User Panel
User Panel
User Panel
|
Posted: 2/28/2015 12:57:11 AM EDT
Me and my buddy were trying to see if there was any way for us to make contact without using a repeater. We're both techs at the moment. Distance is 23.9 miles, but as you'll see, he's in a hole.Any realistic way for us to make contact?
ETA: that hill is 100' higher than him.. |
|
|
|
Posted: 2/28/2015 1:23:43 AM EDT
[#1]
Satellites.
|
|
|
|
Posted: 2/28/2015 1:37:35 AM EDT
[#2]
Have a friend in Arizona who had a similar problem.
After some experimentation, they discovered that using 6 meters was the only reliable solution for them. Some form of knife edge propagation made their comms bomb proof. If you both have HF rigs, I'd try both 6 and 10 meters. If you're using HTs, a better antenna might help. I've managed a bit over 120 miles with a Yeasu FT-60 and a mag mount antenna, but I suspect the stars were aligned for that one! Cheers... Jim |
|
|
|
Posted: 2/28/2015 8:54:08 AM EDT
[#3]
Quote HistoryQuoted:
Have a friend in Arizona who had a similar problem. After some experimentation, they discovered that using 6 meters was the only reliable solution for them. Some form of knife edge propagation made their comms bomb proof. If you both have HF rigs, I'd try both 6 and 10 meters. If you're using HTs, a better antenna might help. I've managed a bit over 120 miles with a Yeasu FT-60 and a mag mount antenna, but I suspect the stars were aligned for that one! Cheers... Jim With VHF, he would need a 100' tower, or close to 100', depending on your antenna height to clear that hill. 10m with NVIS antennas. This may work. Bill |
|
|
|
Posted: 2/28/2015 9:12:09 AM EDT
[#4]
I'd try 10m since you are both stuck with that right now (locally there is a 10m net every evening, most guys running verticals). 10m radios are pretty cheap (older Radio Shack rigs about $50) and antenna are easy to build.
A General Up-Grade will net you a great deal more room to play. 80m NVIS would more than likely do it. I've done 80m as close as 12 miles (groundwave) and all over SC/NC 50+/- miles with a random wire about 8' above ground. ETA: Sorry, those acronyms and hamspeak is just so easy... NVIS1 NVIS2 Random Wire1 Random Wire 2 Groundwave-random Youtube search 10m Dipole 10m Dipole from ARRL and if you haven't heard, I podcast for guys just like Y'all: right here |
|
|
|
Posted: 2/28/2015 10:21:15 AM EDT
[#5]
CW on 80m should do the trick (Techs have CW privileges on 80m from 3.525-3.600 MHz). You would want a low horizontal antenna (loop or dipole) on each end.
ETA: Did the software that generated that diagram give you an estimated path loss? |
|
|
|
Posted: 2/28/2015 10:35:08 AM EDT
[#6]
Have you actually tried it? There may be another path that isn't blocked as depicted in your cross section.
|
|
|
|
Posted: 2/28/2015 11:02:19 AM EDT
[#7]
Use a Yagi and point it at the crest of the hill? Sharp-line diffraction? Just a really WAG.
