I have uploaded a short video of my backyard and am going to try to do the HFTA
analysis this afternoon. I am getting more and more inclined to install my
tower in the very back of my property. It’ll be interesting to see what the
terrain analysis comes up with!
Thanks, here’s the video if anybody cares to view it, although I don’t think
it’d be too much help. It’s in HD, so adjust youtube accordingly!
https://youtu.be/6LU1qh97BFg
Howard, W1HBO
From: Grant Saviers
Sent: Tuesday, May 23, 2017 11:07 AM
To: Howard Ochs
Subject: Re: [TowerTalk] Tower location and house noise
Howard,
I think you might benefit from HFTA terrain analysis, CD in the ARRL
antenna book. You can get the custom DEM file for your specific lat-lon
from Stu K6TU at K6TU.net. A terrific free service from Stu since the
gov't instructions are usually gibberish.
You don't mention the azimuth of the terrain fall off, but locating the
tower close to it will increase the effective height of the antenna in
that direction. With a 55' tower this can make a significant difference
in performance. So you might try an HFTA L-L close to the shack and one
near the fall off. Off course if the fall off is in a useless direction
then there is little benefit. The location choice is dependent on your
operating goals and the most difficult azimuth to achieve those QSOs.
For fine grain location choices you will need a good GPS or google map
to get the L-Ls to enough significant digits.
As a strategy you should be able to fix/control all noises sources in
your home/shack. It's the ones you can't control to maximize their
distances to the tower.
Trees don't affect HF very much until 10m and higher. Significantly at
2m and up.
With a 150' run to the tower, investing in upgraded coax is a good idea,
LMR600 or LDF4-50 or best would be AVA5-50/LDF5-50 7/8" hardline. With
a crank up, you can't do much better than Buryflex for the run up the
tower and the rotator loop. So you might end up with more than 225' of
coax, so calculate the loss for each band and think about how much lower
coax loss costs vs the rest of the investment per db gained with the
tower and beams.
Hope this is helpful,
Grant KZ1W
On 5/23/2017 6:18 AM, Howard Ochs wrote:
> Hi Fellas,
>
> I am soon to begin my installation of a tx-455 in my backyard and this
> topic is making me re-think my own tower's location. I thought I had my
> chosen spot, which is the highest point in my backyard, and only 20' from
> my shack.
>
> However, if I were to locate it to the very back of my property,
> approximately 150' from my house, it'd be that much further from all my
> sources of noise (homes, powerlines, etc.) since it's woods and finally, a
> river. In that placement, it'd be next to our small pond and next to a
> fairly steep slope dropping down into the woods and river. As well, at
> this location, it would lose 20' in height and be near some fairly tall
> trees, although not among them.
>
> What to do? I may just take a video today, upload it and get some opinions
> from those of you with much more experience!
>
> Howard, W1HBO
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