Posted: 5/11/2014 12:21:17 PM EDT
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Hello everyone! My needs are simply stated:
Mobile Unit to reach out to 300 miles, preferably 24v (so I can wire straight to my M109A3) Handheld unit that will work with many different types of other handhelds (marine, GMRS, etc.) I'm currently not HAM licensed but that will change in the near future. I don't mind putting a beat of a retractable antennae on the ole' Deuce either. |
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Well if you want to look at the car before you get your driver's license, to do 300 miles you will need to go HF radio. HF is typically not the entry level which tends to be licensed as a technician and normally get a VHF and or UHF radio and use lacal area repeaters. Which I can assure you not many repeaters in Army training areas. So to so what you want to do sounds more like going HF and using NVIS. Yaesu has been the most common field HF radio, toss up between a FT 857 and FT 897. They run off 12 -14 volts. You can figure how to tap in to 12v from one of the batteries off the 109's battery box. And to use HF frequencies, you will need to be a General class, which is not hard to do. In addition to that you will need to have your commander's ok. Can't help you there, but it's one of those best ask before you do thing. If it were hand held VHF radio I would say the opposite, as in ask for forgiveness.
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If you want anything to run on 24V you are looking at green radios. Definately not entry level, IMO.
300 miles... Yeah thats HF NVIS, which for milpacks = decent money. If you want VHF, you can find PRC-77's for not insane prices, along with the vehicle mount kits. But thats more like 3-5 miles not 300. Get a Ham general license first and then send me a PM. Radios are not cell-phones... lower your expectations... |
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Someone here on the board was building an M109 like you mention into a camper/BOV. They were also a ham (I think), and had installed a 'shack' in the rear of the truck.
If that is something like you are looking to do, I'd first (echo the above) get my licenses (General Class as a min) then install a voltage step down converter to allow use of all avail commercial amateur gear. 300 miles is easy with HF using NVIS (arf-links) To answer the purchasing ? from the OP, I'd buy these to start with: VHF/UHF Dual Band Mobile (Kenwood TM-V71a) HF Base/Mobile (Kenwood TS-480sat) That would basically cover all of your bases regarding local AO and further out. Further (or initial) Considerations would be a SSB CB, Mobile Scanner, Amateur Handhelds /Handhelds (b), and FRS/GMRS HT's I also wonder about a Cab to Bed intercom? ok, pipe dream over 
Spending $ on gear is fun, operating the gear is (fun'ner) rewarding and satisfying! The test are no big deal, we can help! |
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While simply stated, the requirements are anything but simple to accomplish.
A 300 mile range with no imtermediary infrastructure with anything resembling reliability = ham ticket for General or Extra class + NVIS. Even then 300 may be dicey due to conditions, antenna, etc. The laws of physics called. They said "Hollywood lies about radios every day." |
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Quoted:
While simply stated, the requirements are anything but simple to accomplish. A 300 mile range with no imtermediary infrastructure with anything resembling reliability = ham ticket for General or Extra class + NVIS. Even then 300 may be dicey due to conditions, antenna, etc. The laws of physics called. They said "Hollywood lies about radios every day." lmfao |
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If your ride is like the M809 series, the batteries are 12 volters connected series / parallel. You should be able to tap off one of the two series banks and get 12v but make sure you're on the one that's electrically closer to ground or your comms will be acting like a voltage divider, and that's bad juju.
Fuse both lines at the beginning of the run at the battery as well as after they pass through to the cab. Can't be too careful. |
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No one explained to the OP what NVIS is.