Diffraction |
|
|
|
Posted: 2/28/2015 11:05:45 AM EDT
[#8]
Quote HistoryQuoted:
A General Up-Grade will net you a great deal more room to play. 80m NVIS would more than likely do it. I've done 80m as close as 12 miles (groundwave) and all over SC/NC 50+/- miles with a random wire about 8' above ground. I'm not much for random wires, as they randomly work or not, depending on specific length (really!), but yes on NVIS, 80 m or 40 m. NVIS is a signal nearly straight up (Near Vertical) bounces off the ionosphere, and comes down nearby (Incident Skywave) like pointing a water hose straight up and wetting down everyone nearby. This is done on the lower HF bands, 80, 60, 40 meters, by using a dipole, OCFD, or other horizontal wire antenna close to the ground, 6' to 10'. This aims the signal up, much like having a mirror behind a candle. I've seen HF contacts in as close as 5-30 miles done like this, an 80 m dipole 6' off the ground. Remember the old Army movies with the long whip antenna bent over and tied off to the front bumper? Yes, that was to clear tree limbs, but it also gave solid NVIS operation. So... go get that General ticket! |
|
|
|
Posted: 2/28/2015 11:38:04 AM EDT
[#9]
Quote HistoryQuoted:
10m with NVIS antennas. This may work. NVIS is impossible on 10 meters. If you have access to the top of that 100 foot hill, one option you might explore is a passive repeater. High gain yagi pointed at one station connected via a short jumper to another high gain yagi pointed at the other station. Antenna gain vs size considerations make higher frequencies more realistic for a passive repeater. But as previously mentioned, first step is to actually try the path preferably on various bands. Some variety of knife edge diffraction or reflective paths might make it happen, and those effects vary with frequency so need to try the different bands. If you try directional antennas, realize that the signal path may well not be the most direct path between the two locations. |
|
|
|
Posted: 2/28/2015 11:41:54 AM EDT
[#10]
In order of what i think will work-
10m SSB at 100W 6m FM at 100W with a beam |
|
|
|
Posted: 2/28/2015 12:09:45 PM EDT
[#11]
Get out there and start experimenting, signals can bounce off things too along with knife edge propagation. Both of you using something like my home made Yagi might help figuring it out too. If you can get it to work then get better antennas and use radios with more watts.
|
|
|
|
Posted: 2/28/2015 12:27:37 PM EDT
[#12]
One other thing that might work if you have the capabilities- 2m SSB with directional antennas.
But I'm willing to bet that 6m fm at 100w will do it. Back when the highway patrol and most police ran low-band VHF in that range the coverage for that kind of terrain on simplex was usually pretty good. You could get some old surplus low band public safety radios and put them on 6M or 10m fm at 110w. |
|
|
|
Posted: 2/28/2015 2:46:42 PM EDT
[#13]
Quote HistoryQuoted:
One other thing that might work if you have the capabilities- 2m SSB with directional antennas. But I'm willing to bet that 6m fm at 100w will do it. Back when the highway patrol and most police ran low-band VHF in that range the coverage for that kind of terrain on simplex was usually pretty good. You could get some old surplus low band public safety radios and put them on 6M or 10m fm at 110w. Techs don't get access to the FM portion of 10m. |
|
|
|
Posted: 2/28/2015 3:22:52 PM EDT
[#14]
Quote HistoryQuoted:
Techs don't get access to the FM portion of 10m. Quote HistoryQuoted:
Quoted:
One other thing that might work if you have the capabilities- 2m SSB with directional antennas. But I'm willing to bet that 6m fm at 100w will do it. Back when the highway patrol and most police ran low-band VHF in that range the coverage for that kind of terrain on simplex was usually pretty good. You could get some old surplus low band public safety radios and put them on 6M or 10m fm at 110w. Techs don't get access to the FM portion of 10m. Ahh that's right. 10m SSB in theory will go do better, but if he wants something to use regularly he probably wants a squelch to leave it on all the time listening, and FM works a lot nicer. |
|
|
|
Posted: 2/28/2015 3:58:01 PM EDT
[#15]
Quote HistoryQuoted:
Get out there and start experimenting, signals can bounce off things too along with knife edge propagation. Both of you using something like my home made Yagi might help figuring it out too. If you can get it to work then get better antennas and use radios with more watts. http://i228.photobucket.com/albums/ee73/tangotag_bucket/8168192C-694F-402B-9B30-DBE3E9D76597_zpscmmehuir.jpg I have been wanting to make that antenna for a long time. Off to the garage to start scavenging..... |
|
|
|
Posted: 2/28/2015 4:13:48 PM EDT
[#16]
Quote HistoryQuoted:
With VHF, he would need a 100' tower, or close to 100', depending on your antenna height to clear that hill. 10m with NVIS antennas. This may work. Bill Quote HistoryQuoted:
Quoted:
Have a friend in Arizona who had a similar problem. After some experimentation, they discovered that using 6 meters was the only reliable solution for them. Some form of knife edge propagation made their comms bomb proof. If you both have HF rigs, I'd try both 6 and 10 meters. If you're using HTs, a better antenna might help. I've managed a bit over 120 miles with a Yeasu FT-60 and a mag mount antenna, but I suspect the stars were aligned for that one! Cheers... Jim With VHF, he would need a 100' tower, or close to 100', depending on your antenna height to clear that hill. 10m with NVIS antennas. This may work. Bill The reality of NVIS is the only real reliable NVIS frequency is 5 mhz and lower. And anything NVIS above 7mhz just does not exist. Short skip can and does happen, but it is very rare at 28 mhz, and usually through E-Skip propagation. At 23 miles it is all going to be ground wave propagation, or LOS. |
|
|
|
Posted: 2/28/2015 4:55:21 PM EDT
[#17]
What have you tried so far? Obviously, 25 miles is too far if both of you use a hand-held 5W radio with a small antenna, even on a flat ground. Have you tried running 50 Watts with directional antennas?
