vertical antenna near tree

Status
Not open for further replies.

mrscanner2008

Member
Premium Subscriber
Joined
Jun 21, 2008
Messages
331
Location
Canada
Hi

I`m new to ham radio and a plan to install a vertical antenna (5BTV) by a tree and wonder if this will attenuate the reception ?

In my city we have strict rules for ham radio antenna and want to hide my antenna in my tree.

photo of the tree in attachment.
 

Attachments

  • arbre.jpg
    arbre.jpg
    134.6 KB · Views: 4,526

Spud

Member
Joined
Jul 9, 2005
Messages
156
Location
Fort Collins, CO
5BTV install

I have operated in the past with a ground mounted vertical installed like you are proposing (mounted fairly close to the trunk of a tree and extending up through the limbs above).
The only issue was changes in the tuning caused by rain or snow on the tree and ground.
Keep in mind that the 5BTV operated without ground radials (with only a ground rod for a counterpoise) will have compromised performance.

From your picture, the metal fence would be more of a concern than the tree.
It will alter the tuning of the antenna and some RF will be coupled onto the fence due to its close proximity to the vertical antenna. Coupling RF onto the fence would not present a hazard to persons but the fence having lousy bonding between adjacent mental parts might cause some of the RF to be re-radiated as spurious or harmonic emissions that are not desirable (possibly creating RF interference to other equipment close to your location).

With any antenna installation, actual results usually do not exactly match theory or assumptions.
Best to go forward, try what you are proposing and see how well it works, especially if your location does not offer any other options.

73,

The Spud
 

mrscanner2008

Member
Premium Subscriber
Joined
Jun 21, 2008
Messages
331
Location
Canada
Thanks for the reply Spud.

I operate my vertical with radials so i have good performance for now.

How far from the fence do i have to put my antenna?

Like you said, i will try and see if i got good result.

73
 

LtDoc

Member
Joined
Dec 4, 2006
Messages
2,145
Location
Oklahoma
Can it be done? Yes. Will it work? It will work better than no antenna, but I wouldn't make a guess about how 'well' it will work.
There are going to be a few 'catches' to doing the tree/antenna thingy, especially since it's so close to your house and your neighbor's. Expect there to be some interference problems. Not from spurious emissions, but from electrical things being so close to a strong RF source.
Another thing is that keeping an antenna 'tuned' is subject to what's around that antenna, and if and how those surrounding objects change for whatever reason. Trees go through seasonal changes and so will the antenna's tuning.
I guess the best option is to try it and see what happens. Probably won't be the bestest thing in the world, but it beats no antenna at all, right?
- 'Doc

(It all boils down to what's practical for you and the circumstances. Do what you can.)
 

reedeb

Member
Joined
Sep 14, 2006
Messages
849
Location
Dallas Texas
I don't know what band yu are using, IF it's 2 mtr or 70 cntmtr a dual band Ventanna my work better. [and will be hidden from nosey neighbors.]
 

mrscanner2008

Member
Premium Subscriber
Joined
Jun 21, 2008
Messages
331
Location
Canada
@reedeb: I'm using 80 to 6 meters bands. I already have an antenna for 2m and 70cm.

Another question by the way: here in my country we have lots of snow in the winter ( 4 to 6 feet of accumulation during winter) do you think that will cause problems if I install my vertical in the ground with radials (bottom of the vertical 4 inch above ground like the instruction said)???

I'm using a LDG AT-7000 antenna tuner with my Icom Ic-7000, do you think the tuner will compensate for the inconvenient of the installation?

thanks all for helping a new ham enthusiast .
 

LtDoc

Member
Joined
Dec 4, 2006
Messages
2,145
Location
Oklahoma
Will snow affect the antenna? Sure. No idea how much or in what way, but you can be sure that there will be some affect.
Will using a tuner (of whatever brand/model) 'compensate' for the less than 'perfect' antenna location? I would say it can make the antenna usable, but it won't compensate for it being less than ideal. I can't think of anything that would.
How can you know for sure? You can't without trying it. Sorry...
- 'Doc
 

SCPD

QRT
Joined
Feb 24, 2001
Messages
0
Location
Virginia
Snow is good

... Another question by the way: here in my country we have
lots of snow in the winter ( 4 to 6 feet of accumulation during winter) do you think that will cause problems if I install my vertical in the ground with radials (bottom of the vertical 4 inch above ground like the instruction said)??? ...

I've always had antennas play better when the ground mounted verticals are either covered with snow, or we have had a good soakiing rain.
 

NML-21

Member
Joined
Apr 14, 2009
Messages
31
Location
S. Portland, Maine
The tree would be of no concern. However, all that other metal stuff in your yard such as the bench, the swing, the chairs and even possibly the fence will definately attenuate your Hustler antenna.

When I initially installed my antenna, it was about 10 feet from an aluminum shed. I was having crazy attenuation issues. I tried several things and even went as far as having DX Engineering help me out. They had me send them several photo's of my antenna. They stated it was necessary to get it as far away from other metal objects as I could. I then re-mounted the antenna in my yard with as much distance from other metal objects. They helped me out so much, I went ahead a bought several accessories from them specially made for the 5BTV such as the 17M add on it.

I now talk DX all the time.
 

k9rzz

Member
Joined
Dec 12, 2005
Messages
3,162
Location
Milwaukee, WI
That little tree? Go for it, I wouldn't give it a second thought. Sure, anything in the antenna's field will affect it (SWR mostly), but will still work? I don't think you'll notice any problems. Like mentioned, build a killer ground system (including that fence) and you'll have a grin ear to ear. Tie a flag to the top and call it a flag pole.
 

Spud

Member
Joined
Jul 9, 2005
Messages
156
Location
Fort Collins, CO
Chain Link fence issues

The answer to your earlier question is: mount the vertical as far from the chain-link fence as you can without causing other problems (such as lack of concealment or it becoming an obstacle in the yard).

Do not connect to the fence for the initial install as it will likely cause additional changes to the tuning of the antenna and the metal parts of the fence are not electrically bonded to each other. These "dirty contacts" between the metal parts of the chain-link fence can act as diode connections and re-radiate RF energy at harmonic and spuroius frequency that can increase the interference caused by your transmitted signal. Mounting the antenna close to the fence will couple some of the RF onto the fence anyway but making a connection to it with your ground wire system will just increase the chance of unwanted effects.

Just put down as many ground radials as you can and use a good ground rod for lightning protection at the base of the vertical or at least before the feedline enters the house. You can always connect to the fence after the rest of the install is complete and see what changes occur with the RF output tuning and radiated energy. Check with neighbors and also pay attention to any other receiving equipment (radios, TV, etc) in your own house to see if interference issues are being made worse with the fence connection. If you have an adequate ground radial system, connecting to the fence will not provide any significant improvement to your transmission or reception.

73,

The Spud
 
Last edited:

k9rzz

Member
Joined
Dec 12, 2005
Messages
3,162
Location
Milwaukee, WI
That little tree and fence isn't going to do jack. What's it going to do, suck all the RF from the antenna? It's going to skew the pattern a bit but you'll still be able tune the antenna for low SWR, you're still going to get full power into it, and you're still going to work plenty of stations. Put down the best radial system you can, just as you would any vertical, and forget about it. Don't sweat the "what if's ".
 
Status
Not open for further replies.
Top