Jimmy, VHF (30 mhz - 300 mhz) (Very High Frequency), roughly, above the CB band on up past FM broadcast radio and lower TV channels, is all "line-of-sight". There's not much you can do about this with direct radio to radio operation except to get the antennas as high as possible to look over the horizon a bit. The antennas have to "see" each other. If past there, no amount of added power will help. UHF (300 mhz to 3 ghz) is on up past the wifi 2.4 ghz freq. Again, "line-of-sight". For your purposes, same as VHF. HF, on the other hand, 3-30 mhz (High Frequency), and we like to include the 160 m band (1.8-2.0 mhz, just above the AM broadcast band of 0.53-1.7 mhz) are the frequencies that can go past the horizon by reflecting off the ionosphere one or more times, and travel around the world, depending on time of day, season, sunspots, and other factors. An experienced ham can tell you which band will likely give the best results for a give time of day and distance. So... NVIS... where HF has a problem is talking in close. It is difficult at times, on some frequencies, to talk to someone 40 to 100 miles away, but you can easily skip past and talk to someone 150-500 miles away, for example. NVIS means Near Vertical Incident Skywave. What this means in real terms are a horizontal antenna close to the ground that will essentially beam almost straight up, and then reflect down nearby... like aiming a waterhose straight up and having it shower down all around you. That's why you used to see the WWII movies with the bumper mounted whip antenna bent over horizontally and tied to the front end. That makes the antenna horizontal and beam upwards. (And I'll bet many thought it was to keep the antenna from catching in foliage.) I participated in a special event station earlier this year in which the 40 meter (7.0-7.3 mhz) and 80 meter (3.5-4.0 mhz) antennas were dipoles only 5'-6' off the ground. They could talk as close in as 5 miles with ease. They also made contacts from 5 miles to 50 miles with ease. That is not easy with HF. Anyway, that's what NVIS is all about. |
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If I remember correctly, the M109's aren't setup like the M1008's and M1028's (24V under the hood, 12V in the cab). Only two ways I've ever seen it done is convert the entire deuce to 12V or run a DC-DC converter (I'm not sure where you find them) for vehicular application).
Question, do you plan on using HF while mobile? Nothing wrong if you do. Personally I find I spend too much time dicking around with the VFO knob (tuning knob) instead of herding a 6000 lb vehicle going 75 mph down the road. What I would suggest, a Kenwood TS-450 if you want to do the mobile HF transmitting or an Icom IC-718 if you plan on being stationary. (A Kaltronics KPC-3 with a 100W amp would be another suggestion) and a screw driver antenna. For VHF/UHF, I'd recommend a Kenwood TK-790 and a Kenwood TK-890. The reason I recommend those two radios for VHF/UHF radios...a) I'm fond of commercial radios and think they are superior to most VHF/UHF ham gear, b)the TK-x90 series of radios are unique in that they sport a single head/multiple radio function as well as a dual head/dual radio function that supports intercom between the two heads (designed for vehicles that don't have pass throughs between the cab and box). Yea it's probably a little more complex than what you need out of VHF/UHF but the commercial radios are literally idiot proof once programmed. |
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Whew...these things are hot!
24 to 12 50a little easier on the wallet bay choices |
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Unless the batteries are 24 volt, I see no need to use a converter. One of the batteries that are electrically closest to chassis ground will provide 12 volts at it's + terminal, and from there it's a simple matter to run your own wire to your equipment, expecially in a deuce, 5 ton, etc. Vehicle ground is vehicle ground.
A good HF rig will pull enough current that you wouldn't want to piggyback off any of the 12 volt wires (should they exist in the particular vehicle) anyway. |
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I like those ebay options. for $37 you can get a 25A output stepdown. The Kenwood mention upstream needs max 20.5A on transmit. Most other 100W rigs are in the same ballpark. So you could get one of these for each rig. Smaller ones for the dual-band U/V rig (only needs 13A max for the kenwood mentioned)
Spend a few bucks on some spares and you have a fairly robust solution. |
| NVIS is all about antenna setup. Basically you configure the antenna to send the transmitted wave almost straight up so it bounces back nearby instead of hundreds or thousands of miles away. Otherwise your signal will skip completely over your target recipient if they are within a few hundred miles depending on the frequency you are using. |
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Can anyone recommend a NVIS radio or is that an antenna set-up? I'll give you a real world example. I was working 20M from a mountain top using a small portable radio. A station just under 200 miles away wanted to work me, but my signal was skipping right over the top of him. Another Ham relayed that this station wanted to work me, and we switched to the 40M band and I dropped my antenna lower to the ground. Bam! We could hear each other just fine. The combo of a change in frequency and dropping my antenna lower made the radio waves bounce off the ground at a much higher angle, and come down at a shorter range. NVIS stands for Near Vertical Incidence Skywave. Skywave as in the signal bounces off the atmosphere. Near Vertical as in it goes almost straight up and almost straight down. Works like a charm. Just a little field experimentation with a buddy will quickly show you how to make it work. |
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Just about every army vehicle you've seen was configured for NVIS ops. That whip antenna isn't held down sideways for tree clearance, it's that way so it can fire RF straight up.
