A Fully Rechargeable Satellite Station
Hey everyone,
Over the past 10 months, I’ve made some great new friendships - thanks to AMSAT and its good work to keep amateur radio in space. Many of those friends know that I’ve chosen “a different path to orbit” in my desire to incorporate the concept of emergency communications.
FCC Part 97 is unambiguous in noting that Amateur Radio operators’ abilities to serve the public through provision of emergency communications are, collectively, the lynchpin of the service in the United States. The more I learned about the satellites we all love, the more it became clear to me that it had to be possible to assemble an effective “emergency” station that would be true to that purpose. I began thinking of it as my rechargeable station.
By 03:15 UTC on 27 April, that possibility became a reality. Over the course of the day Sunday and into Monday (UTC), I was fortunate to work multiple contacts in SSB on AO-7, FO-29 and VO-52 using a totally portable (but full-featured) station running on full emergency power. How do I define “full-featured” in this context? My station operates full duplex, incorporates computer-controlled Doppler tuning, and can work CW, SSB, packet and all the digital modes while running on rechargeable batteries.
Sunday started out with a pleasant surprise – DJ8NY in CW on AO-7, making Germany the fourth European country to find Georgia on AO-7 in the past 10-or-so days. Oh … no; I was NOT running full battery power. Given my approach to the antenna here, those low-angle passes of AO-7 call for more than the 5 watts my fully rechargeable station can muster, so I transmit using a Yaesu FT-857D, which provides up to 20 watts out on 70 cm. I need the extra rf muscle because I work AO-7 from my shack, in a second-floor bedroom of my home, and I hand-hold my Elk log periodic antenna. Reaching the satellite when Europe and EM84 share the footprint have me pointing the Elk at a windowless wall, generally at the northeast corner of the house.
The rest of Sunday (and into Monday, UTC), I replaced the FT-857D with a Yaesu FT-817ND for transmitting. Another FT-817ND served as my receiver, as it always does (even with the 857). I use a Diamond MX-72H duplexer to connect both radios to the Elk, and use about 6 feet of RG-8X between the duplexer and the antenna. I have not yet used a receive preamp on either 2 meters or 70 centimeters. Both radios used their internal battery packs for power, as did the Acer Aspire One netbook computer I picked up last fall specifically for radio use. I have been able to configure Orbitron, SatPC 32 and Ham Radio Deluxe (Version 4.1 beta, with the Satellite Tracker software) to provide computer-controlled Doppler tuning.
With multiple CW contacts already in the log on all three satellites using the fully rechargeable station, I wanted to complete the exercise by adding SSB contacts on all three linear satellites in the same day. Thanks to Angelo (N5UXT), Leo (W7JPI), Art (K4YYL), Joe (K3SZH), Bob (KC9ICH) and everyone else I worked Sunday for their signal reports and encouragement. It was pretty neat heading to bed knowing that I had a station I could take down and set up anywhere in a matter of minutes (excluding travel time, of course) that I could use to effectively work virtually any mode available to U.S. amateurs from 40 meters through 70 cm, including all the satellites.
I mention the HF bands and use the phrase “virtually any mode” because I picked up a screwdriver vertical last fall too, and have used it or an end-fed longwire (with a manual MFJ tuner) and a Signal Link USB to make contacts using a variety of sound-card based digital modes, including PSK-31, Olivia, RTTY and SSTV. Having been totally inactive from early 1992 until about 2 years ago, I continue to be amazed at all we amateurs have to enjoy on the air.
My ISS contacts will always be my best QSOs ever. But working Europe on AO-7 and routinely making multiple contacts on passes of all of our satellites running 5 watts rf out or less – all of them with a handheld antenna and many of them from inside – won’t ever get old.
When I told Angelo what I was up to on Sunday during our FO-29 contact, he told me I needed to write it up for the AMSAT-BB. So … here it is.
My primary motivation to share all of this is to suggest to anyone who’s interested that ALL of our amateur satellites are routinely workable from stations that don’t have all the bells and whistles. They don’t even need a lot of power.
Go to the AMSAT Web site (www.AMSAT.org) and look through the descriptions of the satellites we all can work daily. With the exception of the ISS, every satellite we work is transmitting to Earth using QRP power levels – even AO-7. And none of them are using “optimum” antenna systems offering lots of gain and directivity.
