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Old 11-20-2010, 5:44 PM
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Default Band / Distance Question

Just curious, if a band exists that would allow simplex on distances up to 20/30 miles? I'm just studying for my exam now and hope to be licensed end of year or early next year. A few friends and myself are hoping to get into it. We were at first planning on only looking at the 2m band however an additional person has showed interest and they are quit a while out.
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Old 11-20-2010, 5:59 PM
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With suitable antennas, 2m simplex at 20-30 miles is quite doable.
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Old 11-20-2010, 6:12 PM
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VHF/UHF is a line-of-sight area. If there are large obstructions in the way (hills/mountains/etc.) the usable range is reduced. The best -simple- solution to that sort of thing is a taller antenna. If the two antennas can 'see' each other, no reason why you can't talk to them. There are limits to that though.
The HF bands can 'see' over the horizon when VHF/UHF can't. That's before signals start bouncing off of the various layers of the ionosphere. The lower you go in frequency, the more 'further' over the horizon the radio can 'see'. (And if that isn't a simplification, I don't know what is!) And the 'catch' to all of it is that "Momma Nature" controls the whole thing with 'her' propagation. Some days you'll do good to get across the street, if 'she's in one of 'her' moods.
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Old 11-20-2010, 6:28 PM
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Quote:
Originally Posted by W9RXR View Post
With suitable antennas, 2m simplex at 20-30 miles is quite doable.
Cool!
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Old 11-20-2010, 6:30 PM
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Originally Posted by LtDoc View Post
VHF/UHF is a line-of-sight area. If there are large obstructions in the way (hills/mountains/etc.) the usable range is reduced. The best -simple- solution to that sort of thing is a taller antenna. If the two antennas can 'see' each other, no reason why you can't talk to them. There are limits to that though.
The HF bands can 'see' over the horizon when VHF/UHF can't. That's before signals start bouncing off of the various layers of the ionosphere. The lower you go in frequency, the more 'further' over the horizon the radio can 'see'. (And if that isn't a simplification, I don't know what is!) And the 'catch' to all of it is that "Momma Nature" controls the whole thing with 'her' propagation. Some days you'll do good to get across the street, if 'she's in one of 'her' moods.
Have fun.
- 'Doc
So what might you recommend for a band to use? You mentioned HF can give you much longer distance than VHF and UHF, what bands exist within the HF frequency?

Sorry for the noob questions
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Old 11-20-2010, 6:45 PM
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HF radio propagation is complex.
You pick HF bands depending on:
Where the stations are located
Distance between stations
Time of day
Time of the year
Solar activity levels

http://www.google.com/search?q=HF+propagation

The frequencies you are allowed to use depends on your license class.
Canada and US HF ham band charts:
Canadian Amateur Radio Bands
http://www.arrl.org/files/file/Hambands_color.pdf
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Last edited by nd5y; 11-20-2010 at 6:47 PM..
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Old 11-20-2010, 8:37 PM
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I was looking at Halifax on Google Earth, looks like it would be very forgiving with VHF or UHF, and 30 miles should not be a problem. Max power (55 watts +) would probably get all of you guys a pretty good signal though. So in my opinion, your just wanting to talk to Bill and Joe (examples) across the city, correct? But if Joe lives 30 miles north of you, and Bill lives 30 south, you will have some problems, Bill and Joe may not be able to talk to each other. Out of curiosity, why couldn't you use a repeater? I would definatley go with 144 (2m), or 440 (70cm). That should definatley get the job done. You will need good antennas, mobile probably won't work simplex, but a good vertical antenna with about 3dbi or more of gain will do the job for a base station, and getting it up on a pole on your roof.

Depending on how far out the other person is, they may want to get a yagi and beam towards you and your friend, but that shouldn't be required. He will want to have a good antenna though with a higher gain.