Most whip lengths that you can find to do this with will be non-resonant, so you'll need an antenna tuner to keep the mismatch that the radio sees to a minimum. |
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Quoted:
Just about every army vehicle you've seen was configured for NVIS ops. That whip antenna isn't held down sideways for tree clearance, it's that way so it can fire RF straight up. Most whip lengths that you can find to do this with will be non-resonant, so you'll need an antenna tuner to keep the mismatch that the radio sees to a minimum. Yeah pretty much this. Whips that are more horizontal than vertical work well enough for most NVIS stuff, alternately a in a fixed site a dipole set up lower to the ground (Like along a wooden fence) work pretty well too, or an V type wire antenna. You will likely need a good turner for most of those setups, 40m usually works well enough during the day at this point in the solar cylcle, and 80m at night. |
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You guys are giving me TONS information... Thank you! Can anyone recommend a NVIS radio or is that an antenna set-up? For NVIS you want low, horizontal antennas on 40, 60, 80 or even 160 meters (varies with sunspot activity and time of day). Here's a design for 40 and 80 meters that could be modified to incorporate 60 and/or 160 meters: 
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I'll assume you want to operate mobile - to keep it looking correct you'll want to take a peek over here
http://www.murphyjunk.net/ now.... I'm not suggesting go out and buy a military radio - it won't do anything you want it to but, if you pick a military antenna, in the correct freq range - it can be hooked to civilian radios - keep the look outside, better gear inside.. pic of truck!!!! (how has no one said this yet!) |
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No one explained to the OP what NVIS is. o rly? 
http://www.ar15.com/forums/t_10_22/604477_Ham_Radio_101.html&page=2#i10323358 ar-jedi |
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Quoted:
Hello everyone! My needs are simply stated: Mobile Unit to reach out to 300 miles, preferably 24v (so I can wire straight to my M109A3) Handheld unit that will work with many different types of other handhelds (marine, GMRS, etc.) I'm currently not HAM licensed but that will change in the near future. I don't mind putting a beat of a retractable antennae on the ole' Deuce either. this is a big ask. you need to break this into simple, manageable steps and work through them on by one. it's no different from restoring a surplus vehicle; not everything can be done in one evening, and you don't you even know what you don't know at the outset. moreover, the equipment alone will not do the job for you. there is learned technique as well. if i give a layperson an ar15, a shotgun, and a pistol -- and all quality representatives of each firearm -- and have them do a three-gun course, what happens? so, despite excellent equipment that individual was ineffective against the course. similarly, there is no "one stop shopping" in ham radio -- same as with firearms. you don't kill varmint with an accuracy international AWSM in .338 Lapua, and you don't try to take big game with a Ruger .22LR rifle. first, write down what you are trying to accomplish. the end goals. don't worry yet about HOW you are going to accomplish the list items, just write them down -- here, in this thread. e.g. -- communications from 0 to 300 miles. -- one setup for mobile operations. -- one setup for man-portable operations. -- high degree of interoperability with present standards. -- total cost not to exceed US$ N for each of these steps there will be issues, problems, budget constraints, etc which you will have to either overcome or forgo some aspects. then, a suggestion in terms of order of operations: 1) work on the power. 12Vdc, clean, fused at 30A should cover your radio needs for the foreseeable future. 2) read. read some more. ask questions. read some more. the ham radio 101 thread is pretty decent. google exists to help search. arfcom HR forum exists to help directly. 3) stop. consider HOW you will operate all this stuff. where? for what duration? under what conditions? etc. is it raining? is it snowing? will you operate the "mobile" setup from within the truck or will it be contained in a box which you can operate in the truck but also take into a shelter? (btw operating for any length of time inside a vehicle, no matter how spacious, sucks donkey balls). 4) read some more. ask more questions here. 5) get VHF capability, mobile and handheld, incl antennas. 6) figure out how VHF works 7) get HF capability, mobile, incl antennas. 8) figure out how HF works (non-NVIS). 9) figure out how your setup, with your HF radio and antenna, can be utilized for NVIS. note: NVIS is not a cell phone. it doesn't provide anywhere near that level of path availability. there are days when NVIS will work perfectly. and there are days when you will not be able to hear a damn thing. some days will be divided -- hours of perfection, hours of "ok", and hours of frustration. there is absolutely nothing you can do some days -- the best equipment, the best antenna, but the ionosphere is on it's own plan. 10) continue to practice, keep current, etc ar-jedi |