Ten months ago today (28 June, 2008), I had my first-ever satellite contact – with KD8ILL in EM99 on AO-51. We both used handheld stations. I never imagined that what started with a brief QSO would have led to so many wonderful contacts and new friendships.
73 to all,
Tim – N3TL Athens, Ga. – EM84ha
Hi Tim,
This is great; I've thought about the off-grid aspects of the hobby as well (but not done much about it yet).
One question... what accommodations have you made for the recharging of the batteries? Given that AC power may not be available for some time (longer than one charge), do you use a 12v (automobile) -> 120vac inverter and regular charge equipment, or something custom? I know some radios can run from AA dry cells (e.g. my Kenwood TH-D7, and the HP-100LX Palmtop which I can run FODTrack on), but not the laptop.
Just curious,
Greg KO6TH
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Hey Greg,
In addition to the internal rechargeable pack, Yaesu provides a battery tray for a "DIY" battery pack, and I have been assembling rechargeable individual batteries for these trays. In the case of a longterm power outage, it occurs to me that, as you suggest, a larger 12v battery could come into play. The regular power supply I use in the shack includes the provision to connect a gel cell battery for charging and backup, so that's one option. An auto battery certainly is another although, I suspect I'd opt for a deep-cycle marine battery (or batteries) if I was going to buy them for this use.
My intial plan would be to have enough internal-battery power to get through at least two "cycles" (i.e., at least two battery packs ready to go for each radio). The hope is that accesss to power from a generator or the larger batteries would be available for recharging the batteries and powering the radios.
As for the computer, the 6-cell pack that is available for the Acer is a lithion ion pack that, when fully charged, provides up to six hours of continuous use. Given the nature of our satellite passes - in chunks of 10-15 minutes - I have been able to make days worth of passes without a recharge. I hope to pick up another 6-cell battery because I believe two of them would provide the power necessary to handle things until power was available for recharging.
Reading yours and some other comments have me thinking about a few more elements I need to look into ... things I hadn't given much thought to, but elements that would be helpful to know.
Both on and off the reflector, I've received multiple requests to write this up for the Journal, and that's very gratifying. I'll definitely do that, and thank everyone for their positive feedback.
73 to all,
Tim -------------- Original message from "Greg D." [email protected]: --------------
Hi Tim, This is great; I've thought about the off-grid aspects of the hobby as well (but not done much about it yet). One question... what accommodations have you made for the recharging of the batteries? Given that AC power may not be available for some time (longer than one charge), do you use a 12v (automobile) -> 120vac inverter and regular charge equipment, or something custom? I know some radios can run from AA dry cells (e.g. my Kenwood TH-D7, and the HP-100LX Palmtop which I can run FODTrack on), but not the laptop.
Just curious,
Greg KO6TH
Rediscover Hotmail®: Get e-mail storage that grows with you. http://windowslive.com/RediscoverHotmail?ocid=TXT_TAGLM_WL_HM_Rediscover_Sto... 2_042009 _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
A quick inquiry about running a laptop directly off of a cigarette outlet in the car...
for example...let's consider the HP/Compaq series of laptops that take 16-19V from their chargers/power supplies...
Can they be run directly from the auto's 13.6v supply...the available amperage always made me nervous...as does the voltage swings when starting and out of the regulator.
Roger WA1KAT ----- Original Message ----- From: [email protected] To: "Greg D." [email protected]; [email protected] Sent: Wednesday, April 29, 2009 8:52 AM Subject: [amsat-bb] Re: A Fully Rechargeable Satellite Station
Hey Greg,
In addition to the internal rechargeable pack, Yaesu provides a battery
tray for a "DIY" battery pack, and I have been assembling rechargeable individual batteries for these trays. In the case of a longterm power outage, it occurs to me that, as you suggest, a larger 12v battery could come into play. The regular power supply I use in the shack includes the provision to connect a gel cell battery for charging and backup, so that's one option. An auto battery certainly is another although, I suspect I'd opt for a deep-cycle marine battery (or batteries) if I was going to buy them for this use.
My intial plan would be to have enough internal-battery power to get
through at least two "cycles" (i.e., at least two battery packs ready to go for each radio). The hope is that accesss to power from a generator or the larger batteries would be available for recharging the batteries and powering the radios.
