UHF Radio Aerials

back to radio school for you........metal between the antenna and the intended target......balony.......the freq 477 mhz has a wavelength long enough to pass through the metal of a car body a 1.4 ghz signal is about 15cms wavelength so how long is the 477 mhz about 2 metres i think......so it would take an object that thick between the antenna and the intended target to block the signal and the extra 2db will
definatly be noticable since gain is an exponention measurement it may mean the difference on flat ground of up to 50km range....and finally gain has nothing to do with the frequency range of the antenna it is quite possible for a 4.5 db stick to have the same frequency range as a 9db stick..gain is the amount of amplification of a received/transmitted signal ....mine is on the bull bar i can talk to the car behind me.....and your gonna ask why when your under a metal awning doesnt your uhf work mine does.......think you need to check the loss of your antenna/cable/connections..... 1 dbm is good 2 dbm is bad....bet yours is 4 db plus if you cant talk to the car behind you when you had it mounted on the bar it is what kills most uhf rads that ive worked on .....and i am willing to bet even now with yours on the roof your radio works well in hilly country but the range is bleep poor in the flats regardless of the gain you have fitted ...would i be correct

I'd gor for that size myself if it wasn't for car parks. Enough hassle with the HF :)

BTW the 420-450 MHz amatuer band is the "70cm" band, so UHF CB should be slightly shorter in wave length.

ok so 2metres was a bit long but it was a guess 70 cms ....still long enough for the car not to interfere.....

Australian UHF (479/477 mhz) has a wavelenght of 62 cm (620mm).
Darryn

cheers darren .....62cms is still long enough not to have the car body muck it up......