# Field Expedient Antennas



## genesis98

This is pretty much a lost art in the reserves, it's not given the attention it deserves I know I am not nearly as strong at antenna building as I should be. Could some of you guys give me an idea of some different types of antennas, aswell as what should be carried in a Field expedient antenna kit.


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## Spr.Earl

Yowzer!
I have not heard about this for ages and do forget how to put one up. :
I do remember,you need insulators at either end of your antenna and the line to your radio comes off the middle
Your range is judged by the length of antenna and directiion it's placed?

Am I correct?

Please correct me   if I'm wrong.
Ah another note morse code is no longer used to day.


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## pronto

I used to cheat - I bought an Alpha Delta Sloper kit, and carried that around for years! You can get them on line or at a radio store. 

I also carried 100 feet of cable, wire, alligator clips, PVC pipes, twine, and pegs.

I also had an ARRL basic anntenna design book. You can probably get its latest incarnation at chapters or amazon or direcctly from ARRL. A great book, explained 1/2 and 1/4 wave antennae, lots of information on standing waves, signal chasing, etc. We used to run expedient exercises regularly to see what we could come up with. I would point out though that we also used ACP 125 CANSup 1A, so I am really really old, and this may be nonsensical to everyone except my fellow farts....


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## career_radio-checker

How about a spare antenna ;D


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## Bert

Wheres RadOp when you need him?

If I understand the question properly, antennas typically come as part of a field deployable
radio kit.  You can also build/attach suitable antennas to a deployable field radio kit.
There are alot of radio kits for varous applications so the answer to the question
is broad.  For field deployability, the intention is to set up the system including the
antenna (usually supplied with the kit) as quickly as possible.

The 'net offers alot of MF, HF, VHF, UHF, and microwave antenna theory and product 
information.  It might be a good idea to start reading up on antenna theory basics,
transmission lines, and radio system block diagrams.  

This is a good starter:

http://www.arrl.org/

http://www.scanshack.com/antcal.htm

After that, various radio kits come with with own antennas.  Sometimes, the antennas are
busted, damaged feed line, or defective connectors, or the radiation pattern isn't suitable 
for the application.  Then a best effort custom built punch in the face antenna has to be 
constructed for the desired functionality; directional or omni-directional for the band, 
frequency, and power output.  Understanding the application, the characteristics of the
frequency band, the possible locations of stations (yours and enemy), output power
levels, and reception limitations lead to figuring out what type of antenna to build.  

Having test equipment to measure the SWR and field strength is nice, but if you have
to eye-ball it, you may wish to have quick antenna design memorized and calculation
in your head.  For instance, a 6.8 MHz HF quarter wave dipole has legs approximately 17.25'.  
A higher frequency will have shorter legs, a lower frequency will be longer.

Radio work is fun.  Enjoy the job.


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## Pte.M13

made a couple antenna's last month, overall one of the better classes i had all summer, we made one sorta like a tee pee with 3 radiating elements coming down from the cobra head (lets you connect your wd1 to your coax) at the length appropriate for your freq, and then at the bottom we used three ground plane rods (from a gpa antenna kit) taped together into a triangle, resisters at each corner taped together in a hell of a mess with the rods. then used a pully system to keep it up in a tree. 

found that the better your measurements were, the better your comms would be away from the freq you made it for... some could get clear comms across a field for any VHF freq, others got worse because of bad measurements and other errors.  sadly we never really tested actual range.


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## Sig_Des

I can tell you that with a field expedient antenna, properly made, and at the right time, you can get clear comms from St-John's to Petawawa. 

I've also heard of people getting comms from Canada to the Golan Heights


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## Jason Bourne

Maybe not to slight the ongoing REG QL3 courses going on but there isn't enough time spent on field AE anymore. I think I built one on the entire course. It did work too...hooked that bad boy up to a 138 and talked in the sun all day  But I've heard crazy stories about guys attempting AE out of C7's etc etc lol. Ahh good time.

