Mounting the antenna half-wave dipole - Mounting method - influence on the signa

Hello colleagues, recently I decided to buy a scanner which is Uniden UBC69XLT-2.
I use it on the VHF band for the fire department.
I use the scanner on the antenna from the set, unfortunately it does not meet my expectations. I want to hear within 20-25km.
So in this regard I made a decent half wave dipole and put it in the PVC tube. Everything was going my way until it was knocked it was time to mount it on the roof. Well, I plan to mount it directly to the seatpost without any booms (attached). Cable routed through the center of the PVC pipe to the bottom. My question is whether I can do something like that at all ... Will there be any disturbance or whether the seatpost will not be disturbed. Oh, and I want to mount it at the end of the seatpost, which is about 20m above the ground.
I am asking for help and advice

PS: And does this PVC pipe harm to some extent negatively affect the signal?

because everywhere it is, it must be at least 80cm from the seatpost and everyone says something else. Please explain

Remember that the indicated antenna - directed and no gain (0db). The position of the antenna in relation to the mast and surrounding objects is very important. Removal from them must be at least 0.2 - 0.3 wavelength.

And I would like to add that I do not want to have some fancy and big antennas that would attract attention. It's just best to mount what I did just a matter of interference or will there be problems with reception ...?

D-ca plutonu wrote:

because everywhere it is, it must be at least 80cm from the seatpost and everyone says something else. Please explain

It is true that the dipole must be moved away from the mast by at least 50 cm.

Added after 2 [minutes]:

D-ca plutonu wrote:

And does this PVC pipe harm to some extent negatively affect the signal?

This pipe will not be in any way, and even better that there, because it will protect the dipole from rain, it will not rust.

You can only get the correct answer to your question yourself. Only you are in the real place where the antenna will be placed and you can evaluate all obstacles to reception. For a colleague from the forum, your question - a fortune-telling on coffee sediment.

Well, I understand, but that's why I'm asking what could be an obstacle ... Will the seatpost mounted on the roof have a bad effect on the quality of the reception signal? will it interfere. The seatposts are made of a thick steel tube

D-ca plutonu wrote:

Will the roof mounted seatpost adversely affect the reception signal quality? will it interfere. The seatposts are made of a thick steel tube

The mast will obstruct the antenna from working properly.
Dipol "likes" height and empty space in the eye of himself.

In fact, if a colleague wrote at least 50 cm, what about the arm, extension arm. It has to hold on to something. If I was made of aluminum or a steel tube, it is also close to the dipstick. I present a picture found on the network here is a wire mounted and it can also interfere with you?

D-ca plutonu wrote:

I present a picture found on the network here is a wire mounted and it can also interfere with you?

Not this "wire" does not interfere with the dipole than the masts.

Rezystor240 wrote:

D-ca plutonu wrote:

I present a picture found on the network here is a wire mounted and it can also interfere with you?

Not this "wire" does not interfere with the dipole than the masts.

I do not understand the answer

The antenna is at the distance of the mast from the mast and the mast does not affect the antenna as much as if the antenna was directly attached to the mast.

Okay, what about the steel wire?

D-ca plutonu wrote:

Okay, what about the steel wire?

Maybe just mount a dipole on the roof as I told you and as you describe, you will see a difference, and a significant one.

And pro, after building the dipole, I made it of 25mm copper tubes, but it is not quite stable. So I can stiffen it by inserting a wooden stick, for example from a brush, into the center of the pipes along the entire length?

D-ca plutonu wrote:

And pro, after building the dipole, I made it of 25mm copper tubes, but it is not quite stable. So I can stiffen it by inserting a wooden stick, for example from a brush, into the center of the pipes along the entire length?

You can stiffen it with any insulator.
Remember about the 2cm gap between the heater and the counterweight.

Thanks for the answer. And I wrote on another forum, they said that the wood cannot go through the middle because it will be bad to pick up ...?

Added after 6 [minutes]:

And can I lead the antenna downwards, from the bottom of the dipole? (dipole in pvc tube)
Coaxial cable will not be in the way? Should I make a buttonhole and release in the middle?

D-ca plutonu wrote:

zieki for the answer. And I wrote on another forum, they said that the wood cannot go through the center because it will be bad to pick up ...?

And yes and no, wood may detune the antenna due to moisture, but let's not exaggerate, the receiving antenna is not transmitting, so it does not have to be perfectly tuned.

D-ca plutonu wrote:

And can I lead the antenna downwards, from the bottom of the dipole? (dipole in pvc tube)
Coaxial cable will not be in the way? Should I make a buttonhole and release in the middle?

So you do `` your own way '' - it won't work or it will be very clunky.

D-ca plutonu wrote:

And I wrote on another forum

Link to this OTHER FORUM

I plan to do something like the attachment. please give feedback.
PS: I know I realize that after a while the wooden stick will be useless.


Added on 22 Jan 2017 21:38:41
the antenna will be about 20m above the ground

Moderated By c2h5oh:

Do not post under the post. Use the "change" function.
I merged the posts.