Manpack communications

Discussion in 'Survival Communications' started by stg58, Dec 12, 2014.


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  1. stg58

    stg58 Monkey+++ Site Supporter+ Founding Member

    For a while I have been banding about creating a manpack HF/6-Meter/2-meter/70Cm rig.
    Undoubtedly many are out there here are 2 of the many.




    Yaesu FT-857d manpack...home brew

    Home brew manpack inspired from video seen here on youtube by a gentleman in Norway....Pack frame is half inch copper pipe and fittings,some scrap aluminium for mounting plates all painted olive drab...SGC vertical for HF and old Diamond for VHF/UHF...FT-857D and LDG AT-200 pro tuner...Military MSA Sordin 75310 headset with modified PTT hook up and H-250/U handset....16.2 volt 10 amp hour lithiumhttp://7-55MHz Portable Vertical Antenna


    Ham Radio Expedition - Mountain-topping w/FT817 & Buddistick

    5 Watts east coast, west coast and Alaska..
     
    Last edited: Dec 13, 2014
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  2. Airtime

    Airtime Monkey+++ Site Supporter

    When you build yours I encourage you to not use copper pipe and fittings. It is heavier than you need but the frame will be soft and will easily bend and distort. I know from first hand experience with copper frames. Doff the pack and drop it hard and it will bend and might be a risk for the radio gear. Electrical EMT conduit is pretty light, much stronger and extremely cheap. You can fill a section with water, freeze it hard and then bend it around a mandrill with a much tighter radius than a standard conduit bender without it flattening. It will bronze braze quite well too for joining.

    AT
     
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  3. HK_User

    HK_User A Productive Monkey is a Happy Monkey Site Supporter

    They may have used Rigid copper tubing and brazed or used silver solder.

    Or Not.
     
    Last edited: Dec 13, 2014
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  4. stg58

    stg58 Monkey+++ Site Supporter+ Founding Member

    Great points on the frame, how about titanium [sarc2]
    Still debating but that Norwegian ham put some thought and work into that frame.

    For some reason the full link caused server errors remove the ** and replace with dd...

    I have used the bu**istick antennas at field day and they work well.

    Designed as a multi-band, portable antenna for 40m - 10m, the Bu**istick™ is an excellent performer with any rig up to 250 watts. It works exceptionally well with the FT 817, Elecraft K2 and KX1, IC 703 and other QRP rigs.

    The Bu**sistick comes packaged in a compartmentalized 1000 denier cordura portfolio bag and includes 2 aluminum arms (blue or black), one standard telescopic whip, one adjustable coil, 2 coil clips, mounting kit, a complete counterpoise system, as well as operating manual.

    Included is one 31' radial on a line winder for use on all bands 10 - 40m.

    The mounting kit for the Bu**istick™is a mounting plate and SO-239 adapter for a straight coax feed. A rubberized clamping knob is used to secure the plate to a clamp or tripod (1/4" x 20 threads).


    Accessories for the Bu**istick™ include an adjustable clamp which allows for a full range of motion and permits the user to operate the Bu**istick™ from a picnic table or a condo railing, for example.
    You can also mount your Bu**istick™ on a mini-tripod for use on the ground or on the deck or patio at your home.

    http://www.bu**ipole.com/buddistick.html
     
    Last edited: Dec 13, 2014
  5. kellory

    kellory An unemployed Jester, is nobody's fool. Banned

    I like it, when folks share alternative methods of doing things. There is always more than one way to do something, but most folk will seize up if the "right" tool is not available. I like working around corners, as it were.
     
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  6. Airtime

    Airtime Monkey+++ Site Supporter

    Even the heavier type L rigid copper pipe and fittings will bend in a rectangular frame like in the video with only a modest load. The fittings are clearly the weakest link. Been there, tried that years ago when needing a frame for some special video and lighting equipment we were putting into a modestly corrosive environment. Ours was a similar size and the copper wasn't close to strong enough for about 20 pounds of stuff.
     
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  7. stg58

    stg58 Monkey+++ Site Supporter+ Founding Member


    That was a reason for posting to get some input on creating a Manpack (or Womanpack) rig.
     
  8. kellory

    kellory An unemployed Jester, is nobody's fool. Banned

    I'd look into fiberglassrods for the frame, or carbon fiber. (If I was trying to stay light. ) But even welded box steel tubing would not wiegh much in the quanities needed.
     
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  9. BTPost

    BTPost Old Fart Snow Monkey Moderator

    The effectiveness of HF ManPack Radios is ALWAYS limited by the RF Ground that the Antenna has to work against. This is why in the modern World, HF Comms is mostly limited to Mobile, or Mobile/Portable wheeled Comms setups. There just is no practicle way to get an efficient Antnna, within the Laws of Physics. With 6 Meters and above, modern Handheld Equipment, Ranges are much better than ANY HF .MIL ManPack that were Pre 1990's Vintage. If one were working in a Desert Environment, then a Balloon Antenna works well, but in a Jungle or Forest environment, that just is impractical.
     