Jason


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## Radop

Bert said:
			
		

> Wheres RadOp when you need him?
> 
> 
> 
> 
> 
> 
> Did I hear my my name?
> 
> What type of frequency range, directional, non-directional, mission, etc are all the things you have to consider when desiding what to bring.  The 522 has an antenna adapter that mounts onto the antenna base but has a push clamp to put in WD1, coax cable or other type of wire you bring to make an antenna.  Most people forget the most basic of techniques which is to place the wire into the broken end of the antenna, attaching the broken ends togeather then taping or tying the wire and antenna together.  You then use a branch (perferably Green to help conduction and for suppleness) to hold the whole thing together.
> 
> A basic expediant antenna kit would consist of 100' of wire, a connector of some sort (cobra head being best), insulator and pop can or resistor.  100' of cable will tune to any antenna in the HF, VHF and higher spectrums and can be made directional (long wire), bi-directional (di-pole) or omni in the case above or field expiediant vixam.
> 
> Although a fading art, like HF, I feel it is something that we will eventually come back to as we will again see the need for it.  What do you do if you get into loc to find that the B&W is broken and you have to send comms back 200 Km?  The obvious answer for us radops is to build a multi freq antenna because when night hits, the freq you were using during the day will probably not work at night.
> 
> If you do the math as well, 234/freq will give you a quarter wave antenna.  As we seldom go below 2 mhz, 100 feet is pretty close to that low a frequency.  That is why the 100' (plus easier to remember than 103' 9 3/8ths".
> 
> Well that was a load off of my mind, shut up Cnd Sig!!!!
Click to expand...


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## SigPigs

Yes go to the ARRL and also to rac.ca which is the Canadian equivalent. Never ever BUY anything, why? You are throwing money to someone for the chore of simply soldering some wire together. Do it yourself and save a bundle. As far as wire antennas go there is NOTHING that can't be made as well or better then ANYTHING you buy. 
Grab the formulas on those web sites and use them. Look at NVIS antennas, look at all the types and you will have more ideas of what to build and why you want a particular one. There really aren't a lot of choices though, it's either built for local comms within 400Km and is NVIS, or it's built for long range comms. People don't understand that comms are routinely made around the globe on a few watts, yes a few watts only. So when you have the luxury of 1Kw or 100W then you can normally do what you want with the right antenna. 
Also realize the HF antennas are almost always a compromise, you will never get it long enough or high enough as it should be, so it's a trade off that we all have to live with. For example a 7 MHz antenna ideally should be around 64ft off the ground. That almost never happens, that's a long way! So you make do with what you have. 
Oh and Radop, you would not use a green branch for an antenna, yes great for suppleness, but bad for reducing efficiency of your antenna. Anything near an RF field that will conduct is bad news for your antenna. 
This is a subject that could fill volumes and yet can also be done simply and quickly with a small amount of knowledge. 
Email me if anyone would like more in depth info on antennas and HF comms. I can get you some great links etc....


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## Radop

I was talking about a veh antenna with the green branch so that if you hit a overhanging branch while on the move, it would be able to flex with the strike.  It is also attached to the tx part of the antenna so it doesn't matter if it will conduct or not.  I agree though for a field expediant antenna such as a multi-freq dipole, wood is used to insulate and should be dry and old.


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## armyguy62

I was a Rad Tech with the Infantry, Armour and Artillery and worked hand in hand (so to speak with my Rad Op brothers in arms building a lot of antennas....best resource I found was the (I hope this is right....has been a while) ARRL (Amateur Radio Relay League??) handbook, basically a guidebook for those in the hobby of ham radio. It was a fantastic source of info on expedient antennas, transmission lines and how radio works (particularly HF)


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## Shilly

Hello;
 Alot of good information in this thread, and Sig ops have seemed to have gotten away from Antenna construction with the roll out of TCCCS. So i am going to add a few pieces for field expedient antennas.
 The information is taken from B-GL-321-006/FT-001 , SIGNALS IN BATTLE Vol 6 , SIGNAL FIELD HANDBOOK , Chapter 7.
 Enjoy!

http://www.geocities.com/fallen_angel_2001ca/pg247
http://www.geocities.com/fallen_angel_2001ca/pg248
http://www.geocities.com/fallen_angel_2001ca/pg249
http://www.geocities.com/fallen_angel_2001ca/pg250


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## G-Fresh

Good to see that people are becoming more interested in the lost art. 

I have been lucky enough to teach at the School and on an Infantry Comms course.  Teaching the construction of field expedient antennas was probably the most enjoyable class I have ever taught.  The students seemed to enjoy it as well.  When the construction was done, the students were pretty impressed that a some WD1, some 88 tape, and some buttons actually came together to create a working antenna. 

Having the access to the information is great, but having the knowledge is always better.

"Give a man a fish, feed him for a day.
Show a man to fish, feed him for a week.
Teach a man to fish, feed him for a lifetime."


