900MHz vs. 1090MHz Antenna

[IanH]

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

[Radio2.0]

you have to calculate the correct values for 900Mhz

what do you mean with?

[shakysen]

Dipole for 900mhz=1/2 wave=6.1/4 ins=3.1/8 ins.each element
Full wavelength=12.1/2 ins

[Chris-G0WTZ]

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