[SEDXC] tree climber - wire antenna installation help
Mike Greenway
K4PI at BELLSOUTH.NET
Tue Oct 28 17:13:08 EDT 2014
HI Frank, couple of comments. Of course raising it some will help but don’t think it will make it to the VK9XSP group. With a 4 ele yagi at 90 ft they have been mostly 559 or less. I have worked them on several bands but it took some doing and the window of opportunity is very narrow for them.. On 10 M around 2330 a 30 minutes either side. Also 12 M around 1230 long path.
I think it will take something with some gain at some height. We have had super conditions for the high bands the past week also so not going to get much better propagation. VK9AN who was on Christmas Is. a few weeks ago had a better signal in here on 30,40 and 20 CW. Good luck anyway.
GL 73 Mike K4PI
From: Frank T Brady
Sent: Tuesday, October 28, 2014 12:42 PM
To: SEDXC
Subject: [SEDXC] tree climber - wire antenna installation help
UPDATE:
Again, thanks to SEDXC and all of the help offers I received. The 135'
doublet is up - Robert Miller was reasonable and fast. I'm still
cleaning up from all the necessary tree trimming. It turned out that
the longest route for the flattop was about 98', so I had to vertically
droop 20' of wire at each end to accommodate the 135' antenna.
IMPLEMENTATION:
After several frustrating weeks trimming the 600 ohm feedline length
without being able to tune all 80 through 10 bands, I was forced to
resurrect a system of six relays I once used to physically insert
segment(s) of feedline to add up to the exact feedline length for each
band. I originally built it for 450 ohm feedlines. Converting it from
narrow 450 ohm window line to the wide spaced 600 ohm line took up so
much space I had to put it in the garage and remotely control the relays
from the 2nd floor shack. It now works like a charm!
QUESTION:
I haven't been able to hear even a hint of signal from the VK9XSP
Christmas Island expedition. Could part of the problem be that the
antenna is only up 30'? I can get Robert to raise it another 20' with
significant additional tree trimming. Before I go to the trouble, does
anyone know from their own experience that raising a wire antenna from
30' to 50' really helps? I'm also aware of the complicated multiple
lobe radiation patterns for multi-band wire antennas. Maybe I have a
deep null at the VK9XSP bearing - I'll never know.
73,
Frank W0ECS
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