You signal may partially refract or reflect off some buildings, hills. etc. Also raising antennas 30-40 ft. may help tremendously. IMHO, your best choice is to upgrade to General and take advantage of NVIS, like mentioned previously. NVIS may work on 40m band but your best bet is the 80M band. 60 meters may work too but it's always too crowded. I routinely talk to stations 25-50 miles away on 80 meters, even with my small Tarheel mobile antenna and a 100W radio. Cut your antenna to resonate on 3.820 Mhz. Anything above that is way to crowded at night. It's best to have an Extra ticket and stay below 3.800 Mhz. |
|
|
|
Posted: 2/28/2015 5:04:20 PM EDT
[#18]
First, have you tried to make contact? Using something like a full-power (e.g. 50W) 2M FM radio with a passable rooftop antenna?
A 100' hill is not that big, and contrary to popular belief the typical VHF propagation mode usually isn't line of sight, but some mix of line of sight, edge diffraction, and scatter. If that doesn't work, I'd probably try the same thing on 6M and 70cm if radios are available. If that still doesn't work, then, staying within tech privledges, I'd try SSB on 2M and 70cm with normal antennas, and if that didn't work, move to a decent gain (10dB) yagi. That will work. Troposcatter is a real thing. |
|
|
|
Posted: 2/28/2015 5:17:44 PM EDT
[#19]
Quote HistoryQuoted:
First, have you tried to make contact? Using something like a full-power (e.g. 50W) 2M FM radio with a passable rooftop antenna? A 100' hill is not that big, and contrary to popular belief the typical VHF propagation mode usually isn't line of sight, but some mix of line of sight, edge diffraction, and scatter. If that doesn't work, I'd probably try the same thing on 6M and 70cm if radios are available. If that still doesn't work, then, staying within tech privledges, I'd try SSB on 2M and 70cm with normal antennas, and if that didn't work, move to a decent gain (10dB) yagi. That will work. Troposcatter is a real thing. There is truth there, the best thing to do is try it. |
|
|
|
Posted: 2/28/2015 8:33:45 PM EDT
[#20]
Hide 2 back-to-back yagis on the hilltop.
Posted Via AR15.Com Mobile |
|
|
|
Posted: 2/28/2015 8:50:23 PM EDT
[#21]
Quote HistoryQuoted:
Hide 2 back-to-back yagis on the hilltop. Posted Via AR15.Com Mobile This may work too! But like Gamma and seek2 said, line-of-sight isn't all it's cracked up to be. 
I'd try the 10el Yagi and 50W on both ends first, then maybe try the passive antennas like quoted above. |
|
|
|
Posted: 2/28/2015 9:13:02 PM EDT
[#22]
Or try using something like Olivia
|
|
|
|
Posted: 2/28/2015 10:18:59 PM EDT
[#23]
Quote HistoryQuoted: After some experimentation, they discovered that using 6 meters was the only reliable solution for them. Some form of knife edge propagation made their comms bomb proof. If you both have HF rigs, I'd try both 6 and 10 meters. Antennas. Go beam of some kind. Say you get a yagi with a gain of 6db. Feed the 50w from a run of the mill VHF mobile into that and you have an ERP of 200w compared to a dipole in the direction the beam is pointing. More importantly is that the beam receives signals better than a dipole in the direction the beam is pointing while rejecting signals off to the sides and rear. Here I participate in a weekly 2m simplex net. Net control is 32 miles away. His antenna is on a 100ft tower. Due to HOA restrictions all my stuff is in the attic. In some ways my net control is like your op on the left of your graphic and I'm the guy in the hole. Slam dunk comms 100% of the time. Experiment and let us know what works. Check my math on the ERP calc please. I just got off a 14 hour day and the brain is toast. |
|
|
|
Posted: 2/28/2015 11:01:23 PM EDT
[#24]
What made that plot?