  10. Airtime

    Airtime Monkey+++ Site Supporter

    Titanium would be wonderful but it's very expensive and difficult to weld. A light steel or aluminum tubing would be fine. Steel construction with MIG welded or brazed joints would be fine. Aluminum with TIG or MIG welded joints would be wonderful too but if those techniques or outside your workshop's capability here are a few other thoughts. There are some aluminum army surplus frame packs that might work with minimal modification. Other techniques for construction would include bending tubing and T joints can be made by flattening an inch of tube, bend the flat into a J shape and pop rivet. See the Alice frame in picture.
    [​IMG]
    These Alice packs also had shelves for them and a couple of those with some modification might get what you need.
    Shelf, Alice Pack - $5.99 :: Colemans Military Surplus LLC - Your one-stop US and European Army/Navy surplus store with products for hunting, camping, emergency preparedness, and survival gear

    Few other ideas:

    Allen Pack Frame Backpack Padded Shoulder Straps Hip Belt Mossy Oak

    [​IMG]
    If you have money to burn:
    Tatonka load carrier black:Amazon:Sports & Outdoors

    Have fun.
    AT
     
    Last edited by a moderator: Jan 29, 2015
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  11. kellory

    kellory An unemployed Jester, is nobody's fool. Banned

    If you are only looking at about twenty pounds, I see no reason this could not be framed with 1 1/2" schedule 40 pvc. Maybe even less. With no metal to possibly cause interference issues.
     
  12. BTPost

    BTPost Old Fart Snow Monkey Moderator

    Interference???? Just what interference, could the PackFrame cause, to HF Comms? the whole point of using a Metal Frame is to start to provide a source of RF Ground, for the HF Antenna System, such as it is. So what one is looking for in a ManPack HF should be a Tradeoff, between Metal Surface Area, and Weight. Still, no matter WHAT one does, an "Efficient ManPack HF Antenna", is beyond the Laws of Physics, so is a compromise just going in.
    This is why all .MIL ManPack Radios will be in the 88-10o Mhz Military Band, even clear back to WWII, and have only local AoO Comms Capability. These were used to relay Scouting Info back to Company, and Regiment HQs where the Mobile Comm Vehicles would then Relay back to Brigade and Division HQ via HF Comm Links.
    If you look at modern .MIL Comms, the Squad Comms is all Short Range, Tactical, and the Platoon Commander stays close to the Platoon Hummer with Company Comms installed. Then the Company Commander keeps watch on all his Platoon Nets, and his Regiment/Brigade Net, which then get aggregated and sent up to Divisional Comms, and on up to Corps and Army Comms, if there are such Units in the Deployment. Everything is done in Vhf/Uhf until Divisional Comms, and then it is Microwave/SAT based on up the Chain of Command. HF is kept around for backup, should the local Nets fail, but bandwidth on HF is severely limited when compared to the normal Comms Setup. This is how Audio, and sometimes even Video, from the Squad Level can get all the way to the CIC, in the Situation Room, all thru a series of Relays, up the Chain of Command. Recently, (last few years) the Predator Drones have been fitted with Relay Gear, that can uplink Squad, and Company Comms, directly via SAT to higher Commands as Mission Requirements demand. Look at the GI Jane, and Zero Dark Thirty, Movies for how some of this Works, and has evolved since Vietnam, and the SandBox Wars.
    What get Good Men Killed, is when the Platoon and Squad Guys get into trouble, from Bad or NO Intel, and the Company, and Brigade Commanders, do NOT keep close track of is going on, and do NOT have a Fast Reaction Force Ready to go, at thew first sign of Trouble. Ala Lt. Mike Murphy debacle. Spec Ops Personnel not getting the support of the local Brigade/Regimental Commanders, back at Base.

    Ok Rant Off.....
     
  13. kellory

    kellory An unemployed Jester, is nobody's fool. Banned

    I've said before, I don't know antennas yet. But I know metal can shield things or cause interference in my line of work.
     
  14. ghrit

    ghrit Ambulatory anachronism Administrator Founding Member

    It can do that. Saying so, it's apt to be minimal and can be tuned out readily if radio comms are on the plate. The key is an antenna that is some distance away, as in large uneven fractions of a wavelength. Also, if using a metal frame, it has to be grounded, both safety and rf grounds to keep the rf tamed. Long wire and end fed antennas directly connected to the xceiver just about have to have rf grounds to keep rf burns off the hand that runs the gear. (I have some rf in the house that regularly trips one of my GFCI outlets. Haven't found out which frequency does it. Yet.)
     
  15. Airtime

    Airtime Monkey+++ Site Supporter

    There is a premise that I picked up on you guys aren't, but maybe I did that incorrectly. The question with the manpack rig is does this need to be operational while on the move? Or is this just a transportation system and non-mobile field deployable antennas are to be used from a fixed location?

    I concluded, maybe incorrectly, with the comments in the OP that transmission while on the move was not in the plan, the rig was to get from A to B then set up an antenna in 5-10 minutes like the Buddistick in the field and work from just the one location for a bit. I was thinking like ARRL field day.

    If my presumption of the latter was correct, then frame interference, RF burns and ground planes are likely not an issue as the field deployable antenna systems like a Buddistick, long wires, 43' portable verticles, etc. should resolve those.

    Perhaps stg58 could clarify that for us.

    AT
     
    Last edited: Dec 15, 2014
  16. GhettoPass

    GhettoPass Monkey

    Generally speaking, metal not part of the antenna system could cause interaction with your antenna. Sometimes good and sometimes bad. An example of how metal might effect your rx/tx would be a metal structure or wire parallel and abeam your antenna. That same metal or wire structure may be separate yet part of your antenna system, working as a reflector or director to your antenna system. Google "yagi antenna". A good book for anyone wanting to learn about antennas would be the ARRL Antenna book.
    ARRL :: Antennas :: ARRL Antenna Book 22nd Edition
    @op Beautiful job! I'd like to do similar using Alice frame with shelf as starting point.
     
    Last edited: Dec 15, 2014
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