[TowerTalk] Tower location and house noise

Tue May 23 18:27:22 EDT 2017

Chuck and Bob, thanks for your thoughts.  I sure am glad I have plenty of time to weigh all of this information!  There is plenty to think about, most of which I hadn’t before I asked here.  All good points.  It’s time for me to start jotting down a pro/con list.

Thanks to everyone that replied.  All of this info really is invaluable!

Howard, W1HBO

From: Bob Shohet, KQ2M
Sent: Tuesday, May 23, 2017 4:24 PM
To: Chuck Dietz; howardbochs at gmail.com
Cc: TowerTalk at contesting.com
Subject: Re: [TowerTalk] Tower location and house noise

Whether or not the the back of the lot should be the siting choice will depend on many factors.  Terrain Analysis is essential and it should be done with the most utilized antenna beam headings in mind.  Most qth’s are a compromise between different directions at different heights and different wave angles.  That is, if EU is most important for contest scores (or Dxing) then you should make that the priority for maximum wave angle coverage for whatever bands you are going to use.  Back of the lot may NOT be best, or some other location on the lot may be better.  What is best for the antenna(s) may not be best for noise and/or other factors.  It is not a simple process if you take everything into account and do it properly.  Ideally you should look at several different spots and run the terrain analysis for different directions and different antenna height configurations on different bands and then sit with it for a few weeks while you digest it all.  Since you are not going to move the tower once you dig the hole and put it up, your best bet is to do a slow and thorough  analysis and then “sit with it”.  Many future years of performance will depend on a few weeks of analysis done properly now, so take your time.  You will be well rewarded for your diligence and patience. 

Unless there are other important considerations, I would avoid the back for several reasons.  

1) You will get lower angle lobes by putting the tower up near the top of the property, than you will if you put it lower down.  You will hear better and stations will hear you better.  Almost like having an amp on txmit and preamp on rcv but without actually using one.   :-)

2) You don’t want the property draining down into your tower base, not do you want to be doing antenna work on a slippery downhill slope on the land.

3) If you hang wire antennas off the tower, you will want them as high up as possible, not have their height compromised by staring up at the top of a hill.

4) If the tower is in the front of your house and EU is in front of your tower, then you will be pointing away from any house noise sources and your antenna pattern will help to null them out, rather than if your antennas are pointing at the house.  Of course it is also important to know whether or not your tower and antennas will be very close to your neighbors.  Remember the FCC calculations that we are supposed to perform for our stations and antennas. 

5) The way to find out if you have any neighbor noise sources is to make a few wire simple directional wire antennas for each band and put them up in the trees and operate that way for a few weeks – months.  You will quickly find out where the noise sources are and that can inform your tower citing strategy.

You should also realize that all noise sources are worse on certain bands and better on others and this includes high voltage power lines on right-of-ways from the power companies.  Some potential noise sources that we intuitively fear turn out to be minor or nothing at all whereas other things that we discount or are not even aware of turn out to be disastrous – like a leaky power line insulator that could be easily noticed  with a directional spotting antenna.

There are more factors of course, but these are most of the major ones. 

I performed all of these steps before putting up my towers in 1998.  It saved me years of needless grief and regrets.  And in 1994 before I even bought the property, I drove up with a radio and a dipole and tested the noise and qrn at this location just to make sure that before I got serious about the house and property, I knew that it was going to be a good location. 

73 and GL!

Bob  KQ2M

From: Chuck Dietz 
Sent: Tuesday, May 23, 2017 1:28 PM
To: howardbochs at gmail.com 
Cc: TowerTalk at contesting.com 
Subject: Re: [TowerTalk] Tower location and house noise

Definitely the back of the lot. More than just cutting down noise, it will
help prevent RF getting into computers.

Chuck W5PR

On Tue, May 23, 2017 at 11:04 AM, <howardbochs at gmail.com> wrote:

> 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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