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## DG-41

Now if I can just get one of you Sigs-types to teach us how to build a field-expediant 522 battery, life would be good.

DG


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## Carbon-14

They should bring back those hand-crank batteries..  I believe they were for the 515.   Never used one myself tho


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## Radop

Carbon-14 said:
			
		

> They should bring back those hand-crank batteries..  I believe they were for the 515.   Never used one myself tho



I did, they suck not to mention to make you tired while making a hell of a racket especially with the 15 ft whip.


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## Weekendsig

The ANPRC 522 NI CAD battery (the square one) is junk. Get a grip on some of the Lit ones you and you can operate almost 3 days (depending on usage) and still have 60% battery life. 

That goes with all NICAD batteries for the radios.


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## Hawk

A lot of years ago I lived in a trailer in the mountains and acquired a Model 19 radio. I hooked it up with a field-expedient that was a wire from the back of the radio, out a window and up to the roof. Mid-way we soldered a spark plug. That wire was attached to one that went angle-wise front to back of the roof. I reached out of the Elk Valley to all over the world!

When I was in Reserves we got a bit on field expedient antennas, not much. We had an old short wave radio at home, so, as an experiment at first we hooked it up with an L antenna-back of the radio up to the ceiling then along the ceiling to the other corner. We were living in a condo at the time-virtually a row-house with a metal beam running under 5 units. It made a great ground plane with a wire running down to it and attached with an alligator clip.

I wish we'd learned more. It was the fun part!


Hawk


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## Weekendsig

The handcrank was an interesting peice of kit but it took a long time to charge the battery and you could only turn it so fast without screwing up the battery. But the idea was awesome.  Also provided supervisors with some productive corrective training besides serializing mod spikes.


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## sober_ruski

Field expedient battery:


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## Can_do

I had to teach this a couple months ago and re-learn it myself. Field Ant are more used to gain range. Throw it up a tree. HF You need to be more careful of the length, getting the cobra heads and Insulators is hard, no one seems to use them as much with the self tuning of couplers these days.


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## chrisf

So here's a long shot...

I've seen it a few times, I know I have a copy, but i can't for the life of me find it...

It's a booklet with field expedient antenna, and field expedient antenna repair ideas... well illustrated(May have been a US army publication, but I'm fairly certain I remember it being Canadian), maybe a dozen or so pages long.

Anyone have a copy? Anyone who has a copy willing to scan it? Or anyone know where I can find a copy?


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## George Wallace

You can try contacting someone at the Armour School.  Expedient Antennas were taught to TQ3/QL3 Armour students (Now DP1) and also on the CATS Crse at the Armour Communications Sqn.  I know I have several handouts on Field Expedient Antennas, Patrol Antennas, Ground Plane Antennas, etc.  If I remember correctly, all you need is 105 ft of WD 1 Field Wire and you will be able to cover the vast majority of freq waves.


Or you can look at these links:

http://www.armymars.net/ArmyMARS/Antennas/Resources/usmc-antenna-hb.pdf

http://www.google.ca/images?hl=en&biw=1259&bih=564&rlz=1R2GCNV_en&q=field+expedient+antenna&um=1&ie=UTF-8&source=univ&ei=pKEOTbmVEMmcnwf9kpywDg&sa=X&oi=image_result_group&ct=title&resnum=4&ved=0CDsQsAQwAw

http://www.globalsecurity.org/military/library/policy/army/fm/90-5/Appg.htm

http://feraljundi.com/2009/06/12/technology-the-cantenna-a-field-expedient-wifi-antenna/

http://www.cavalrypilot.com/fm17-98/ch9.htm#s4


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## chrisf

Not really looking for information on field expedient antennas, I have all sorts of that, and I have a half dozen different handouts I've collected over the years, but i shall have a look through those links later. It really is a dying art, and a shame, because there a lot of effective simple antennas you can build for different conditions.

It's a very specific handout that I've got in my head that I'm thinking of, about a dozen pages, very well illustrated, almost comic book style (Which is why I'm thinking it may have been an American publication, maybe vietnam war era). All about repairs and expedient antennas. Quite informative, yet written so the lowest common denominator could understand and use.

If anyone knows what I'm talking about, and if they're kind enough to scan it, would love it. If I find it myself, I'll scan a copy and post a link.


