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#1
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Hi,
I'm trying to determine if I could use 10 meters to contact a station about 75 miles away with about 2500ft elevation of a couple sets of hills in between with just simple antennas on either end. Perhaps a 10m dipole on one end and some kind of stealthy one on the other. I assume this would have to be ground wave only given the distance and current band conditions. My parents are both techs so we're currrently limited to parts of 10m as the lowest band and I'd like to have something reliable without need repeaters for disaster comms. We actually only have a few single hop VHF/UHF repeaters between us, though quite a few linked ones. I've also thought of 6m due to smaller antenna requirements, but I'm pretty sure this is too far... Thanks! |
#2
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On Fri, 27 Apr 2007 08:47:55 -0700, Joey wrote:
Hi, I'm trying to determine if I could use 10 meters to contact a station about 75 miles away Hi Joey, That's hit number one, distance at this wavelength. with about 2500ft elevation of a couple sets of hills in between That's hit number two with the terrain against you. with just simple antennas on either end. That's hit number three, antennas without gain. Perhaps a 10m dipole on one end and some kind of stealthy one on the other. That's hit number four, every possibility of being cross polarized, and with at least one antenna masked by building or foliage to qualify as "stealthy." I assume this would have to be ground wave only given the distance and current band conditions. You might try NVIS, but what you say, as follows, doesn't give you many band options. My parents are both techs so we're currrently limited to parts of 10m as the lowest band It's time to upgrade. Consult the new rule changes, take a practice test, and see what happens. and I'd like to have something reliable without need repeaters for disaster comms. Then you really need to stop rationalizing about having a "stealth" antenna. If this was Hurricane Katrina, how long can you call CQ under water? We actually only have a few single hop VHF/UHF repeaters between us, though quite a few linked ones. I've also thought of 6m due to smaller antenna requirements, but I'm pretty sure this is too far... Try it first before giving up. 73's Richard Clark, KB7QHC |
#3
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I figured it was a long shot. By "stealth" i just mean something low
profile and the other end doesn't have much yard space and a big verticle is certainly not going to be sticking up on top. I suppose I could making something that's just deployable when needed since this isn't for day to day use... seems upgrading may help....thx... On Fri, 27 Apr 2007 09:25:17 -0700, Richard Clark wrote: On Fri, 27 Apr 2007 08:47:55 -0700, Joey wrote: Hi, I'm trying to determine if I could use 10 meters to contact a station about 75 miles away Hi Joey, That's hit number one, distance at this wavelength. with about 2500ft elevation of a couple sets of hills in between That's hit number two with the terrain against you. with just simple antennas on either end. That's hit number three, antennas without gain. Perhaps a 10m dipole on one end and some kind of stealthy one on the other. That's hit number four, every possibility of being cross polarized, and with at least one antenna masked by building or foliage to qualify as "stealthy." I assume this would have to be ground wave only given the distance and current band conditions. You might try NVIS, but what you say, as follows, doesn't give you many band options. My parents are both techs so we're currrently limited to parts of 10m as the lowest band It's time to upgrade. Consult the new rule changes, take a practice test, and see what happens. and I'd like to have something reliable without need repeaters for disaster comms. Then you really need to stop rationalizing about having a "stealth" antenna. If this was Hurricane Katrina, how long can you call CQ under water? We actually only have a few single hop VHF/UHF repeaters between us, though quite a few linked ones. I've also thought of 6m due to smaller antenna requirements, but I'm pretty sure this is too far... Try it first before giving up. 73's Richard Clark, KB7QHC |
#4
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![]() "Joey" wrote in message ... Hi, I'm trying to determine if I could use 10 meters to contact a station about 75 miles away with about 2500ft elevation of a couple sets of hills in between with just simple antennas on either end. Perhaps a 10m dipole on one end and some kind of stealthy one on the other. I assume this would have to be ground wave only given the distance and current band conditions. My parents are both techs so we're currrently limited to parts of 10m as the lowest band and I'd like to have something reliable without need repeaters for disaster comms. We actually only have a few single hop VHF/UHF repeaters between us, though quite a few linked ones. I've also thought of 6m due to smaller antenna requirements, but I'm pretty sure this is too far... Thanks! 75 miles is a bad distance for 10M I have almost no cotacts at that range. The few occured while doing mountain toping.. Great time to upgrade just get online and keep taking practice test until you pass. |
