Member III
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.
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.
Attachments
-
123.6 KB Views: 41
-
128.6 KB Views: 24