Ham Radio - The doublet vs EFHW noise rejection comparison.

Have you tried the efhw with a common mode choke?

The 80m doublet is the king of antennas. The design has stood the test of time for good reason - it's fantastic. I have used the same one for over a decade and love it. Thanks for sharing !

After literally decades of trying just about every common HF antenna design there is I too have settled on the doublet....it's GREAT...love it! Mine is 140', fed with homebrew ladder line and ATR-30 tuner. I found that it tunes everywhere, including 160m. Over several months of testing it consistently beat my OCF 80m coax-fed dipole so I took that antenna down. Forget all the rest, the doublet is far and away the best.

I only have a small manual tuner (MFJ-902), but this has inspired me to finally learn how to use that tuner so that I can try out a doublet.

Hi. I decided to build a 80m doublet in Sept after your video and an Elmer swayed me. 63’ each leg with home brew ladder line all 14ga solid copper. Home brew 1:4 balun and 16” of RG-214 to my huge home brew roller tuner. True all band with QRO power levels and no RF in the shack ever. Quiet receive for my SDR interests as well. I’m sold on the 100 year old technology.

I see this a lot. Install that double exactly the same way as your EFHW and it will be just a noisy. It's all in the installation. Put the EFHW up like your doublet, use a common mode choke to make the playing field even. Put the choke at .05 wavelengths from the transformer. For 40m, measure about 2 meters from the xfmr, wind 8 turns of coax around a FT-240 31 mix core then run it in to the shack. You can even add chokes in series. Make another one using 43 mix and 4 turns for the higher bands. Just put it down a few inches from the fist one. Don't bother with commercial chokes. They are inferior to the above and cost several times more.

So glad to see you playing radio. There's nothing like building antennas out where room isn't a factor. Be well my friend!

Thanks for sharing. I heard a RF engineer explain that doublets are inherently better for low noise. Mainly because they are horizontally polarized. All the RF noise we from the other RVs is vertically polarized (according to the RF engineer all the noise that we have deal with as hams in an urban environment is typically vertical). In the little talk, he went on to say that you can run other antennas like an end fed for example. You can run that horizontally, but it is not horizontal polarization, it's still vertical. And thus you'll have more noise with end feds. Anyhow, I have good luck with a doublet fed with ladder line and I think it's still my favorite antenna. And literally the most simple. Two wires I cut from a spool of wire from Home Depot!

Thank you, really appreciate your effort to provide realtime A vs B comparison as well as the noise signature of a pure sine wave inverter.

Glad you're healthy again. Thanks for another great video.

I love my doublet! Multi band, quiet, inexpensive, simple and effective. EFHW probably has noise ground currents on coax shield.

I built doublet a couple years ago for field day and love it..It is my main antenna on field day..If you have a good tuner and some spare wire around get some window line and good 4:1 and get building you will love it!! :D

Nice comparison Kevin. Great to see another antenna related video. I've done both the 4:1 and the 1:1 current baluns on my doublets, and the 1:1 offers twice the choking impedance given the same quantity of ferrite. Just series the two cores that you paralleled. Most tuners have lower losses at higher impedances so using 4:1 can put the tuner into a lossier configuration. In most cases there is little difference between 4:1 and 1:1, but it makes an interesting experiment to try. Looking forward to the EFHW with common mode choke (and that will require a counterpoise). 73 de w6akb

Good video, great comparison of antennas. I’d love to run a doublet here and I’m a big fan of ladder line feeder. It’s hard for me to get the right feeder length though.

I too love my double Zepp (doublet) antenna for all the reasons cited, but there is one thing I noticed when I got a new radio, there is "RF in The Shack" and therefore everything, the radio and the tuner MUST be properly grounded. On many radios (especially tube types), the only problem is getting "bit" or "burned" by the RF, but with my new radio and tuner, the RF gets into the radio and somehow messes up the tuner too. After taking down the antenna and looking for problems at the termination and feed line (and finding none), it finally dawned on me that I had to ground the radio and the tuner per the bolts and nuts provided on them just for that. Proper grounding solved ALL the problems I was having including "RF in the shack."

I hear you on the health issues. Same here for 3 weeks in August. OK now to learn more about HAM radio.

I have a 102 foot doublet with a 4 to 1 balun...... After 20 years of various antennas this is by far my favorite...

Great Video! I have been tempted to put up a doublet as I have all the materials eg wire, 300 twinlead & 450 ladder line. But the guy's saga of using twisted-pair speaker wire intrigues me. So I'll start with a simple twisted-pair portable doublet.

I had very similar results. 60 ft EFHW vs 60 ft doublet, 600 ohm ladder line in to the my room, MFJ 986 roller tuner above my radio. With doublet noise level decreased about 1-3 S-units on different bands. And it may work anywhere with that tuner beginning from 3.5 Mhz (from 5 Mhz with good efficiency), and up to 51 Mhz. Of course, above 21 Mhz the diagram might be some strange, funny and unpredictable, but if I hear somebody, I work with somebody. 73!

Fantastic video. I had heard end fed antennas were more noise prone and looks like you've proven it. I have and end fed in my attic and it's pretty noisy, often S9+. I had a doublet that was bent into rectangle and it was fed with twinlead and it didn't pick up much noise, but did have an odd radiation pattern. I also use the LDG Z11 Pro tuner with a balun, but I use a switchable MFJ balun that can switch between 1:1 and 4:1. I use a barrel connector to connect it directly to the tuner without coax. I'm going to try a doublet gain, but this time in a dipole configuration and hope it will reduce my noise issues.