|
|
|
|
Posted: 2/28/2015 11:06:01 PM EDT
[#25]
Cell phone
I believe meteor scatter and moon bounce work at VHF. Are there any passes in the hills, not in a straight line between the stations, that would allow the signal to be reflected off another hill or building? Quoted:
What made that plot? Yeah that's pretty sexy! 
|
|
|
|
Posted: 2/28/2015 11:49:30 PM EDT
[#26]
Quote HistoryQuoted: Get out there and start experimenting, signals can bounce off things too along with knife edge propagation. Both of you using something like my home made Yagi might help figuring it out too. If you can get it to work then get better antennas and use radios with more watts. http://i228.photobucket.com/albums/ee73/tangotag_bucket/8168192C-694F-402B-9B30-DBE3E9D76597_zpscmmehuir.jpg Is the coax choke necessary? I built one of those without it and the SWR and impedance look ok on the analyser after tweaking the driven element length and messing around with the shape of the hairpin match. |
|
|
|
Posted: 3/1/2015 12:42:44 AM EDT
[#27]
Quote HistoryQuoted:
Is the coax choke necessary? I built one of those without it and the SWR and impedance look ok on the analyser after tweaking the driven element length and messing around with the shape of the hairpin match. Quote HistoryQuoted:
Quoted:
Get out there and start experimenting, signals can bounce off things too along with knife edge propagation. Both of you using something like my home made Yagi might help figuring it out too. If you can get it to work then get better antennas and use radios with more watts. http://i228.photobucket.com/albums/ee73/tangotag_bucket/8168192C-694F-402B-9B30-DBE3E9D76597_zpscmmehuir.jpg Is the coax choke necessary? I built one of those without it and the SWR and impedance look ok on the analyser after tweaking the driven element length and messing around with the shape of the hairpin match. I never tested it on a meter. It was a group project for our ARES/RACES group. We built about twenty all using the same plans, which said to add the coil choke if the antenna would be used for Tx and not just for receiving. Our antennas get regularly used for fox hunts. Personally, I've used it to check into nets held on repeaters beyond my normal HT range. I have also used it for simplex with HTs mine using the Yagi and a friend using a High-Gain on his HT where the distance was too great for both radios with just using High-Gain antennas. We coordinated the call using cell phones initially, his report was with the Yagi the audio was crystal clear where he couldn't even hear me with the squelch open and me using the High-Gain antenna. I'm completely sold on hand held Yagis. |
|
|
|
Posted: 3/1/2015 2:16:56 AM EDT
[#28]
Quoted:
Me and my buddy were trying to see if there was any way for us to make contact without using a repeater. We're both techs at the moment. Distance is 23.9 miles, but as you'll see, he's in a hole.Any realistic way for us to make contact? http://oi57.tinypic.com/2qmnju1.jpg ETA: that hill is 100' higher than him.. What's the distance to the hill from each house? A passive repeater may be a good alternative but in the scheme of things, passive repeaters are extremely lossy. You essentially sum the path loss of point a to the passive repeater and then point b to the passive repeater. Then you can calculate wether or not it will be a strong enough signal to use. It's a much greater loss (usually close to 2x plus line loss in the jumper) compared to a direct LOS hop. Another question, did your propagation program tell you by how much height you need in order to clear the 60% of the first fresnel zone? A |
|
|
|
Posted: 3/1/2015 8:23:11 PM EDT
[#29]
Quote HistoryQuoted: With VHF, he would need a 100' tower, or close to 100', depending on your antenna height to clear that hill. 10m with NVIS antennas. This may work. Bill Quote HistoryQuoted: Quoted: Have a friend in Arizona who had a similar problem. After some experimentation, they discovered that using 6 meters was the only reliable solution for them. Some form of knife edge propagation made their comms bomb proof. If you both have HF rigs, I'd try both 6 and 10 meters. If you're using HTs, a better antenna might help. I've managed a bit over 120 miles with a Yeasu FT-60 and a mag mount antenna, but I suspect the stars were aligned for that one! Cheers... Jim With VHF, he would need a 100' tower, or close to 100', depending on your antenna height to clear that hill. 10m with NVIS antennas. This may work. Bill I didn't think NVIS reflections started until about the 40m-80m bands...?? |
