanted to charge the battery I had to turn the rig off. Ratings: The manufacturer rated the array at 5 watts but they said it was the equivalent of a 10 watt array by using their controller. This was a glass covered array not suitable for back packing. If I were back packing I would want the more expensive roll-up arrays. Then you need a frame to hang them in. I have never seen any guaranteed ratings on solar arrays. Caveat Emptor. 73, Fred, AE6QL -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of jimk...@aol.com Sent: Thursday, April 18, 2013 1:29 PM To: elecraft@mailman.qth.net Subject: [Elecraft] Solar Power for KX3 Rather than reinvent the wheel, does anybody have experience or suggestions for a small solar array sufficient to keep a KX3 with internal batteries going during daylight? I would assume 10 watts average over a reasonable TX duty cycle would be enough.? Something strong enough or flexible enough to withstand packing for air travel would be desirable. 73?? -? Jim?? K8MR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Solar Power for KX3
This Fred will second the other Fred. My engineering team designed a solar system for 4 repeater stations for a pipeline communications system in S. Africa. It was hugely overdesigned, we had to to meet the contract specs. In full sun, it made over 200A, way more than the wet glass batteries needed or could handle, and we had to have a controller that would sink all that power. 90 mins later, it was down to 110A, and 60 min later it was down to 60A which just about shouldered the site load. Be careful in your plans. For a field operation, it's great, and it works well. I was visiting my college roommate while they were building a straw bale house, and one morning, there was no generator noise. Turned out they had a solar trailer [I have a photo if anyone is interested], it was bright and sunny, they could move the trailer, and it seemed to power their skill saws and drills. 73, Fred K6DGW - Northern California Contest Club - CU in the 2013 Cal QSO Party 5-6 Oct 2013 - www.cqp.org On 4/18/2013 8:39 PM, Fred Townsend wrote: Jim: Be careful what you ask for. Solar arrays are not rated for average. Probably because there is no such thing as an average sun. I'd like to say they are rated for peak power but that is somewhat illusionary too. How much power you actually get from an array depends on many things. You will want to get some sort of charge controller for sure. That is so you can match the charging requirements of your rig and battery to the array. DO NOT expect them to be the same without a controller. __ 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
