Military VHF Radio Antenna

[codenamegriffin]

I'll start off by saying I'm sorry for falling short on information on this subject matter; so if at any point I seem like I don't have a clue about what I'm talking about, you're right. That is why I'm here.

I'm an Radio Telephone Operator in an infantry recon platoon and I need to know how to get the most out of my radios.

I've been getting very bad range out of my 1523Es. I've been using old long whip antennas, and trying to come up with some solutions on my own. I've tried to make my own field expedient antennas; but the resources available to me are too difficult for me to understand (I've never been trained throughly on the topic). I don't know much about radio wave propagation. I've tried to use different army manuals and people actually in communications jobs; but the manuals are broad and difficult to understand and in MOST cases, I've become as or more knowledgeable than the people assigned as commo.

To get right too it; I want to find a place to buy or a way to make a better antenna with a BNC connector for FM / VHF. When we deploy and often in training we use frequency hopping, and I know that wires have to be specific lengths to get the best reception/transmission possible. It would have to be able to be put up and taken down quickly, and quietly and not stick out like a sore thumb. It would have to be able to work better than a long-whip in crappy terrain, surrounded by woods, and be somewhat rugged. I've been told about dipoles, but I don't know the difference between a half wave, quarter wave....yada yada. And none of the people who I should be able to go for this information know either. I just need something that WORKS!

Am I asking too much? Is this possible. Please, if you are an expert on this subject, I am in dire straight. I need to be able to make comms better. Here's a quick recap...

PRC-119 (or RT 1523E if you prefer)
Better than Longwhip
BNC Connector
Quick, Easy, Rugged (or at least not delicate)
Sometimes getting less than 2000 meters

Thank you

[IdunBenhad]

Hi:
You're getting into a subject that has reams upon reams upon reams of information available.

You are apparently searching for the ultimate antenna that covers all frequencies equally. Sorry to tell you, but that doesn't exist. You and every engineer and ham radio operator and communications experts have been searching for years and haven't found it yet.

Looking at the 1523E on the WIKI, it has about a 50 mhz range and as you said, frequency hopping. Frequency hopping makes an antenna problem, but surely the military thought of this, as well as the designers of the radio, so there should be an effective antenna available for it through the military.

If you want to study the different types of antennas and how to design and build them, look into the ARRL (American Radio Relay League) Antenna Handbook. This book is written for hams, beginners and experienced alike. You will find a wealth of information there at a reasonable cost. Even though it is primarily for the ham radio bands, the design principals cover all frequencies.

Go to www.arrl.org for information on how to get the book, or go to a local Ham Radio Store.

Your post doesn't indicate your location, so I can't locate a store for you.

You might try Amazon.Com. They sometimes have these books for good prices.

Also, you didn't say what power you're using. The radio has 1 mw-100mw-5 watts-50 watts. Makes a difference!

[bmcgeeny]

Gotta love it. The military is turning to DIYC to engineer electronics!

[Aurbo99]

We've been here longer than you know... =) muhahahaha!

[Andy.wpg]

To get right too it; I want to find a place to buy or a way to make a better antenna with a BNC connector for FM / VHF. When we deploy and often in training we use frequency hopping, and I know that wires have to be specific lengths to get the best reception/transmission possible. It would have to be able to be put up and taken down quickly, and quietly and not stick out like a sore thumb. It would have to be able to work better than a long-whip in crappy terrain, surrounded by woods, and be somewhat rugged. I've been told about dipoles, but I don't know the difference between a half wave, quarter wave....yada yada. And none of the people who I should be able to go for this information know either. I just need something that WORKS!

What does 'quickly' mean? Are we talking set up for a few hours (or overnight)? Or are we talking 'deploy it for a couple minutes while we take a drink of water' fast?

I have had amazing success with a 'twin lead j-pole' but there are some limitations to it. Power for one. It can't take a whole heck of a lot of power, and your radios can put out 50W (would probably melt the thing), but 5W is easily handled. It could be designed for your frequencies, but, it would work best at ONE frequency. Everything else would be less efficient.

