Re: Topband: Remote pre-amp power source
If the pre-amp point is readily accessible and in a not easy spot to get consistent sunlight (e.g. dense forest), it sometimes makes more economic sense to use dry cells and/or rechargeable batteries that can be swapped out for recharging every few days. P.S. I work in an industry that until very recently used No. 6 cells for some remote applications :-) Tim N3QE On Thu, Sep 25, 2014 at 1:30 PM, wrote: > Anyone using, or know of a source, for a compact battery with solar cell > charger, to power a remote antenna pre-amp ? > (Not looking to power up through the coax cable) > > 73 > Bruce-K1FZ > www.qsl.net/k1fz/pennantnotes.html > > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Remote pre-amp power source
Something to keep in mind Even in a quiet location with a -10 dBd gain very directional antenna, the preamp can be thousands of feet from the antenna on 160 with no ill effects. My eight vertical array, for example, has about 600 feet of F6, then 2000 feet of F11, then the preamp. It limits on propagated noise even in daylight. Of course there are things that might make a remote amplifier useful, such as very lossy feedlines and very low gain antennas, but even 3000 feet of F11 type cable between antenna and preamp isn't an issue with normal antennas. What might be an issue is a compact loop or other very negative gain antenna. - Original Message - From: To: "Don Kirk" Cc: "Topband" Sent: Thursday, September 25, 2014 2:55 PM Subject: Re: Topband: Remote pre-amp power source Hi Don, Pre-amp requires 12-18 volts at 130ma. (low band DXing- nightime use) This solar charger puts out 20 volts that could be reduced to 15 volts with a three legged regulator. I was hoping to find a pre-assembled charger & battery, but may have to build one. http://www.harborfreight.com/15-watt-solar-battery-charger-68692.html 73 Bruce-K1FZ What is the operating current and voltage of the preamp you plan to use? Since it sounds like the preamp will be powered on all the time this information will be key in the selection of the battery capacity and solar panel rating. Don (wd8dsb) On Thu, Sep 25, 2014 at 1:30 PM, wrote: Anyone using, or know of a source, for a compact battery with solar cell charger, to power a remote antenna pre-amp ? 73 Bruce-K1FZ www.qsl.net/k1fz/pennantnotes.html _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband - No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4765 / Virus Database: 4025/8270 - Release Date: 09/25/14 _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Remote pre-amp power source
Hi Bruce, Their are numerous methods used for sizing solar panel systems, and using one of the common methods provides the following for your application as follows : Using a battery charging efficiency factor of 120%, and Portland Maine as the location (winter average = 3.56 sun hours/day) . And designing for a reserve capacity of 3 days (3 days of no sun), with a minimum battery capacity of 50%. If designing for continuous power applied to the preamp (24 hours per day) : Required battery capacity = 18.7 Ah, Solar panel = 1.05 amps (almost a 20 watt panel). If designing for 15 hours of continuous service (using a day/night controller) : Required battery capacity = 11.7 Ah, Solar Panel = 0.66 amps (approximately a 10 watt panel). The above method is somewhat simplistic (does not take into account how cold temperature impacts the capacity of the battery, etc.), nevertheless it provides some reasonable numbers to put things into perspective. I'm sure you will think the panel and battery are large, but that's what it takes to handle continuous service during the winter when day light is minimum. Note : solar panels really operate like a constant current source versus a constant voltage source, therefore a typical solar panel for 12 volt battery charging will have an open circuit voltage of around 21 volts but this is under a zero output current condition. The maximum output current of a solar panel is when you have it's output short circuited but it's current at max power is not much less than its short circuit current. An easy way to characterize what kind of panel you have is to measure under bright sunlight the short circuit current, and the open circuit voltage of the panel. Don (wd8dsb) On Thu, Sep 25, 2014 at 2:55 PM, wrote: > > Hi Don, > > Pre-amp