EARCHI End Fed HF antenna

kaena

You’re looking at my favorite view in Oahu- one you’ll likely never see in a travel guide, never take a tour there, and probably never know you could even get there-till I let the secret out. The folks who live on Oahu know it as Ka’ena Point, an outdoorsman’s little slice of Heaven. Between the locals and the ha’oulis four wheeling, the zero dark thirty fishermen looking to snag the next giant ulula at 0300, or the beachgoers looking for a private cove for an uninterrupted private day at the beach, to a certain wild-eyed Platoon Sergeant taking his guys out to kill pigs with his Hoyt bow (he was a feral man), this little secret on the other side of Hale’iwa is an amazing place with a lot of great memories. 

Fun stories, very fun times. Oahu or ‘The Meeting Place’, the capital of the Hawaiian islands, is truly one of the coolest and most unique places on Earth to visit. Hawaii also was a big leap forward in my skills with radios- both as an Infantry RTO as a young Joe and an avid CBer doing stupid things in a rusted out $600 K5. But from there, I really started learning the science behind a lot of the skills I’ve gained since, including having to build improvised low band VHF antennas from breaking the ASIPs Whip (blackhawk door on the way to Kahuku…whoops…). Regardless, it laid the foundation amid seemingly endless cycles of road marches, KoleKole runs, and deployments to Iraq with a tight Brotherhood united by the bond of the hardships of training (and tearing up Kemo’o Farms).

1005161420So with that I jumped at the chance to test an antenna offered by the Emergency Amateur Radio Club- Hawaii (EARC-HI). As the title implies, it’s an End-Fed antenna not unlike the LNR Trail-Friendly, previously reviewed here and seen to the left on the table top. While similar in the basic design, there’s some critical differences. First, LNR’s end-fed is rated for just 20W Peak Envelope Power, meaning it’s a low power only antenna. While ruggedly built, it is fed into a spindle which may be a weak point. I say may be, because it’s very well built, but anyplace where components meet is a potential failure point.

Moving on to the EARC-HI design, it’s probably the simplest antenna out there. The matchbox houses a still relatively small torroid with one critical difference- it handles 100W. The design is simple and robust, with just one sole strand of #18 AWG. Put an insulator on the run end and attach the lead end, hoist, and you’re set. While it doesn’t pack up quite as tight as LNR’s antenna, it’s still nothing to complain about, and is simpler to fix should something break. Also built into the design is an attachment point for a counterpoise wire, turning this antenna quickly into a dipole if so desired. It’s feedpoint is a standard UHF connector vs. LNR’s BNC, which is likely a little more versatile for using pre-made runs of coax but that’s really a matter of personal preference. A lot of the SOTA and NPOTA guys love BNC connections, and it works fine too, so this really is a moot point, but a data point nonetheless.

Performance

1005161455Hoisted in a tree, the matchbox nearly disappears and slides through branches like they’re not even there. She’s just as fast getting in the air as the LNR, and every bit as stealthy. Getting it around 15ft up was absolutely no trouble and took just a couple minutes to rig.

1005161455aBacking away, the run end of the antenna disappears among the trees. If it wasn’t for the bank line in the foreground, you’d never know the antenna was there. It’s a very clandestine antenna.

1005161506For this test the End-Fed was rigged to my Yaesu 857D and LDG auto tuner powered by a 12AH SLA battery. While not the most compact setup, this rig and test simulates conditions likely for a disaster scenario and operating in a fixed position, not unlike a signal section inside a Tactical Operations Center (TOC) and one nearly ideal for Survivalist considerations. A tuner is absolutely required to use this antenna, as it’s not resonant on any single band (although you can cut it to be resonant using an antenna analyzer) but the broad range of this antenna as-is (7mhz-54mhz) lends itself to a high degree of versatility. The first test is my go-to NVIS band, 40m, scanning for any band activity. Although HF conditions are rough for SSB at the moment due to the bottomend of the solar cycle, contacts most definitely ARE possible, even with very low power, as folks attending PATCON last weekend observed with me running just 2.5w and making SSB contacts in VA. 40 was in rough shape, but with just 10w out I managed to make positive contact in WV, OH, PA, and relayed a station in FL getting a sitrep from a station in Cuba. That’s right, trial by fire- while Hurricane Matthew is wreaking havoc and destroying communications infrastructure, radio amateurs are on the air still, with wire antennas, coordinating communications. 1005161629Moving up to 20, the noise floor is still pretty rough, but the Hurricane Watch Net is still on the air and relaying information in real time. I boosted my power output to 15W and had no problems making contact. 14mHz is NOT an NVIS band (it doesn’t propagate that way) and antenna height makes a world of difference, but in this case the antenna worked just fine.

As a shortwave listening antenna, the End-Fed once again shines. WWCR came in stronger than the local FM stations, with zero fade that’s usually the case when listening on shorter length wire antennas or whips. Many other stations were coming in very clear, including several foreign stations, but I didn’t take the time to log any of them as I moved back to 40 to continue working. Compared to the LNR, the EARC-HI has less noise, likely due to the larger torroid. In both tests the antenna was placed in the same tree, albeit at different times.

Concluding Thoughts

This is an antenna you should have. Both this and the LNR are great pieces of kit, but if I only could have one, this one edges out due to it’s absolute simplicity. While the LNR is smaller and marketed to backpacking QRP-only radio enthusiasts, this model is more general purpose having the ability to handle up to 100w and being very simple in design should repair ever be necessary. It disappears into trees making a very stealthy package, and is so rapid in its method of deployment that its ideal for EMCOM and disaster preparedness, as well as those restricted by HOAs or the occasional operator who can’t justify investing in a tower.