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## chrisf

George Wallace said:
			
		

> http://www.cavalrypilot.com/fm17-98/ch9.htm#s4



Basically took section 4 in this one, and turned it into a comic book. Dandy little handout, if I can find the thing, I'll turn it into a PDF.


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## Bert

I believe you're referring to this http://www.arrl.org/shop/The-ARRL-Antenna-Book/


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## chrisf

Not even close, it's a little comic book sort of booklet.

Sort of like this

http://143evac.bizhosting.com/m16comic.html

Only not quite as elaborate.


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## josh54243

I made a mini Pocketmod book a while back if you're interested


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## MedCorps

The US publication you are looking for is called: 

"What's Up?" Know how to repair and fabricate antennas.  TC 11-5. 29 April 1977 

It was issued in the CF as B-GL-T11-005/FP-000 

A small little 45 page pamphlet in five parts: 

1) Antenna Types 
2) Antenna Connections 
3) Antenna First Aid (Field Expedients) 
4) Formulas and Quick Reference Charts 
5) Reccomendations and Reminders. 

Great little pub.  I have had mine since I was given it in 1989.  

Cheers, 

MC


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## Radop

Wow, 6 yrs ago make a statement on a site and re-read it again to find out that what I said came true!  Too bad I can't get PER points for that, lol. 



 :snowman:


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## Edward Campbell

Not exactly a _field expedient_ antenna but, thanks to a US company, a better way to package SATCOM antennas for rapidly deployable units.

http://www.wired.com/dangerroom/2014/01/army-communications-balloon/


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## VVVjimmy

I cut a few AE before I even joined the military, so it was a bit of a refresher, and we didn't cover it in in great detail on my 3s. We did however make up the basic dipole arrangement with insulators and a cobra head for the 138. 

Long story short I believe we've gotten away from expedients because they were most effectively and commonly used with HF. Seeing as Satcom and such has really decreased the use of HF (which is a pity in my eyes) we naturally saw a decrease in expedient AE. 

As long as you remember the formula -    Wavelength = Speed of light (300 for M, 926 for Ft) / Freq in Mhz then you're good to go.

The best one I ever made was for an old artillery warrant. I had an old CRT television in the back of my LS in Shilo and was playing games on it. He found out and demanded that 'as a jimmy I had to get him the leafs game.'   This was when CBC Winnipeg still broadcasted over the air.

I took WD wire, wrapped one strand around the outside of the coax on the tv, stuck the other into the center. Ran it up to the roof where I unscrewed one of my VHF AE and laid it on it's side. Connected it all, tuned to the channel and turned the Spud 1 on its side until it came in clear. He was very pleased haha.


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## materialpigeonfibre

Field expedient antennas are not just for HF and VHF!

Check out this Iridium field expedient antenna! SATCOMM!



(Half of the dipole drawn in because it has broken off)
1/4 wave (About 2.6 CM) on each side of the dipole. Shaped in to a wavy shape (to have a better impedance match).

Silicon at the center. Prevents rain from getting in and spoiling the coax.

1/2 wavelength from the feed point is the reflector.
A pickle tin from the camp cooks. It is around 3x larger than regular tin lids.  It is _NOT_ electrically attached to the coax. It is simply held in place with some silicone.

The connector is a TNC-Male. It connects to the Iridium.

There is just enough coax to get outside the mod tent and up a couple feet. Zip-tied to a cam-pole.

The coax has 3dB loss, the antenna is horizontally polarized (resulting in 3 dB loss because Iridium is RightHandCircularPolarized).
Overall you only have 1/4 signal strength. But it works! And it works better than nothing!

The same theory at HF applies for Satcomm. Get creative. Make comms work.

Edit:
Iridiums standard for loss is -3dB. So this isn't that far off.
I had the pickle tin spaced off 1/2 wavelength because I was far up north and wanted to hit the satelites near the horizon. It never failed.  But if you move the pickle tin higher (to .25 wavelength), it will send more signal straight up. Might be better near the equator.  Or it might be too directional and drop signal. Try it out and find what works for you.

As for what should be carried, I would take a look at ACIMMS? or DBB? first. There might be a little handbook to carry somewhere there.
Those aidememoires sure come in handy. When you're cold wet and sleep fudged, few things help like being able to blindly follow some instructions and have it work. I had a rash on my leg from walking around with so much paper in one pocket in a ziplock.  But it has worked out more often than not.

https://www.marines.mil/Portals/1/Publications/MCRP%208-10B.11.pdf?ver=2017-03-15-092827-423


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