EFHW working great!

[N4GIX]

I finally managed to get help getting my new, home built EFHW antenna installed. Much to my surprise, it it working fine without any tuning required. My RigExpert shows <1.5:1 on 40m, and <1.2 on 20m.

It has a 49:1 unun, and the wire is just a bit over 64' after folding back 2'.

Because of some broken fiberglass mast sections one end was only able to be raised to ~25' and the other end is still at ~42'.

 

[popnokick]

So you have an EFHW sloper.... perfectly legitimate configuration. GREAT that it works so well on 20 and 40. And you may have answered some of these questions in previous threads, but since you started a new one some of us may not know all the details of your home-brew EFHW (End-Fed HalfWave) antenna. So here goes:
- What did you use for the balun / un-un? Did you build it yourself or buy it?
- What feed line and how long is it?
- Any RF counterpoise? (Should NOT be necessary at all per recommended configuration... but had to ask.)
- What rig are you using with it?
- What power levels are you running?
- No tuner? But do you have one? External or the tuner in the rig?
- Have you tried it on bands other than 20 and 40?
- Do you operate FT8?

 

[N4GIX]

So you have an EFHW sloper.... perfectly legitimate configuration. GREAT that it works so well on 20 and 40. And you may have answered some of these questions in previous threads, but since you started a new one some of us may not know all the details of your home-brew EFHW (End-Fed HalfWave) antenna. So here goes:
- What did you use for the balun / un-un? Did you build it yourself or buy it?
- What feed line and how long is it?
- Any RF counterpoise? (Should NOT be necessary at all per recommended configuration... but had to ask.)
- What rig are you using with it?
- What power levels are you running?
- No tuner? But do you have one? External or the tuner in the rig?
- Have you tried it on bands other than 20 and 40?
- Do you operate FT8?

I put this together using the "HF Kits" that the ARRL partnered with and is selling from the ARRL Store. Here is the assembled un-un that I hand wound carefully. It uses an Amidon FT240-43 Toroid and wound with 1.0mm copper winding wire.

I'm using a 50' RG8x feedline since that was what I was using with the G5RV-Jr. antenna and it is a temporary expedient. The rig is my IC-7300 at 100 watts. I do have an IT-100 autotuner to "fine tune" for lowest VSWR, but honestly given the already low VSWR on both 40m and 20m it really isn't necessary. I could simply use the IC-7300's built-in tuner!

This antenna design should work well on both 15m and 10m but I haven't had time to try those bands yetl

I have not yet tried FT8, but do plan to do so over the next few weeks. I'd like to get Winlink working as well since that is what our District's ARES group is getting set up. I also own a Xeigu G90 and GSOC controller with the 7" color display. I was recently gifted with a legacy Kenwood TS-520 which I need to try out.

 

[prcguy]

Thanks for posting! A single FT-240-43 core will handle up to about 400w SSB so you should never have a problem with a 100w radio. I have not seen the instructions for that specific kit but MyAntennas places a coil (5 turns of the antenna wire around a 2" dia form) 78" from the transformer. I believe the coil helps move the 10m resonant point down into the tech phone portion of the band. Or maybe something else.

You can also add about 133ft of wire and do 80 through 10m. If you tune for the same resonant points 40 through 10m then 80m will resonate way down around 3.55MHz. There is an easy mod to cut the 133ft wire in half, insert and insulator then bridge that with a 250pf high voltage cap, preferably a doorknob type. That will bring the resonant point up to cover 3.8 to 4.0Mhz without a tuner and will not affect any other band. The same coil 78" from the transformer would be used on the 133ft version.

The MyAntennas 133ft versions I have cover 80 (actually 75m), 40, 30, 20, 17, 15, 12 and 10m all without a tuner. A few of the bands like 30 and 17m are starting to get up around 2:1 VSWR but I just connect my 1200w amp with out any tuner and it just works on all bands.

I put this together using the "HF Kits" that the ARRL partnered with and is selling from the ARRL Store. Here is the assembled un-un that I hand wound carefully. It uses an Amidon FT240-43 Toroid and wound with 1.0mm copper winding wire.

I'm using a 50' RG8x feedline since that was what I was using with the G5RV-Jr. antenna and it is a temporary expedient. The rig is my IC-7300 at 100 watts. I do have an IT-100 autotuner to "fine tune" for lowest VSWR, but honestly given the already low VSWR on both 40m and 20m it really isn't necessary. I could simply use the IC-7300's built-in tuner!

This antenna design should work well on both 15m and 10m but I haven't had time to try those bands yetl

I have not yet tried FT8, but do plan to do so over the next few weeks. I'd like to get Winlink working as well since that is what our District's ARES group is getting set up. I also own a Xeigu G90 and GSOC controller with the 7" color display. I was recently gifted with a legacy Kenwood TS-520 which I need to try out.

View attachment 112005

 

[N4GIX]

You can also add about 133ft of wire and do 80 through 10m.

Unfortunately the lot my house is on is simply too small to accommodate such a length of wire. It is only 50'x100' at the property line. My fiberglass masts only will allow a max of ~73' pully to pully. Yes, I could drop about 30' additional length down the garage's fiberglass mast as leg of an inverted "L", but that's still too short for 80m...

Any vertical that requires ground radials is also not physically possible. My front yard is postage stamp sized, and neatly bi-sected by a concrete sidewalk. My "backyard" isn't much larger, but even worse the power service lines run diagonally across the space. I'm also surrounded on three sides by power lines! In short, it's noise floor hell!

 

[AK9R]

Unfortunately the lot my house is on is simply too small to accommodate such a length of wire. It is only 50'x100' at the property line.

My lot is 90 x 140. I have a 75m dipole running across the short side. Of course, the dipole elements have 90 degree bends in them. I have about 90 feet mounted as you normally would for a dipole with about 21 feet on each end going off at 90 degrees to the "main" elements.