Manpack communications

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..

 

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

 

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

Or Not.

 

Great points on the frame, how about titanium
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

 

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.

 

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.

 

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

 

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.

 

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.

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


If you have money to burn:
Tatonka load carrier black:Amazon:Sports & Outdoors

Have fun.
AT

 

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.

 

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.

 

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

 

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.