The EARC-HI club and the antenna’s designer, Charles Hanebuth, made this antenna for all of the reasons it was tested and posted here. It’s a heck of a good design by folks who take amateur radio and it’s role in disaster preparedness very seriously. For what it costs ($40 for the kit/ $56 pre-assembled, both prices include shipping) it’s an excellent investment. The plans are available here as well, for those who wish to source all of the components locally and roll your own.

A huge Mahalo to the EARC-HI club…you guys rock. Have some Maui Mike’s for me!

bronco-brigade

 

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14 thoughts on “EARCHI End Fed HF antenna

  1. Pingback: Brushbeater: EARCHI 100W-Rated End-Fed HF Antenna | Western Rifle Shooters Association

  2. Deplorable B Woodman

    I was going to ask what unit you were with in Hawaii, but your logo at the end told me all — 25th Dimension, the Electric Banana Leaf. When were you there?
    I was with the 625th Maintenance 88-92, at Schofield Barracks.
    And yes, I was commo then, and am commo still.
    You can never get that red volcanic soil out of your clothes or your blood.
    ALOHA!

    B Woodman
    III-per
    kc7jds

    I’ll have to get one of those antennas, and pass the General test.

    Liked by 1 person

    1. Woodman,

      I was there 07-10, with two deployments to Iraq.

      Every pair of my field boots are dark red- you’ll NEVER get it out. 🙂

      Aloha, Mahalo and Tropic Lightning!

      Like

  3. .weston.pecos.

    Their information says that the coax shield functions as the counterpoise. How much length of coax do you need to carry the output of the tuner to the matchbox thingie? I am assuming you need same length of coax as you are using for the antenna itself, 30 feet with the wire included with the antenna (total distance of 60 feet, with 30 feet of coax and then 30 feet of antenna), right? Or, can you use much less coax than that?

    Also, my radio (ICOM 756 Pro3) and LDG tuner are grounded, and the output goes through a lightening arrestor that results in grounding of the shield. Will that mess me up? In other words, should I only use this without the grounding?

    Thanks in advance for your thoughts on this. Ps. As it may already be clear, I’m thinking of using this as a base antenna. I’ve got a big dipole up there in the sky already but I like having lots of back up and options.

    Liked by 1 person

    1. The shield can function as a counterpoise, but there’s a terminal to attach one if you like. For the test I used a 25ft run of RG-8X.

      I really can’t say how the arrestor will change the performance, but I’d suspect that the biggest change will be an improvement of the signal to noise ratio.

      I think it’s an awesome option for a backup or a primary.

      Like

    2. Marshall

      Aloha Weston,

      In “instructions” say that you need 18 feet of coax to serve as a counterpoise. I attached an additional 16 inch piece of 24 gauge to the grounding terminal and it helps. I really need to run a proper ground out the window of the shack.

      I never read the instruction regarding the length of the coax, a friend clued me in when I mentioned my background noise.

      Give us a couple of weeks to build some more units and then place your order.

      Marshall
      EARC-HI Antenna group coordinator

      Liked by 1 person

  4. Chris

    The biggest problem with an end fed antenna (if it IS a problem for your installation) is that your rig is at one end of the antenna. That is a high voltage point, so you get lots of electric field – and possible “RF in the shack” problems. With some rigs and power levels, there is no problem. But if there is, some things can help. Ground (earth) the shield of the feed coax near the transformer box. Add a counter poise that’s longer than the connection coax. Or add a counterpoise from your radio, extending out away from the coax.

    Liked by 1 person

  5. Marshall

    My apologies to everyone trying to order one of these antennas, right now. We built a bunch of units based on past purchase rates and…….. Well Murphy showed up and depleted our normally adequate stock. We will get them back up on the website as soon as possible. And it has nothing to do with how well the surfing has been.

    I will leave a notice here when we have stock.

    Mahalo for your patience.

    Marshall
    Antenna Build Group coordinator – EARC-HI

    Liked by 1 person

  6. Pingback: Brushbeater: EARC-HI End-Fed HF Antenna | Outlander Systems

  7. Jørn

    I am aspiring and self taught RTO and new to HF, so really appreciate the tips and tricks offered. Because of a long term budget crunch, I’ll have to stay with the el’cheapo home brew methods. I’ve even resorted to using RG6, or RG59, 75ohm cable TV coax for HF, VHF and UHF. RG6=Rg8x and RG59 is less lossy than RG58. This is a huge cost savings technique. Got hundreds of feet for free with connectors. Because of the wide availability, it’s everywhere, it makes for a good field expedient option or everyday option. The impedance mismatch can be a non issue if the connecting cable is cut into whole half wave lengths. The result is that the bandwidth for the antenna should be the same as if using 50ohm cable. If not cut into whole half wave lengths, then the bandwidth is narrower. BTW, ye’ol rabbit ear TV antennas make for a cheap and easy to make, broad-banded, and horizontally or vertically polarized antennas that pack up small. Polarization makes a different. With one antenna listening to another antenna with the opposite polarization, the signal is harder to hear because it is attenuated by 20 to 28Dbd. A horizontally polarized yagi is harder to hear by vertically polarized antennas because the signal is attenuated 20+ Dbd, more than off setting the gain in the yagi, and the VHF signal passes through trees a bit better. This is helpful especially if using low power. I listen with both polarization as signals traveling further can refract, bounce and change polarization with distance. A hand held in the field is not always vertically polarized. Please excuse if I’ve gone waaaay off topic……

    Liked by 1 person

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