|
|
|
Posted: 3/1/2015 8:31:30 PM EDT
[#30]
Quote HistoryQuoted:
I didn't think NVIS reflections started until about the 40m-80m bands...?? Quote HistoryQuoted:
Quoted:
Quoted:
Have a friend in Arizona who had a similar problem. After some experimentation, they discovered that using 6 meters was the only reliable solution for them. Some form of knife edge propagation made their comms bomb proof. If you both have HF rigs, I'd try both 6 and 10 meters. If you're using HTs, a better antenna might help. I've managed a bit over 120 miles with a Yeasu FT-60 and a mag mount antenna, but I suspect the stars were aligned for that one! Cheers... Jim With VHF, he would need a 100' tower, or close to 100', depending on your antenna height to clear that hill. 10m with NVIS antennas. This may work. Bill I didn't think NVIS reflections started until about the 40m-80m bands...?? They don't |
|
|
|
Posted: 3/1/2015 11:32:20 PM EDT
[#31]
Quote HistoryQuoted: I never tested it on a meter. It was a group project for our ARES/RACES group. We built about twenty all using the same plans, which said to add the coil choke if the antenna would be used for Tx and not just for receiving. Our antennas get regularly used for fox hunts. Personally, I've used it to check into nets held on repeaters beyond my normal HT range. I have also used it for simplex with HTs mine using the Yagi and a friend using a High-Gain on his HT where the distance was too great for both radios with just using High-Gain antennas. We coordinated the call using cell phones initially, his report was with the Yagi the audio was crystal clear where he couldn't even hear me with the squelch open and me using the High-Gain antenna. I'm completely sold on hand held Yagis. Quote HistoryQuoted: Quoted: Quoted: Get out there and start experimenting, signals can bounce off things too along with knife edge propagation. Both of you using something like my home made Yagi might help figuring it out too. If you can get it to work then get better antennas and use radios with more watts. http://i228.photobucket.com/albums/ee73/tangotag_bucket/8168192C-694F-402B-9B30-DBE3E9D76597_zpscmmehuir.jpg Is the coax choke necessary? I built one of those without it and the SWR and impedance look ok on the analyser after tweaking the driven element length and messing around with the shape of the hairpin match. I never tested it on a meter. It was a group project for our ARES/RACES group. We built about twenty all using the same plans, which said to add the coil choke if the antenna would be used for Tx and not just for receiving. Our antennas get regularly used for fox hunts. Personally, I've used it to check into nets held on repeaters beyond my normal HT range. I have also used it for simplex with HTs mine using the Yagi and a friend using a High-Gain on his HT where the distance was too great for both radios with just using High-Gain antennas. We coordinated the call using cell phones initially, his report was with the Yagi the audio was crystal clear where he couldn't even hear me with the squelch open and me using the High-Gain antenna. I'm completely sold on hand held Yagis. I did some googling around after I posted and I guess the choke is to keep RF off of the feedline since it is right in the midst of the antenna elements. Which would make sense why it is recommended for antennas that will be used to transmit. I have mine mounted on a tripod and was experimenting with APRS today. (Which is a great way to get a signal report without bothering other hams too much or taking up a lot of time on the air). I turned the antenna away from a known digipeater and sure enough, it didn't send back my packet, where it does when the antenna is aimed at it. I guess the antenna really is pretty directional. :D |
|
|
|
Posted: 3/2/2015 4:23:00 PM EDT
[#32]
Sorry to just get back. So far we just tried HTs with stock rubber duckys. I have one of the roll up slimjim antennas i was going to hoist off the ground a ways and try but havent yet due to the cold/rainy/snowy weather thats been going on. I wanted to get some advice before i just started throwing money at different radios/antennas. I plan on making that tape measure yagi as i have everything needed except for the coax, so we will both have one of those to try.
