I am a beginner with not much experience in HF. My shack consists of a Xiegu G90 connected with 20ft of RG-8x to an MFJ 1982 end fed half wave antenna. There is a small coil of coax next to the matching transformer box. The radiating element is suspended in an inverted V configuration with the midpoint around 30ft above the ground. The unun is connected to the eave of my house around 9 feet in the air. There is also a 10ft counterpoise connected to the matching unit. My problem is that I am only hearing the very strongest signals on some HF bands, On the other bands, I am hearing nothing at all! I know that the manual says to leave the matching unit near the ground, but performance is maybe even worse when I do that. The SWR on all the bands it covers is very good, never exceeding 2:1. I was wondering if someone could possibly shed some light on my predicament. Thank you all in advance, Levi, WH6GBR
First, what bands are you listening to? You should hear activity on roughly 20m – 40m during the day (and 15m sometimes), and 40m – 160m at night. This is close to the bottom of the sunspot cycle, so signals are often fairly weak, but there should be a few loud stations on 20m and 40m.
Your antenna would do better to be higher, but it's high enough for starters.
Your biggest problem is most likely that it's end-fed, and that it has such a tiny counterpoise. Marketing claims aside, end-fed antennas are finicky and difficult to feed efficiently. Also a transmitter trying to transmit into a high-impedance load needs an efficient RF ground to "push against", and your counterpoise, a single wire a fraction of a wavelength long, doesn't offer much of an RF ground. Your coax to the feedline would radiate if you transmitted, and you would probably have RF in the shack, which causes all sorts of weird problems with other electronics nearby. Poor transmit antennas almost always make poor receive antennas (there are exceptions), because if power doesn't get out efficiently then it doesn't get in efficiently either.
If you can, try putting up a dipole antenna, or a variation of a dipole antenna that's fed in or near the middle, with a good balun. Raising the coax to the center of the antenna might be tricky, and you might need an antenna tuner to get a good SWR, and you might not have very many bands; but you'll be amazed how much better it works than your EFHW, and you won't need a counterpoise for it.