#5
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On Apr 27, 9:47 am, Joey wrote:
Hi, I'm trying to determine if I could use 10 meters to contact a station about 75 miles away with about 2500ft elevation of a couple sets of hills in between with just simple antennas on either end. Perhaps a 10m dipole on one end and some kind of stealthy one on the other. I assume this would have to be ground wave only given the distance and current band conditions. My parents are both techs so we're currrently limited to parts of 10m as the lowest band and I'd like to have something reliable without need repeaters for disaster comms. We actually only have a few single hop VHF/UHF repeaters between us, though quite a few linked ones. I've also thought of 6m due to smaller antenna requirements, but I'm pretty sure this is too far... Thanks! 75 miles is do-able, but stretching it on 10m.. #1, if using simple antennas, good elevated verticals, or ground planes would be your only chance. No way you are likely to make it with horizontal dipoles. And to make 75 miles, the antennas really need to be fairly high. The hills may be a problem.. Power would help... If both stations had high ground planes, to talk 75 miles with any reliability, you really would need an amp, doing 500+ watts on both ends... There is no NVIS on 10m, unless you get the fluke chance of backscatter, or aurora.. I've done both on 10m... Backscatter is not that uncommon, but the aurora is not going to happen too often. But I've used aurora propogation to work stations a lot closer than usual.. Sounds like talking through a window fan... The last time I did that was in the late 80's at the solar cycle peak. Anyway, talking 75 miles reliably on 10 can be done, but most that do it run high verticals, or beams, and most run power. Note CBers.. They do it all the time. But again, that hill may or may not be a problem.. What you might want to look at is 2m SSB using beams.. But again, the hills... ?? Those will be more of a problem, the higher in freq you go I bet. Maybe it's time to upgrade, and use a freq more suited, like 40 in the day, and 75 at night.. Actually, 75m will work that distance most any time of the day. If you can't have at least a good vertical on 10m, it ain't gonna happen. Where as a low stealth dipole would work on the lower bands, using NVIS propo. Also, no power is needed in most cases.. 100w is more than enough. 10w is plenty in many cases. MK |
#6
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Joey wrote:
"My parents are both techs so we`re currently limited to parts of 10m as the lowest band and I`d like to have something available without needing repeaters for disaster comms." I`d like a million dollars too! 75 miles is reliably unlikely without a line of sight path between radios at VHF unless expensive techniques are used. A repeater located between the radios makes success much more likely. Examine the ARRL "Repeater Directory" and borrow a hand-held (likely for 2-meters) and see which repeaters you can call up from both ends of the path you would like to work. You will probably find you are in-business but not for profit as it is amateur radio. For back up in emergencies, you can use your cell phone or a wired phone. Best regards, Richard Harrison, KB5WZI |
#7
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Joey wrote:
Hi, I'm trying to determine if I could use 10 meters to contact a station about 75 miles away with about 2500ft elevation of a couple sets of hills in between with just simple antennas on either end. Perhaps a 10m dipole on one end and some kind of stealthy one on the other. I assume this would have to be ground wave only given the distance and current band conditions. My parents are both techs so we're currrently limited to parts of 10m as the lowest band and I'd like to have something reliable without need repeaters for disaster comms. We actually only have a few single hop VHF/UHF repeaters between us, though quite a few linked ones. I've also thought of 6m due to smaller antenna requirements, but I'm pretty sure this is too far... Thanks! 2m SSB or CW with modest power and antennas have a great chance of doing what you wish. A better description of the terrain would help. 2500 above mean average terrain? (I doubt that but have to ask) A couple of hills. Sharp ridges? Above the line of sight? Probably still quite doable. I used to work from Potsdam NY to Plattsburgh NY (and a good chunk of Vermont) virtually every evening on 144.200 with a 12 foot yagi at 25 feet on my end, a 17 foot on the other, using about 60 watts, and the Tug Hill Plateau and a couple small mountains in the way. 2m "weak signal" is an often overlooked mode for 60 to 150 miles that is very reliable for point to point. tom K0TAR |