As for the computer, the 6-cell pack that is available for the Acer is a
lithion ion pack that, when fully charged, provides up to six hours of continuous use. Given the nature of our satellite passes - in chunks of 10-15 minutes - I have been able to make days worth of passes without a recharge. I hope to pick up another 6-cell battery because I believe two of them would provide the power necessary to handle things until power was available for recharging.
Reading yours and some other comments have me thinking about a few more
elements I need to look into ... things I hadn't given much thought to, but elements that would be helpful to know.
Both on and off the reflector, I've received multiple requests to write
this up for the Journal, and that's very gratifying. I'll definitely do that, and thank everyone for their positive feedback.
73 to all,
Tim
I'm not sure how fully this answers your question and/or addresses your concern, but I've done a quick Google "poke around" and discovered a number of "cigarette plug" power options for laptops that all appear to be of high quality and rated to handle the power requirements in question.
I don't own such an adapter as I write this. But when I get one, I'll be as certain as I can that it is intended to work with the laptop I plan to use. Here, that most likely will be the Acer Aspire One. I hope this helps,
Tim -------------- Original message from "Roger Kolakowski" [email protected]: --------------
A quick inquiry about running a laptop directly off of a cigarette outlet in the car...
for example...let's consider the HP/Compaq series of laptops that take 16-19V from their chargers/power supplies...
Can they be run directly from the auto's 13.6v supply...the available amperage always made me nervous...as does the voltage swings when starting and out of the regulator.
Roger WA1KAT ----- Original Message ----- From: To: "Greg D." ; Sent: Wednesday, April 29, 2009 8:52 AM Subject: [amsat-bb] Re: A Fully Rechargeable Satellite Station
Hey Greg,
In addition to the internal rechargeable pack, Yaesu provides a battery
tray for a "DIY" battery pack, and I have been assembling rechargeable individual batteries for these trays. In the case of a longterm power outage, it occurs to me that, as you suggest, a larger 12v battery could come into play. The regular power supply I use in the shack includes the provision to connect a gel cell battery for charging and backup, so that's one option. An auto battery certainly is another although, I suspect I'd opt for a deep-cycle marine battery (or batteries) if I was going to buy them for this use.
My intial plan would be to have enough internal-battery power to get
through at least two "cycles" (i.e., at least two battery packs ready to go for each radio). The hope is that accesss to power from a generator or the larger batteries would be available for recharging the batteries and powering the radios.
As for the computer, the 6-cell pack that is available for the Acer is a
lithion ion pack that, when fully charged, provides up to six hours of continuous use. Given the nature of our satellite passes - in chunks of 10-15 minutes - I have been able to make days worth of passes without a recharge. I hope to pick up another 6-cell battery because I believe two of them would provide the power necessary to handle things until power was available for recharging.
Reading yours and some other comments have me thinking about a few more
elements I need to look into ... things I hadn't given much thought to, but elements that would be helpful to know.
Both on and off the reflector, I've received multiple requests to write
this up for the Journal, and that's very gratifying. I'll definitely do that, and thank everyone for their positive feedback.
73 to all,
Tim
Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
I have an old IBM thinkpad whose battery charger outputs 16vdc at 2.2amp. I cut the dc cord and installed some crimp-on eyelets so that it could attach to a small two terminal strip for which I made a cigarette lighter cord. I was able to run that computer charging off my wife's Ford minivan for the 6000 mile trip from MS to AK in spring of 2004. The vehicle voltage is damped by the car's battery and runs about 14.2 volts when the engine is running and sags to 13.2v when off. I never had the computer running when starting the engine. The computer battery will also act as a huge capacitor for smoothing out any voltage spikes.
I also ran my FT-817, 45w amp, KPC-3, and Garmin GPS from the car's battery. The Garmin requires 3.2 volts which was easily provided using a voltage-regulator.
Most cigarette lighters circuits have a 15 to 20 amp fuse on them. That ought to work fine for charging/using with your computer.
73, Ed - KL7UW
At 06:34 AM 4/29/2009, Roger Kolakowski wrote:
A quick inquiry about running a laptop directly off of a cigarette outlet in the car...
for example...let's consider the HP/Compaq series of laptops that take 16-19V from their chargers/power supplies...
