Multi-band end fed antenna

[Prerunner1982]

Built an 80m end fed half wave antenna over the holiday weekend that covers 8 bands 10m-80m, built the 49:1 unun transformer as well. It was a fun little project and I can't wait to set it up and do some field ops. At 134'+ I will need a lot of room to set up. This is the 3rd HF antenna I have built and it's nice to have options, which include a 20m/40m fan dipole and a 6/10/15/20/40m linked dipole.
Set it up as an inverted V as it would be the easiest to set up especially portable.
Started out with a counterpoise and no choke, tried counterpoise and choke, and finally settled on no counterpoise and a choke as I got the best numbers across all of the bands with that configuration. I tried it horizontal as well and saw an improvement on 80m and 30m but other bands got worse.

SWR across each band
80m (3.5MHz - 4.0MHz): 1.8-2.0
40m (7.0MHz - 7.3MHz): 1.2-1.8
30m (10.1MHz - 10.15MHz): 2.4-2.3 (don't plan on using, but could with internal tuner)
20m (14.0MHz - 14.35MHz): 1.6-1.2 (14.2-14.32 was 1.1)
17m (18.068MHz - 18.168MHz): 1.5-1.6
15m (21.0MHz - 21.45MHz): 2.1-1.1 (drops quickly as it is at 1.1 by 21.4MHz)
12m (24.89MHz - 24.99Mhz): 1.6-1.4
10m (28.0MHz - 29.7MHz): 3.8-2.4 (28.63-28.85 was 1.7, 28.5-29.05 was at or below 2)

Not all that happy with 10m but it's usable and I can use the internal tuner to bring it down. My radio also has two antenna outputs so I could always put up my linked dipole for 10m if I wanted.

 

[M Rose]

Built an 80m end fed half wave antenna over the holiday weekend that covers 8 bands 10m-80m, built the 49:1 unun transformer as well. It was a fun little project and I can't wait to set it up and do some field ops. At 134'+ I will need a lot of room to set up. This is the 3rd HF antenna I have built and it's nice to have options, which include a 20m/40m fan dipole and a 6/10/15/20/40m linked dipole.
Set it up as an inverted V as it would be the easiest to set up especially portable.
Started out with a counterpoise and no choke, tried counterpoise and choke, and finally settled on no counterpoise and a choke as I got the best numbers across all of the bands with that configuration. I tried it horizontal as well and saw an improvement on 80m and 30m but other bands got worse.

SWR across each band
80m (3.5MHz - 4.0MHz): 1.8-2.0
40m (7.0MHz - 7.3MHz): 1.2-1.8
30m (10.1MHz - 10.15MHz): 2.4-2.3 (don't plan on using, but could with internal tuner)
20m (14.0MHz - 14.35MHz): 1.6-1.2 (14.2-14.32 was 1.1)
17m (18.068MHz - 18.168MHz): 1.5-1.6
15m (21.0MHz - 21.45MHz): 2.1-1.1 (drops quickly as it is at 1.1 by 21.4MHz)
12m (24.89MHz - 24.99Mhz): 1.6-1.4
10m (28.0MHz - 29.7MHz): 3.8-2.4 (28.63-28.85 was 1.7, 28.5-29.05 was at or below 2)

Not all that happy with 10m but it's usable and I can use the internal tuner to bring it down. My radio also has two antenna outputs so I could always put up my linked dipole for 10m if I wanted.

I get best resaults with my EFHW set up as a sloper with the matching network about 5.5’ off the ground slopes to 60’ at the other end. Drops the noise a lot.

 

[Prerunner1982]

I should have tried it as a sloper, but one end will probably only be about 20'.

 

[M Rose]

Right now I have mine configured in an inverted lazy L... matching unit is at 4’ and strait up my flag pole 20’ then slopes to 40’ ... it s getting ok resaults. But it’s not cutting the QRM as well as the sloper configuration did... I just don’t have the room to run it as a full slope...

I’m trying my hand at a OCFD for 80/40, and if it works I will make a 40/20 as well which would give me all the bands.

 

[J.W.]

Looking forward to seeing what you come up with for a portable setup. 134' definitely takes some planning but those numbers look really good.

 

[Prerunner1982]

No adjustments made, just testing as I already had it set for Inverted V, not sure there were really any adjustments to be made.
Inverted L.... more of an inverted sloping L.

Compared to Inverted V
80m: about the same
40m: Better, lowest SWR more in the middle of the band, actually in the SSB portion.
30m: slightly worse
20m: Better over all, lowest SWR moved closer to the middle of the band closer to the CW portion which I don't use as much but better for digital.
17m: same
15m: worse
12m: much worse
10m: about the same over all, but lowest SWR moved from the SSB portion of 10m up towards the FM portion.

Sloper:
Compared to Inverted V
80m: about the same
40m: same
30m: same
20m: shifted lowest SWR to CW portion of the band
17m: slightly worse
15m: slightly worse
12m: worse
10m: over all about the same but the lowest SWR was 2.2 and that was a very narrow.

 

[M Rose]

Thank you Jon for your resaults. I’m currently working on a shortened 80m EFHW that is ~70’ long. My analyzer is giving me some funky readings so a friend is coming over tomorrow so we can tune the antenna... this one will be set up in a “L” configuration for the first round of testing, then I am going to try my hand at setting it up in Inverted “L” and inverted “V” configurations to test propagation.