These antennas, radios should do quite a good job:
Diamond F22A Antenna
Hustler G3-144 Vertical Antenna

Yaesu FT-1900R, Yaesu FT1900R Mobile Transceiver
Yaesu FT-2900R, Yaesu FT2900R Mobile Transceiver

Or, you and your friends may want to have a dual band radio, 2 meter, 70 centimeters, and do whatever is less congested, or better suits. Below are some dual band radios, and some dual band antennas.

Yaesu FT-7900R, Yaesu FT7900 Amateur Transceiver
Yaesu FTM-10R FT-M10SR FTM10 Amateur Transceiver

Hustler G6-270R g6270r Antenna
Comet GP1 Vertical Antenna
Diamond X200A Antenna
Diamond X50A Antenna

The person farthest out of town will want to have the best antenna, but that should give you a overall good setup for simplex. Make sure to get some low-loss feedline, and a power supply too!
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Old 11-20-2010, 10:05 PM
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Just about any amateur band is capable of 20-30 miles out, but 2m or 70cm would work just fine. Keep in mind, though, that propagation is highly variable, and blanket statements that say VHF/UHF is line of site are patently false. I've worked almost 1000 miles on 10 GHz, for example.

Relatively modest stations with outside antennas and no big rocks in the middle should have no problem working 30 miles on VHF or UHF.
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Old 11-21-2010, 1:38 AM
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If you go the 2m route, and want reliable simplex communications. On the new Ham radio market I'd personally limit your options to the FT2900 (75watts), IC-V8000 (75 watts), and the Kenwood TM-271 (65watts); on the basis they all offer more than 50watts maximum power output, which is a good starting point. You could also look into some used 100w Motorola VHF mobile radios and program in a few simplex frequencies, but if you're primarily looking at simplex you'll want the flexibility to move around frequencies with ease so that if you come across another conversation on your usual spot you'll have the ability to find a frequency not in use. Power to distance in VHF/UHF applications is an exponential relationship, and twice the power of a 40w mobile won't mean twice the range, but twice the power coupled with a good antenna system may make the difference of those last few miles needed to reach your buddies homes.

You'll also need to select your antennas carefully looking at the map considering if you're going to be in a line or spread out, an antenna offering a little more gain as Caleb mentioned, then you'll be increasing your ERP as well as your ability to pull in signals.

Higher above the ground is better but if you don't choose all the elements of your setup properly it may do more harm than good, look at the feedline and what the loss in dB is going to be over your given distance. You'll also need to consider anything you add in line (meters, lightening arrestors, etc.) and what loss it has. All of it boils down to the more of your signal that makes it to the antenna the more that antenna is going to be able to do with it. (On a side note that reminds me, invest in an SWR meter, start with the lowest power setting and make sure your SWR levels are low, even if it's advertised as ok, it's always a good idea to check SWR when modifying anything in the feedline, 10sec is cheaper than replacing a radio because something is amiss)

Also if you're selecting a higher wattage radio, when looking at your power supplies you'll need to know the Amperage draw of the radio, it's alot harder to find a power supply that'll handle 17-25 amps than it is to find one that'll handle ten or less, and my Ft2900 will draw 17amps when transmitting at full power. You'll also want to make sure you're 12v power supply puts out a true 13.8v not 12.0 or 12.1 or you may have some issues with it putting out less than the advertised power.

There's some equations you can look up if they're not already mentioned in your study materials that will help provide you a good theoretical guide so you should have some idea of what to expect, you can also find some software out there that will do the same and give you a map over your local terrain.

