The current conditions on the 10m band are fantastic… and because of the challenge, SOTA is also very active. Some activators are thinking about antennas exclusively for 10m.
Herbert OE9HRV is currently very successful with his 100 watts into his hentenna. He documented it here … The japanese “miracle wire”
I’ve always been a fan of loop antennas (Quad, Loop, Oblong,…) - and was therefore looking for something SOTA friendly. It should be cheap and not so bulky.
When I compared the loop antennas, which you can do very well on the DK7ZB side, I found the Oblong to be the best compromise:
You can build it for a 50 ohm feed.
It has a good bandwidth of 600 kHz with an SWR well below 2
It has a gain of approx. 2 dBd (Hentenna approx. 3 dBd)
It is easy to set up with my DX-Wire Minimast (in addition to the 40/20/15/10m EFHW)
The construction costs are less than 10 euros and the construction time is 2 hours
I made it with plastic pipes for electrical installations. They are light, divisible and stable enough. The wire loop has approximately 1 lambda (horizontal 1.82 m - vertical 3.79 m).
In a direct comparison, the EFHW is slightly better within shorter distances in Europe. But as soon as flat radiation is important (DX), the Oblong shows its advantages. It can be up to 2 S levels better against the EFHW.
Overall, it is a quieter antenna that picks up less interference.
Comparison test by constantly replugging the BNC connector … at windy DM/BW-018
Looks good Armin. When I was looking for a 10m antenna a couple of years ago, I considered this design but decided against it. I wasn’t confident it would remaim stable on a windy summit. How do you stop the plastic pipes from twisting?
It depends upon the summit - I have a couple around here with a little space and I can get this up and operational as quickly as I can my linked dipole.
The 10m Oblong with an assumed feed point height of 3m looks good in EZNEC (plot below).
Also shown for comparison are the (weighty) Hentenna from OE9HRV and my 10.90 m multi-band inv-L antenna (designed exclusively for the needs of Bruno, HB9CBR).
I can confirm that Herbert OE9HRV has one of strongest signals from Europe that I hear in the southern USA. He also typically runs 100W with an FT-891, but he has been armchair copy when I can’t hear many of the other activators (including those on CW) on the air at the same time. I don’t think I would lug all that gear up a mountain, but kudos to him for doing it.