The program i used is Radio Mobile, i used the online version, but there is one you can download too. Seems like a pretty good program, especially for somebody who knows what theyre doing
The guy who posted satellites now has me looking into making contact with SO-50 .
But thanks for all the suggestions and like has been said, we really need to start trying stuff. We are going to try with 2m first, and then move on to something else if need be. Feel free to keep the suggestions coming, im trying to soak up all the knowledge i can. |
|
|
|
Posted: 3/2/2015 4:46:24 PM EDT
[#33]
Quote HistoryQuoted:
The program i used is Radio Mobile, i used the online version, but there is one you can download too. Seems like a pretty good program, especially for somebody who knows what theyre doing Did it give you an estimated path loss? |
|
|
|
Posted: 3/2/2015 6:26:37 PM EDT
[#34]
Quote HistoryQuoted:
Sorry to just get back. So far we just tried HTs with stock rubber duckys. I have one of the roll up slimjim antennas i was going to hoist off the ground a ways and try but havent yet due to the cold/rainy/snowy weather thats been going on. I wanted to get some advice before i just started throwing money at different radios/antennas. I plan on making that tape measure yagi as i have everything needed except for the coax, so we will both have one of those to try. The program i used is Radio Mobile, i used the online version, but there is one you can download too. Seems like a pretty good program, especially for somebody who knows what theyre doing
The guy who posted satellites now has me looking into making contact with SO-50 .
But thanks for all the suggestions and like has been said, we really need to start trying stuff. We are going to try with 2m first, and then move on to something else if need be. Feel free to keep the suggestions coming, im trying to soak up all the knowledge i can. OK, you really need to use something with significantly more power than an HT. HTs will work for true line of sight, and will give passable results on flat-ish terrain from 2 to maybe 10 miles tops, but they're not going to work for this unless you can actually eyeball each other. If money is tight I'd suggest either a couple used 2M mobiles or two new Kenwood TM-281s or Yaesu FT-1900s. |
|
|
|
Posted: 3/2/2015 8:01:01 PM EDT
[#35]
Quote HistoryQuoted:
Sorry to just get back. So far we just tried HTs with stock rubber duckys. I have one of the roll up slimjim antennas i was going to hoist off the ground a ways and try but havent yet due to the cold/rainy/snowy weather thats been going on. I wanted to get some advice before i just started throwing money at different radios/antennas. I plan on making that tape measure yagi as i have everything needed except for the coax, so we will both have one of those to try. The program i used is Radio Mobile, i used the online version, but there is one you can download too. Seems like a pretty good program, especially for somebody who knows what theyre doing
The guy who posted satellites now has me looking into making contact with SO-50 .
But thanks for all the suggestions and like has been said, we really need to start trying stuff. We are going to try with 2m first, and then move on to something else if need be. Feel free to keep the suggestions coming, im trying to soak up all the knowledge i can. I'm also tempted to build a yagi and try for some HT satellite contacts. But that'll be it's own build thread. |
|
|
|
Posted: 3/2/2015 8:21:23 PM EDT
[#36]
2m kilowatt amplifier.......I'm just saying.
|
|
|
|
Posted: 3/2/2015 10:21:41 PM EDT
[#37]
Quote HistoryThat and a couple longboom yagis will get you moonbounce. However our OP distance is a bit less aggressive.
5w HTs are not going to do what you want to do. No matter the antenna. I'm still sticking with 50w mobiles as base rigs such as the FT-1900 coupled with a compact yagi or log periodic will net you the results. At a minimum start with the 50w rig and give it a try with a good vertical such as the Diamond X50. If no-go then give the gain antennas a try. |
|
|
Win a FREE Membership!
Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!
You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.
AR15.COM is the world's largest firearm community and is a gathering place for firearm enthusiasts of all types.
From hunters and military members, to competition shooters and general firearm enthusiasts, we welcome anyone who values and respects the way of the firearm.
Subscribe to our monthly Newsletter to receive firearm news, product discounts from your favorite Industry Partners, and more.
Copyright © 1996-2024 AR15.COM LLC. All Rights Reserved.
Any use of this content without express written consent is prohibited.
AR15.Com reserves the right to overwrite or replace any affiliate, commercial, or monetizable links, posted by users, with our own.