And something to keep in mind, while getting into radio with a few buddies is certainly a great way to learn things an get into it and stay active, however I'd encourage all of you to be sure not to limit yourselves to just that; there's a lot of ham radio out there that is available to you with a technician license, and even if it's just trying something one time, there is a lot of value to be had in the experience of attempting contacts via Satellite or the ISS, or building an antenna/power supply, checking into a net, trying out sideband, EME, CW, experimenting with APRS packet, developing fox hunt/radio direction finding skills (and with a group you can do a little triangulation too), in June get out on field day and have someone show you the added privilege of having a General or Extra License. Basically know what's out there and get a taste for it. Don't be afraid to branch out, it's a fun hobby; I'm constantly learning things, trying new things. It keeps my brain engaged and the hobby and my attitude toward it fresh.
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Old 11-21-2010, 6:40 AM
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Great information guys, thanks a lot! I guess this means our original dream of HT radios might have to be re-discussed... Regarding a related, person A lives across down, and indirectly between us are two 2m repeaters. Person B lives almost walking distance to me, so HT with no repeater would do us just fine. The challenge is person C, who lives almost 30mi out from all of us, and as far as we know there is no repeater between us.

Getting a good mobile might just be perfect, but more money for a noob than a HT lol. I have to figure out home mounting, car mounting, and everything else than.

One more question, a few of you guys mention the 70cm band, which is 440mhz I believe. If the lower the frequency means the longer the distance than wouldn't 2m be better than 70cm? Also, is 70cm not used mostly for emergency communications?
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Old 11-21-2010, 9:22 AM
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Quote:
Originally Posted by ObiHann View Post
Great information guys, thanks a lot! I guess this means our original dream of HT radios might have to be re-discussed... Regarding a related, person A lives across down, and indirectly between us are two 2m repeaters. Person B lives almost walking distance to me, so HT with no repeater would do us just fine. The challenge is person C, who lives almost 30mi out from all of us, and as far as we know there is no repeater between us.

Getting a good mobile might just be perfect, but more money for a noob than a HT lol. I have to figure out home mounting, car mounting, and everything else than.

One more question, a few of you guys mention the 70cm band, which is 440mhz I believe. If the lower the frequency means the longer the distance than wouldn't 2m be better than 70cm? Also, is 70cm not used mostly for emergency communications?
The person farthest out of town may want to get a beam for best reception, as one seen here: Elk Antennas, Elk Antenna 2M/440L5 Log Periodic

70cm is filled with quite a bit of ARES, and other emergency comms, but since it is a bigger band, don't worry. 70cm and 2 meter are mostly the same.
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Old 11-21-2010, 9:28 AM
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There are tons of publications available that will get you pretty well informed about this subject. The subject is/can be complicated and you'll never acquire the knowledge you really need unless you read up on the subject. If you're not already reading the books available from ARRL you might want to consider getting some of them. Look them up at American Radio Relay League | Ham Radio Association and Resources.
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Old 11-21-2010, 11:06 AM
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Quote:
Originally Posted by ObiHann View Post
One more question, a few of you guys mention the 70cm band, which is 440mhz I believe. If the lower the frequency means the longer the distance than wouldn't 2m be better than 70cm?
All things being equal (antenna gain, tx power out, etc.), free space loss is higher on 440 than on 2m. Absorption by trees and things is going to be higher, also. But not by a huge amount, and that can frequently be made up with antenna gain. For the distances you're talking about, the differences are insignificant.

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Also, is 70cm not used mostly for emergency communications?
The main operational difference between 2m and 440 is not emergency communications. There are some provisions in the rules that allow you to do things on 440 that can't be done on 2m, so you'll see some interesting things happening on repeaters, like remote base stations, more linking, and things like that.
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Old 11-21-2010, 11:22 AM
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Quote:
Originally Posted by ObiHann View Post
So what might you recommend for a band to use? You mentioned HF can give you much longer distance than VHF and UHF, what bands exist within the HF frequency?

Sorry for the noob questions
I recommend 70cm. since it has less "picket fencing" than vhf. Vhf has a characteristic that causes signals to drop in and out when you're on the fringe of line of sight.
But then vhf is not my favorite band,so I'm a bit biased!
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Old 11-21-2010, 12:45 PM
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I recommend 70cm. since it has less "picket fencing" than vhf. Vhf has a characteristic that causes signals to drop in and out when you're on the fringe of line of sight.
But then vhf is not my favorite band,so I'm a bit biased!
n9zas
I tend to have the same feelings as n9zas about 2 meter. So many old guys claim the 2m it the end all be all of ham radio.
I see it from a resource management point of view. 2m only have 4 mhz of bandwidth, and most of that is taken up with ssb, digital, and repeaters. The chance of ever putting up your own 2m repeater is highly unlikely.