requires 12-18 volts at 130ma. (low band DXing- nightime use) > > This solar charger puts out 20 volts that could be reduced to 15 volts > with a three legged regulator. I was hoping to find a pre-assembled > charger & battery, but may have to build one. > http://www.harborfreight.com/15-watt-solar-battery-charger-68692.html > > 73 > Bruce-K1FZ > > What is the operating current and voltage of the preamp you plan to > use? Since it sounds like the preamp will be powered on all the time this > information will be key in the selection of the battery capacity and solar > panel rating. > Don (wd8dsb) > > On Thu, Sep 25, 2014 at 1:30 PM, wrote: > > Anyone using, or know of a source, for a compact battery with solar > cell charger, to power a remote antenna pre-amp ? > 73 Bruce-K1FZ > www.qsl.net/k1fz/pennantnotes.html > > _ > Topband Reflector Archives - http://www.contesting.com/_topband > > > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Remote pre-amp power source
On Thu,9/25/2014 11:55 AM, k...@myfairpoint.net wrote: I was hoping to find a pre-assembled charger & battery, but may have to build one. Don't count on anything from Harbor Freight being RF-quiet. :) Here's a simple hysteresis-type charge controller that is RF-quiet. It's also cheap -- $20. It's not as efficient as the Genesun, but may be enough to run a preamp, depending on the panel(s) and battery. Remember that unless the preamp is switched on and off when not in use, that 130 mA becomes 3.1 Ah if runing 24/7. And if your use is mostly during the winter, take into account that days are shorter and sometimes not very bright. http://www.batteryjunction.com/sunforce-60012.html?gclid=CIe49eKK_cACFROTfgodl0oAJg 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Remote pre-amp power source
Hi Don, Pre-amp requires 12-18 volts at 130ma. (low band DXing- nightime use) This solar charger puts out 20 volts that could be reduced to 15 volts with a three legged regulator. I was hoping to find a pre-assembled charger & battery, but may have to build one. http://www.harborfreight.com/15-watt-solar-battery-charger-68692.html 73 Bruce-K1FZ What is the operating current and voltage of the preamp you plan to use? Since it sounds like the preamp will be powered on all the time this information will be key in the selection of the battery capacity and solar panel rating. Don (wd8dsb) On Thu, Sep 25, 2014 at 1:30 PM, wrote: Anyone using, or know of a source, for a compact battery with solar cell charger, to power a remote antenna pre-amp ? 73 Bruce-K1FZ www.qsl.net/k1fz/pennantnotes.html _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Remote pre-amp power source
On Thu,9/25/2014 10:56 AM, Jim Brown wrote: Lots of batteries, chargers, and solar charge controllers here. http://www.batteryspace.com/ I forgot to mention that the Genasun GV-series MPPT charge controllers are RF quiet. They make 5A and 10A controllers for Lead-Acid, Li-Ion, and LiFePO4 batteries. They are US-made, and not cheap. 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Remote pre-amp power source
On Thu,9/25/2014 10:30 AM, k...@myfairpoint.net wrote: Anyone using, or know of a source, for a compact battery with solar cell charger, to power a remote antenna pre-amp ? (Not looking to power up through the coax cable) Lots of batteries, chargers, and solar charge controllers here. http://www.batteryspace.com/ The company is based in the SF Bay Area, and is the US partner of a small (by Chinese standards) Chinese battery manufacturer. The Chinese company makes the individual cells, the US company packages them for a very wide range of applications and sells them. My neighbor, W6GJB, bought one of their LiFePO4 packs for use with his KX3 and KXPA100 that looks quite solid. Choose the battery technology you want to use, then the voltage range, and you get a page of packs with many different package sizes and current ranges. Many of the packaging differences are made to fit as replacements for custom packs in all sorts of equipment. 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Remote pre-amp power source
Anyone using, or know of a source, for a compact battery with solar cell charger, to power a remote antenna pre-amp ? (Not looking to power up through the coax cable) 73 Bruce-K1FZ www.qsl.net/k1fz/pennantnotes.html _ Topband Reflector Archives - http://www.contesting.com/_topband