Can they be run directly from the auto's 13.6v supply...the available amperage always made me nervous...as does the voltage swings when starting and out of the regulator.
Roger WA1KAT ----- Original Message ----- From: [email protected] To: "Greg D." [email protected]; [email protected] Sent: Wednesday, April 29, 2009 8:52 AM Subject: [amsat-bb] Re: A Fully Rechargeable Satellite Station
Hey Greg,
In addition to the internal rechargeable pack, Yaesu provides a battery
tray for a "DIY" battery pack, and I have been assembling rechargeable individual batteries for these trays. In the case of a longterm power outage, it occurs to me that, as you suggest, a larger 12v battery could come into play. The regular power supply I use in the shack includes the provision to connect a gel cell battery for charging and backup, so that's one option. An auto battery certainly is another although, I suspect I'd opt for a deep-cycle marine battery (or batteries) if I was going to buy them for this use.
My intial plan would be to have enough internal-battery power to get
through at least two "cycles" (i.e., at least two battery packs ready to go for each radio). The hope is that accesss to power from a generator or the larger batteries would be available for recharging the batteries and powering the radios.
As for the computer, the 6-cell pack that is available for the Acer is a
lithion ion pack that, when fully charged, provides up to six hours of continuous use. Given the nature of our satellite passes - in chunks of 10-15 minutes - I have been able to make days worth of passes without a recharge. I hope to pick up another 6-cell battery because I believe two of them would provide the power necessary to handle things until power was available for recharging.
Reading yours and some other comments have me thinking about a few more
elements I need to look into ... things I hadn't given much thought to, but elements that would be helpful to know.
Both on and off the reflector, I've received multiple requests to write
this up for the Journal, and that's very gratifying. I'll definitely do that, and thank everyone for their positive feedback.
73 to all,
Tim
Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
To say I am amazed is not doing the English language justice, 6000 Miles from Ms to AK must have been via a round about route indeed. My Driving recollections would guess it is more like 3800 miles from St. Lou to Anchorage... But then I was not in your mini van or shoes...
However the real comment is this, why don't you just get a 40 dollar inverter, plug it into the ciggie lighter hole or hard wire it and you have all the commercial type (117VAC) power you need, I ran one in my semi for years, have one in my Dodge Nitro and it powers my Dell Laptop, The HP printer/scanner I use for my business, charges my cell phone, razor and anything else I need up to a 800 watts of power. Rather than trying to re invent the wheel, why not use the technology that is available, and in common usage by almost every truck driver in the USA.
DE Jack KD1PE
I was able to run that computer charging off
my wife's Ford minivan for the 6000 mile trip from MS to AK in spring of 2004. The vehicle voltage is damped by the car's battery and runs about 14.2 volts when the engine is running and sags to 13.2v when off. I never had the computer running when starting the engine. The computer battery will also act as a huge capacitor for smoothing out any voltage spikes.
Most cigarette lighters circuits have a 15 to 20 amp fuse on them. That ought to work fine for charging/using with your computer.
73, Ed - KL7UW
Sorry if this slightly non-satellite chatter:
Lots of folks are amazed how far Alaska is from anywhere. Well, it is 2400-miles by road from Seattle to Anchorage (traveling over the Alaska Hwy). We traveled west from Pass Christian, MS (about 50-miles east of New Orleans) on I-10 to southern California and then up I-5 to the Canadian border. If you look at a map of US roads there are no tangental roads from the south to the NW so one will travel west then north then west then north, whatever route you take. It is something like 1800-miles from LA to the Canadian border, alone. We did a small detour over to the Oregon coast which added a couple hundred miles. The trip took 22-days. We took one day off in Gold Beach , OR for clothes washing and visiting with my wife's mother whom she had not seen in ten years. BTW I live on the same longitude (151)as Hawaii (152). photos of the van are here (scroll to bottom of page): http://www.kl7uw.com/mw10g.htm
I spent about $10-15 on my wiring vs. $150+ for an AC inverter. nuff said!
73, Ed
At 07:12 AM 4/29/2009, Jack K. wrote:
To say I am amazed is not doing the English language justice, 6000 Miles from Ms to AK must have been via a round about route indeed. My Driving recollections would guess it is more like 3800 miles from St. Lou to Anchorage... But then I was not in your mini van or shoes...