440 has 30 mhz of band width.a good chunk for ATV, SSB, Digital, but still a nice area for repeaters and simplex. If you live in a rural area, you can probably put up your own repeater. So friends and I did some testing once. I was talking to a mobile 35 miles away simplex on 440, and when we switched to 2m, I couldnt even hear the station.
But during the same test, there was a station that I could hear on 2 meter, but not on 440. So when 2m doesnt work, 440 probably will, and vis versa. And dont forget about 6m FM. Some old low band 110w mobiles into a good ball mount quarter wave could do some wonders for local work, and then when the band opens up, you would be the first to know because youd already be using it!
Thats what we do locally.
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Old 11-21-2010, 5:04 PM
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The use of a repeater is certainly a possibility for you and your friends. You don't have to have a repeater -between- you, it can be almost anywhere. The qualifier on that is that all concerned can 'hit' that repeater, if you put a strong enough signal into it that it's understandable when retransmitted.
If you're close enough to a repeater, the typical 'rubberduck' antenna on most HT's will probably do just fine. An antenna better than that rubberduck makes things much easier as far as what you can hear and where you can be heard. (Almost anything is better than a rubberduck!) Power isn't all that important, but antenna height is. That's the biggest difference between repeaters and most other radios, the antenna height primarily, and the gain of the repeater's antenna, which will almost always be greater than the average hams fixed or mobile antenna. .
The differences between 2 meters and 70 cms are not going to be all that great, but they are there. If you have 70cm/440Mhz repeaters in your area, that's when it's nice to have a dual band radio. If there are no repeater on 70cm near you, a radio on that band isn't going to do you much good unless you use it for one of the other things you can, such as remote radio control, FSTV, etc. We have two 70cm repeaters here so a dual band radio was a good choice for me.
There's more to it, naturally, but that gives you a rough idea of the possibilities.
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(As for that 1000 mile range in the 'gigglehurtz' regions, if it isn't through satellite use, and if it's consistent, you'd better patent your set up! That is not typical at all. )
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Old 11-22-2010, 1:30 AM
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(As for that 1000 mile range in the 'gigglehurtz' regions, if it isn't through satellite use, and if it's consistent, you'd better patent your set up! That is not typical at all. )


You'd be surprised. It was via troposcatter, not satellite. It takes patience, perseverance, higher performance stations, and half decent conditions. But that sort of distance isn't at all THAT unusual on 10 GHz. California to Hawaii has been done on 5.6 GHz, and it's just a matter of time before it's done on 10 GHz. 500 mile contacts are routine during the contests. Beyond that, it takes considerably more effort.
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Old 11-22-2010, 5:26 PM
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You'd be surprised. It was via troposcatter, not satellite. It takes patience, perseverance, higher performance stations, and half decent conditions. But that sort of distance isn't at all THAT unusual on 10 GHz. California to Hawaii has been done on 5.6 GHz, and it's just a matter of time before it's done on 10 GHz. 500 mile contacts are routine during the contests. Beyond that, it takes considerably more effort.
What type of radio, transverter, and antenna are you using? I have really been wanting to get into the GHz's. Send me a PM if you can. Thanks!
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Old 11-22-2010, 8:56 PM
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What type of radio, transverter, and antenna are you using? I have really been wanting to get into the GHz's. Send me a PM if you can. Thanks!
Pm sent.
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Old 11-23-2010, 10:44 AM
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Let me be the first to tell you Master ObiHan Knewbie what the others have overlooked and made my gigglehertz. So, what about 10M? A Tech may operate in the old Novice sub band which gives the greatest range and you'll have fun working DX when the band opens which has been happening rather frequently here of late.
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