It's easy to put up (throw a fishing line up a tree and haul it up), but that weight crashing through the trees would probably be too much noise for a tactical situation.

Unfortunately, as IdunBenhad said, the engineers who built the radio have probably come up with the best compromise of efficiency, range, and portability that a lot of money could come up with. Unless you are using a SINGLE frequency, EVERY antenna is a bunch of compromises.

While I support your willingness to research antennas and learn about them (learning is a great thing), I have a feeling that you already have the best antenna you are going to get for that radio.

Good luck in your search,

Andy
VE4RDO

[codenamegriffin]

Thanks Andy for being so straightforward...

I would be using my RT dismounted, so I'll be pushing 10W. No power amplifier, since everything that I have I'm carrying on my back. My freq range is 30 to 88 MHz; which I know is a HUGE gap. When talking to my Battalion's so called "experts" on the subject; they say that the only thing I have to take into consideration when using FM / VHF is getting a antenna that is big, and high. I simply know that that can't be right and they're just giving me a quick answer to get me out of their hair. There are plenty of handbooks that talk about dipoles, inverted Vs.....so on so forth....but they don't tell you enough about anything to actually make one. Resistors? Ground wires? I'm sorry that I'm such a numb-skull; but I'm an infantryman. I know how to close distance and destroy the enemy. I'm not an electrician, I'm not an HAM operator. I'm not an idiot... My Battalion recognizes me as the best RTO in the unit... and this is how little I know. I could asked to get sent to Ranger school to become better at operations, or Sniper School to be better at shooting and recon... But there isn't anywhere I can go to TRULY become a better radio operator, or actually understand how my radio works and how I can make it work better. I can't find ANYONE who can actually help me make one, buy one, or do anything it takes to put them into motion. The most effective thing that we use right now is a long-whip. It's about 7 feet tall....just a straight line...up in the air. Omni-directional. Out in the middle of woods and hills. Some times it'll send 4 or 5k. Sometimes I can't get 2k out of it. The manuals state that I can get 10k out of my equipment. I understand that those ratings are for PERFECT conditions; but there simply has to be something that can be done. The Ranger handbook and Sapper handbook both talk about getting better signal out of all these type of user made antennas; but just don't go into the sort of depth it takes to make a completely unexperienced person understand any of it. I strive to do EVERYTHING I can do to be the best, most effective RTO my division has ever known. I'm fairly sure that I already am; even knowing what little I know. I just need some direction to really understand the underlying concepts of waves.

[IdunBenhad]

Hi:
If you want to see how a dipole is made, look in the Forum "Radio Waves" and look at the first entry in the thread "FM02 Transmitter Setup". The dipole can be scaled to match your frequency, but if that frequency is moved very far, say 1-3 mhz, then the antenna will be out of tune and not respond as it would at the design frequency.

Also remember that the antenna on the far end should be a good one too.

I think the biggest problem here is that you can't depend on using one frequency for your excercises and therefore cannot use an antenna that is cut for a certain frequency. It seems your problem is not the equipment but the lack of training by your Battalion. I would think that within the great big military establishment, there is a school you can be sent to and learn the fundamentals.

It is almost impossible on a forum like this for you to learn about antennas, how to make them, design them, etc.

I am not trying to "put you off" as I very much respect what you do and champion your effort to do it better, but I just don't see how any of us can go much beyond what we have said so far. Most of the participants here are not communications oriented. Perhaps you could find another forum more in the field of what you need to do. Try QRZ.com for one.

I was in communications for most of my working life, and this knowledge and "how to do it" just doesn't come overnight. Sorry, my friend.

[BuzzKill]

Should probably start with something more basic. You need to understand the problem before you can come up with a solution. An antenna is not the only part of the equation here. Power, terrain, and the freqs being used all play a roll in how the signal will propagate in a given environment.

