On Dec 10, 7:50*am, Cecil Moore wrote:
Fred PA0FVH wrote:
Is 5/8WL on 10meters a good height or 8 meter (22')?
What I want is a low take off angle on 20 and 30 meters with high efficiency
and an impedance which my remote ATU can handle.

Yes, you don't want to get much longer than 5/8WL on
10m and you don't want to get much shorter than 3/16WL
on 40m. 22 feet is a good compromise length. At my
previous QTH I used a 22' monopole with the feedpoint
elevated at 22' with four 22' radials sloping down
at 45 degrees (also used as guy wires) and fed with
an SG-230. It worked like a charm for transmitting -
noisy on receive. Here's some information from
simulations:

22' Monopole with 22' elevated sloping radials:

Band: Gain: Take Off Angle: Feedpoint: ~Tuner Loss
40m: 0.53 dBi: 22 deg: * 24-j229 ohms: 0.9 dB
30m: 0.94 dBi: 19 deg: * *46-j31 ohms: 0.2 dB
20m: 1.47 dBi: 16 deg: *128+j233 ohms: 0.1 dB
17m: 1.91 dBi: 14 deg: *556+j583 ohms: 0.2 dB
15m: 2.47 dBi: 12 deg: 1315-j372 ohms: 0.3 dB
12m: 3.40 dBi: 13 deg: *373-j560 ohms: 0.3 dB
10m: 4.21 dBi: 11 deg: *885-j290 ohms: 0.2 dB
--
73, Cecil *http://www.w5dxp.com

Experimenting with a too long antenna on 10M can be fun. I did a 1.25
wl antenna and got some interesting results during band openings. You
get to talk to where everyone else isnt. I felt like the band had
opened just for me. Of course this isnt the norm.

Jimmie