#8
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Joey wrote:
Hi, I'm trying to determine if I could use 10 meters to contact a station about 75 miles away with about 2500ft elevation of a couple sets of hills in between with just simple antennas on either end. Perhaps a 10m dipole on one end and some kind of stealthy one on the other. I assume this would have to be ground wave only given the distance and current band conditions. My parents are both techs so we're currrently limited to parts of 10m as the lowest band and I'd like to have something reliable without need repeaters for disaster comms. We actually only have a few single hop VHF/UHF repeaters between us, though quite a few linked ones. I've also thought of 6m due to smaller antenna requirements, but I'm pretty sure this is too far... Thanks! Oh, 6 would work too, but 2 is easier and the antennas smaller yet. tom K0TAR |
#9
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Joey wrote in news:dd64339h0kluu9d5kqu0tff6h9r6nmpbdl@
4ax.com: Hi, I'm trying to determine if I could use 10 meters to contact a station about 75 miles away with about 2500ft elevation of a couple sets of hills in between with just simple antennas on either end. Perhaps a 10m dipole on one end and some kind of stealthy one on the other. I assume this would have to be ground wave only given the distance and current band conditions. My parents are both techs so we're currrently limited to parts of 10m as the lowest band and I'd like to have something reliable without need repeaters for disaster comms. We actually only have a few single hop VHF/UHF repeaters between us, though quite a few linked ones. I've also thought of 6m due to smaller antenna requirements, but I'm pretty sure this is too far... Thanks! Joey, You have given a lot of information, and yet too little. The distance you nominate can be a challenge, yet routinely possible on frequencies from 28MHz to 440MHz, depending.... My thoughts are that simplex contacts will be unlikely without effective outside antennas, though not necessarily directional antennas, but they would help. You note you may have access to several repeaters, than can certainly equalise bad locations or impossible paths (eg granite), but then you might not want to conduct family chat on repeaters (though that is they way they seem to have gone here since many of our new six hour hams with their shack on their belt seem to be family members). An FM repeater in a very good location may support contacts reliably out to 150+km for each station, depending... Another possibility might be using IRLP build a path. To give you an example, I can work the 2m repeater at Mt Ginini (exceptional site) from the car on my driveway here at Narooma, 155km (~ 95mi) over mountains etc (but we don't have real mountains here do we?), it would be easier with a 5dB gain omni on the house. I could use a handheld to make the trip to a repeater 90km (~56mi) away and use IRLP to anywhere in the world (if I liked IRLP). Then by contrast, there would be places where you couldn't work a repeater 10km away with a handheld. So, it may be that a path via a VHF or UHF repeater might be more viable than 10m. Perhaps some experimentation is in order, that is what ham radio was about once. Owen |
#10
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Joey wrote:
Hi, I'm trying to determine if I could use 10 meters to contact a station about 75 miles away with about 2500ft elevation of a couple sets of hills in between with just simple antennas on either end. Perhaps a 10m dipole on one end and some kind of stealthy one on the other. I assume this would have to be ground wave only given the distance and current band conditions. My parents are both techs so we're currrently limited to parts of 10m as the lowest band and I'd like to have something reliable without need repeaters for disaster comms. We actually only have a few single hop VHF/UHF repeaters between us, though quite a few linked ones. I've also thought of 6m due to smaller antenna requirements, but I'm pretty sure this is too far... Thanks! Just off-hand, I would suspect for reliable and consistent communications a three element yagi and ~100 watts on each end would result in enjoyable rag chews ... same for 6m. Height? More the better. Seventy-five miles on omni antennas is very chancy, in my humble opinion. But then, power/height would be the main variables, enough height and power would certainly help. Regards, JS |
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