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Author Topic: Antenna hight  (Read 5341 times)

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tobydude2

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Antenna hight
« on: February 23, 2019, 06:43:46 PM »
Hi.
Have a Radarbox and are sharing traffick.

Question:
How longer range will I get if I increase the antenna length with 2 meter?
There is a mountain here that block the antenna.
Is there any point in increase with 2 m?

https://www.radarbox24.com/stations/PGANRB500195



Runway 31

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Re: Antenna hight
« Reply #1 on: February 23, 2019, 07:27:03 PM »
I presume your mountains block to the north.  The 2 meters would probably make some difference but don't expect to much as your coverage in the other directions is very good.  If you can get it higher without much problem, go ahead.

Alan

abcd567

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Re: Antenna hight
« Reply #2 on: February 23, 2019, 09:33:23 PM »
Use the method described in the post linked below.
Prepare two plots:
(1) Using current antenna height
(2) Using current antenna height + 2 meters

Comparing the two plots will give you an insight.

    
What is the Maximum Range I can Get?


.
« Last Edit: February 23, 2019, 09:35:08 PM by abcd567 »

tobydude2

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Re: Antenna hight
« Reply #3 on: February 24, 2019, 06:12:23 AM »
I presume your mountains block to the north. 

Alan

Yes, mountains are to the north, as the coverage map shows.
Antenna already a bit high for norwegian weather conditions. :)



« Last Edit: February 24, 2019, 08:20:09 AM by tobydude2 »

tobydude2

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Re: Antenna hight
« Reply #4 on: February 24, 2019, 06:13:55 AM »
Use the method described in the post linked below.
Prepare two plots:
(1) Using current antenna height
(2) Using current antenna height + 2 meters

Comparing the two plots will give you an insight.

    
What is the Maximum Range I can Get?


.

Thanks. Will look into it ans see if it is any point making it longer. :)

tobydude2

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Re: Antenna hight
« Reply #5 on: February 24, 2019, 06:33:56 AM »
Use the method described in the post linked below.
Prepare two plots:
(1) Using current antenna height
(2) Using current antenna height + 2 meters

Comparing the two plots will give you an insight.
What is the Maximum Range I can Get?


.

Unfortunately  it does not cover my erea.

« Last Edit: February 24, 2019, 06:36:39 AM by tobydude2 »

wiedehopf

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Re: Antenna hight
« Reply #6 on: February 24, 2019, 01:20:16 PM »
Let's say your obstacle is 1 km away.

Because of the obstacle your current range in that direction is 100 km for aircraft flying at 10 000 m

That means the obstacle is 10 000 m / (100 km / 1 km) = 100 m higher than you.
Now if you increase your antenna height by 2 m it is 98 m higher than your.

Now your range is 102 km.

That calculation ignores curvature of the earth but it should give you a rough idea in what ballpark any improvements might be.

If you have obstacles close in antenna height will make a much bigger difference. (Or if it is already very flat around you)

tobydude2

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Re: Antenna hight
« Reply #7 on: February 24, 2019, 04:55:15 PM »


That calculation ignores curvature of the earth but it should give you a rough idea in what ballpark any improvements might be.

If you have obstacles close in antenna height will make a much bigger difference. (Or if it is already very flat around you)

Thank you.
Thas usful to know. Will calculate...

abcd567

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Re: Antenna hight
« Reply #8 on: February 24, 2019, 09:15:20 PM »
tobydude2

It is too bad that the heywhatsthat site does not cover your area. The heywhatsthat site is a very handy and fairly accurate site.

You can still calculate using the formula given in this sketch which I have drawn couple of years ago.
This is based on assumption that area around you is level ground, and not hills.

The image is very wide. Scroll right to see it in full

« Last Edit: February 24, 2019, 09:17:15 PM by abcd567 »

tobydude2

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Re: Antenna hight
« Reply #9 on: February 25, 2019, 06:20:18 AM »
Hi.
Yes, massage from The heywhatsthat say: "Invalid Latitude. (my latitude, 68N) We currently cover latitude
60N to 54S and most of Alaska".

Thanks for the formula. Will look into it.
I´v tried heywhatsthat for an erea south in norway, just to see how much longer range 2m antenna increase  gives.
Its not much. :)

« Last Edit: February 25, 2019, 06:27:02 AM by tobydude2 »

abcd567

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Re: Antenna hight
« Reply #10 on: February 25, 2019, 06:50:38 AM »
I´v tried heywhatsthat for an erea south in norway, just to see how much longer range 2m antenna increase  gives.
Its not much. :)

That is expected with a level terrain.

With hills around, the improvement will be more but still not much.

With large trees or houses around the improvement will be much more, and if the antenna is raised above the height of the tall trees & buildings, improvement will be really great. Some years ago I have made a sketch to demostrate this. It is attached below.

The image is very wide. Scroll right to see full image




tobydude2

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Re: Antenna hight
« Reply #11 on: February 25, 2019, 07:32:53 AM »
I have the antenna mounted on a pole, to get over the nearest rooftops and trees.
Its the mountains in the nort, that are det "issue". :)



Mountains north