Tactical Delta Loop - HF - Directional Antenna (Intermediate to Advanced Operators, General, Amateur Extra)

By the time you're building this you probably (should) have some of your basic skills down, and be a General or Amateur Extra licensee, have an HF rig and be about ready to run in the field.   

I give it five stars for cost, simplicity, ease of use, portability, robustness in wind, time to set up and take down, as well as capability - it transmits and receives very well.  I love that you don't have to lay out radials, doesn't need supports to keep it vertical, don't have to put a counterpoise on it, and it's also directional.

I can have this up in about 10 minutes - compared to 20-45 with some other antennas, which, when it's freezing cold or in an emergency is a significant consideration.

This cost me about $110 to build mostly using things I had already laying around - if you don't have any of the supplies it could run around $150 though the commercial/store-bought models start around $500, but this is significantly more robust and can endure a lot more than the pre-made antennas, in my experience.  For ERC you're going to want simplicity, durability and robustness.

 This is just an example of how I built one of these, there may be better ways, cheaper ways, faster ways, easier ways but this works really well for ERC activities and I'm very pleased with it.   I have and have used a DX Commander, a Wolf River Coil telescoping vertical antenna, and also an end-fed random wire antenna run up into the trees, a half-sloper end-fed wire antenna, and this is my pick hands-down for field HF operations.

Here's one of our regional ham's video of his set up in his front yard.

Supplies for building:

1 ~3' rebar stake or copper rod to drive into the ground to hold up your antenna (Home Depot/Lowes). + Hammer/camp hatchet for driving it. 

 This is said-stake in the ground, you can see I painted my gear a high visibility pink so I don't lose it in the grass or in the field, and so people are less likely to trip over it, but also, it's obviously mine so nobody in the field can confuse my equipment with theirs.

2 - 20' fishing poles with guides (eyelets) meant for deep sea fishing or surf fishing (available on E-Bay for about $30 ea).  If you get longer ones you're back into susceptibility to wind and the tips becoming more fragile like the telescoping whips mentioned earlier, and regular fishing poles aren't robust enough - flexible and durable, though flexible isn't the goal in this case - but unlike the vertical antennas, these are going up at an angle and will be connected to each other by the wire loop. 

1 - 5:1 balun/unun - 500-2500Ω - available on ebay for about $30 if you build it yourself which just requires a bit of soldering. 

Conduit pipe - so that your fishing pole handles can fit over it securely - mine was 1" diameter and the total length was about 30", so if you got a 3' section of conduit and did some cutting you should be fine.  Mine also had a 1"x6" strip of steel for hanging the balun/unun off of.  A friend of mine did the welding for me.

2 -  2"x3/8 sheet metal screws with lock washers, flat washers, and wing nuts.

75' (minimum) antenna wire - here's some from DX Engineering that's high visibility - which would be nice - and here's another larger spool from DX engineering - you're going to be using the wire if you're doing this at all for any length of time, so it won't be a waste and it's always a great idea to have more.

 2 alligator clips for your wire - they will need to fit through the eyelets on your fishing pole (which is now an antenna mast), and you'll solder them to the end of your antenna wire.

2 3/8" 1/2" diameter wood screw eyelets - you're going to break off the last section of your pole off the very tip (it's too fragile at that point to be a part of the antenna) and then clip the last guide (eyelet) off and insert the wood-screw eyelet in - make sure your alligator clips will fit through the eyelet before you assemble everything. 

Thread your wire though the guides and set your poles into the "Y" connecting them, connect the wires to the balun.  I broke off the guides on my fishing pole, I don't remember a specific reason why I did it, you can try it with or without the guides.

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You'll also want coax with PL259's on the ends of them, you can buy 25' sections with barrel connectors if you need it - here's a bit of info on purchasing coax.  I had to get a BNC/SO239 connector for my Xiegu X6110. 

Here's my coax connected to the X6100.

 This is my balun hanging off the mount with the coax running in, an alligator clip on top and one running in the bottom.

 

 

 

 

 

 

 

This is what it looks like from a side-angle , ultimately you'll have a giant, inverted-triangle of an antenna.  

 

 This is a loop and therefore a directional antenna so typically, you'll have to line it up so that it's "in line" with the direction you want to transmit, and you may notice that you receive better depending on which way it's oriented. Here's a diagram from around the web on the radiation pattern for a loop antenna.

I've played around with the connections of my alligator clips and run both a Rig Expert Smith Chart and SWR Chart, as well as my Xiegu X6100's SWR chart on this, and have been reading about 1.1-1.2SWR on 3.810MHz. Most radios you would hook to this in the field are going to have an internal tuner, so you should have no issues with resonance and a low SWR.  As with everything in amateur radio, play around, and have fun.