Obviously, the whip is omnidirectional. Are you trying to extend your range using something more directional so you are focusing your transmission? You can't have it both ways. You would have to up the power, change your freqs that you operate on, and or get your antenna higher to get more range.

If you want to learn antennas, start chatting with HAMs. We have lots of hams on this board. Some are the right kind of HAM, and some of the others... well, not so much.

[Andy.wpg]

Thanks Andy for being so straightforward...

I would be using my RT dismounted, so I'll be pushing 10W. No power amplifier, since everything that I have I'm carrying on my back.

Twin lead J-Pole would work then - do a google search for that - the only thing is, the designs you see will be for Amateur Radio frequencies. Some of the pages include the formulas for calculating lengths. I wouldn't design for more than 10MHz range for each one, so you would carry several.

They are made from the 300 ohm twin lead antenna wire that EVERYONE had going up to their TV antenna on the roof - before cable and satellite, that is. They roll up into a small package. It would be worth a try.

You can use a fishing weight and fishing line (fired up as high as you want in a tree with a slingshot) and haul up the antenna - low visibility wire, hard to see in the bush.

You are limited in how high you can go by the coax. Thin 50 ohm coax (like RG-58) would work for (probably) 25' and not much more. That would mean the top of your antenna would be 30-32 feet in the air - would help a lot. I certainly wouldn't want to pack several rolls of anything bigger than RG-58 on my back.

If you send me a PM with your personal email, I'll see if I can come up with some measurements for, say, 40-50MHz - it would be worth giving it a try. But I would HIGHLY recommend that you contact an amateur radio operator that has an antenna analyzer to thoroughly check it for SWR and impedence match to your transmitter before you hook it up to goverment-owned equipment.

Any blown finals would be your problem.......

73

Andy
VE4RDO

[codenamegriffin]

Thanks for the ideas guys; and keep em coming. I can't explain much more as far as the problems I'm having, but one way or another, this IS making me better. Today I asked our commo guys (radio "experts") for a male to female BNC adapter. 48 hours ago, if you asked me what a BNC end was, (I had to ask 4 of them before finding one who knew what I meant) I wouldn't have had the slightest clue. If you showed me the end and asked me which equipment it went to, I would have been all over it. Right now I'm trying to get my head wrapped around this J-Pole idea. Crawl>Walk>Run...


WD-1 Wire - I have as much of this at my disposal as possible. Is this the same (or similar enough) to the 300 ohm TV wire? If not... If I go to radio shack and ask for 300 ohm TV wire, will I find it. It would be better for me not to have to dip into my own pockets, but it wouldn't be the first time I've payed out of pocket for something I'm doing for this big ol' Army (and even tho I'm a recon grunt; I really like doing this stuff). Last thing on WD-1... Do civilians call it the same thing? WD-1 Wire on Google pointed me right to what I was looking for but would a civilian radio expert know what I meant if said WD-1?... would just like to know... Moving on.

I just this second learned that what we would normally call a W-2 cable is just a coaxial cable with BNC ends. SICK!

The layout for the JPole that you directed me to... will it be omni-directional? I'll always be able to figure out an azimuth for who I need to talk to; so I'm trying to get away from omni-directional antennas because if I understand correctly; directional antennas get more range (in that desired range only). Like I said, before I was thinking about a dipole (bi-directional I think) because anything seems better than sending weak waves in all directions.

The lengths that I would be trying to figure out...would I be looking for the length for half-wave or quarter-wave?

You said something about an antenna analyzer... Have you ever heard that called a Primm? I know that a while back, I thought maybe my antennas weren't getting the power they should have, so they said they could hook them up to a Primm. Maybe the same?

Hopefully I can find time at work to do this. You know; learn how to use radios VERY effectively...MY JOB! We get bogged down with some much administrative CRAP, that working on projects like these never gets followed thru. I love the challenge of figuring tech out; but it's just silly that the biggest challenge is finding time to do the challenge.