However the real comment is this, why don't you just get a 40 dollar inverter, plug it into the ciggie lighter hole or hard wire it and you have all the commercial type (117VAC) power you need, I ran one in my semi for years, have one in my Dodge Nitro and it powers my Dell Laptop, The HP printer/scanner I use for my business, charges my cell phone, razor and anything else I need up to a 800 watts of power. Rather than trying to re invent the wheel, why not use the technology that is available, and in common usage by almost every truck driver in the USA.
DE Jack KD1PE
I was able to run that computer charging off
my wife's Ford minivan for the 6000 mile trip from MS to AK in spring of 2004. The vehicle voltage is damped by the car's battery and runs about 14.2 volts when the engine is running and sags to 13.2v when off. I never had the computer running when starting the engine. The computer battery will also act as a huge capacitor for smoothing out any voltage spikes.
Most cigarette lighters circuits have a 15 to 20 amp fuse on them. That ought to work fine for charging/using with your computer.
73, Ed - KL7UW
Tripp Lite PV375 PV 375W 12V DC to AC Portable Inverter with DC Auto Power Outlet
$45.24 at Amazon.com....
TRIPPLITE PV150 150-Watt Power Inverter
$39.95
For roughly 10% of the cost of the computer (or considerably less in the case of my Dells) and the flexibility of being able to plug in basically anything I would normally use (camera battery charger comes to mind) and having the correct voltage, I'll spring for the extra $$$.
73 de Tim, K4SHF LM 2336
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Edward Cole Sent: Wednesday, April 29, 2009 9:45 PM To: [email protected] Subject: [amsat-bb] Re: A Fully Rechargeable Satellite Station
Sorry if this slightly non-satellite chatter:
Lots of folks are amazed how far Alaska is from anywhere. Well, it is 2400-miles by road from Seattle to Anchorage (traveling over the Alaska Hwy). We traveled west from Pass Christian, MS (about 50-miles east of New Orleans) on I-10 to southern California and then up I-5 to the Canadian border. If you look at a map of US roads there are no tangental roads from the south to the NW so one will travel west then north then west then north, whatever route you take. It is something like 1800-miles from LA to the Canadian border, alone. We did a small detour over to the Oregon coast which added a couple hundred miles. The trip took 22-days. We took one day off in Gold Beach , OR for clothes washing and visiting with my wife's mother whom she had not seen in ten years. BTW I live on the same longitude (151)as Hawaii (152). photos of the van are here (scroll to bottom of page): http://www.kl7uw.com/mw10g.htm
I spent about $10-15 on my wiring vs. $150+ for an AC inverter. nuff said!
73, Ed
At 07:12 AM 4/29/2009, Jack K. wrote:
To say I am amazed is not doing the English language justice, 6000 Miles from Ms to AK must have been via a round about route indeed. My Driving recollections would guess it is more like 3800 miles from St. Lou to Anchorage... But then I was not in your mini van or shoes...
However the real comment is this, why don't you just get a 40 dollar inverter, plug it into the ciggie lighter hole or hard wire it and you have all the commercial type (117VAC) power you need, I ran one in my semi for years, have one in my Dodge Nitro and it powers my Dell Laptop, The HP printer/scanner I use for my business, charges my cell phone, razor and anything else I need up to a 800 watts of power. Rather than trying to re invent the wheel, why not use the technology that is available, and in common usage by almost every truck driver in the USA.
DE Jack KD1PE
I was able to run that computer charging off
my wife's Ford minivan for the 6000 mile trip from MS to AK in spring of 2004. The vehicle voltage is damped by the car's battery and runs about 14.2 volts when the engine is running and sags to 13.2v when off. I never had the computer running when starting the engine. The computer battery will also act as a huge capacitor for smoothing out any voltage spikes.
Most cigarette lighters circuits have a 15 to 20 amp fuse on them. That ought to work fine for charging/using with your computer.
73, Ed - KL7UW
_______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
participants (6)
-
Edward Cole -
Greg D. -
Jack K. -
n3tl＠bellsouth.net -
Roger Kolakowski -
Tim Tapio