When using my EFHW antenna, I saw that it was -80dBm to -90dBm. So, I can barely make out anything they are saying. I read that you are supposed to have the antenna running north to south, and the lowest point should be half a wavelength above ground. I did all those things, but I am still receiving -80dBm. Should I make the antenna higher? One end is sticking out of a window and I hung the other end up a tree (what else am I supposed to use?) Or am I wrong and it is supposed to go east to west? Yes, I have low SNR. I am using a coax for the feedline. How do you add a counterpoise? I'm using a SWR meter and trimming the antenna until I reach 1:1. The feedline is surprisingly skinny, is that one of the contributors to the problem? Here is the link to it. It's something like ~3 mm? I want to know why I am having poor reception so I can fix it.

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    $\begingroup$ is low power the problem, or low SNR? If it's just low power, adding an LNA would solve the issue. $\endgroup$ Apr 6 at 15:05

3 Answers 3


All end-fed antennas are notoriously noisy and will pick up any nearby man-made electrical noise. I don’t know what you read, but you must find another credible source; they dunno chit. You did not mention two things: what you are using for a counterpoise and choke.

Telling us you ran it out the window to a tree tells me you likely do not have a planned counterpoise or any chokes. You are guaranteed to generate a lot of noise with lots of RF in the shack. Your coax is part of the antenna radiating and Receiving. Let’s see if we can get you going in the right direction.

An EFHW antenna is an oxymoron; it is an extremely off-center fed dipole, and you treat it as such or as a vertical antenna with a few caveats. First up is the counterpoise, the short side of the dipole. The counterpoise length depends on the lowest band the EFHW operates on. Counterpoise length = .05 WL, or 13 feet on an 80/40/20/10. If you fail to provide a counterpoise, the antenna will use your coax shield to your radio and provide you with RF in the shack and all the fun that comes with it, including RFI.

Second, you must use a Maxi-Choke outside to block the common-mode current and prevent it from entering the shack. You place the choke 13 feet from your EFHW transformer. Sound familiar? You will now have two tuned parallel counterpoises with 40 dB of more common-mode resistance, preventing your coax from radiating and picking up noise inside the shack.

Third, check your EFHW transformer and ensure it has a DC Ground—measure for short circuit between the center conductor and shield. That will discharge the static noise you are hearing. Some of the transformers on the market have isolated primary-secondary. That allows static buildup on the antenna to be discharged as noise in your radio.

Fourth, get the antenna as far away from your house and anything electrical as possible. It is endfed, unbalanced, and has high impedance, making it prone to picking up electrical noise.

Fith Antenna Configuration: If in quiet RF areas, ENHW can be configured vertically to yield an omni pattern. It would help if you found a tree or tower high enough to lift the antenna and counterpoise off the ground.

Most likely, you will use one of the many dipole configurations. To answer your question, you orient the antenna in the direction of interest. If you want to cover E/W of your location, you orient the antenna N/S. Ideally, you would like to elevate both ends of the antenna to half the wavelength of the lowest operating frequency. That would require at least two 135-foot tall structures about 150 feet apart. Get both ends as high as you can. Other dipole configurations include Sloper (kind of what you are doing now) and Inverted V.


Check your antenna matching transformer. Orientation and height will make a small difference but not many dB.

I happen to have measured my end-fed antenna this week... The noise level was higher than that, maybe -70 dBm across the band. Medium wave stations were over -30 dBm.

Mine is 20 metres long, with a home-made transformer. I tested both the transformer and then antenna carefully.

One possible data point is that some cheap Amazon baluns are wound or connected incorrectly and just don't do what they claim. (Sample of two). The 49:1 unun is more difficult to get right.

If you don't already have one, get a NanoVNA and test everything step by step.


The direction should not make all the signals low level. Running out the window and up a tree is a common arrangement and you should receive plenty of signals.

At this point, we need to know more. What radio are you using? What frequency are you listening to?

If you can just barely hear the voices it makes me think it is more likely that you have a feedline or radio problem than an antenna problem pre se.

More info please!


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