Sorry for the many questions.
Does anyone compare the 900MHz Antenna to 1090MHz Antenna?
I want to buy some new and i have some good results with an 900MHz Yagi Antenna from China.
Thank!
How could an antenna designed for 900MHz possibly perform anywhere near as well as one designed for 1090MHz at that frequency?
You may have achieved "good" results from a 900mhz antenna but I am confident you will better your reception with a dedicated 1090mhz unit.
Always remember the old adage-any receiver is only as good as its antenna and any antenna is only as good as the coaxial used in the installation.
Regards-
G.B.
sure an 900mhz Antenna from the China man cost 15GPB and an 1090MHz Antenna from German Online Shop ~140€. ;D
So i collect Airlines Miles and i Calculate what cost 1M/ €. So when i Calculate what cost 1km Range/ € maybe the China Antenna wins...
Since you debate most advice that we offer, just go ahead and do whatever you think is best.
If its a simple wire/coil type vertical antenna, It could be trimmed to perform quite well at 1090mhz.
900mhz would make the antenna to long.
Though this would be an advantage as reducing its length by cutting
small amounts off the top would bring down the SWR and bring it into tune.
If you could provide a link (picture) of the antenna. I maybe able to provide some ideas.
the huge problem the china men show some wrong picture but when you tipe in ebay 900mhz yagi you would finde some.
how man mm i have to cut?
Sorry I just read your post...Its a yagi you could trim all the elements a little, And it would probably work O`K.
Aluminium is very cheap and isn`t to painful to work with to make your own Yagi.
I have made a 22 Element Yagi for around $20 Aust.
My vertical antenna up about 45 feet gets me 200nm to the coast line of Tasmania.
My 22 Element Yagi up about 25 feet gets another 25nm inland.
A 12 and 15 Element at 25 feet got me 10 to 15nm inland.
Download Yagi Calculator from
http://www.vk5dj.com/yagi.html
I would have to check with the Yagi calculator to work out how much to cut off.
It would still be a compromise as the 900mhz yagi spacings will not be perfect.
I will get back to you later on that one.
Does Australia dont use the Metrical System? ???
Yes we do use the metric system. I use both as I was bought up with the imperial measure.
Its about 3 feet 3 inches to a metre.
is there an online tool who allowed me to calculate how many mm i have to cut on the 900mhz antenna?
Yes you could use the Yagi calculator to calculate the difference from 900mhz to 1090mhz.
It would be easier to bulid a 10 to 12 element yagi at about the same price.
At a quick look you would need to cut 10 to 15mm off each side of each element.
You might find that this problematic with the main driven element as it is a looped dipole.
is was looking 1 Year ago into some Antenne Calculate Website but i dont understand nothing...
And its hard to find the spareparts for. I have no tool to build one.
there for an helix: http://jcoppens.com/ant/helix/calc.en.php
but i dont unterstand nothing.
So i need new Antennas for me.
Someone in some Forum (here?) wrote that he use an Cheap 2,4Ghz Antenna for.
So i found some on ebay for an great Value.
Does the better work than a 900Mhz Antenna?
No he was using the 2.4 Ghz antenna as an example of what he found on the internet- you have to calculate the correct values for 900Mhz.
2.4Ghz antenna will NOT work
Quoteyou have to calculate the correct values for 900Mhz
what do you mean with?
Dipole for 900mhz=1/2 wave=6.1/4 ins=3.1/8 ins.each element
Full wavelength=12.1/2 ins
A 900MHz antenna will work if it does not have too much gain but as the gain increases the closer it needs to be to the required frequency.
I have carried many tests with a beam and can say I have never had any useful success using a beam for ADSB. Here is the problem. A beam is looking for signals in a straight line and as soon as an aircraft goes above the antennas horizon it is picked up by the dipole element in the antenna. If they where of use I would sell them. Spend your money on a good quality reasonable gain vertical
Regards