WA Radio Scanner Users' Group

G'day All,

Saw VF105 in Freo and ZM102 on Flinders St this arvo and noticed both these vehicles now have 2 extra aerials mounted on the back windscreen.

They are just like mobile phone aerials with the whirly bit in the middle and mounted in the same positions as the CD cars.

Both these vehicles are fairly new VZ secure sedans with a pod fitted.

The vehicles also had the 'rubber-ducky' fitted also mounted at the rear of the light-bar.

Does anyone know the purpose of these extra aerials??

cheers

Tom

Maybe for the new digital system?

I think from memory looking at the RFI website, if you are describing the on-glass aerials which look just like a mobile antenna and not the UHF glass-mount, then its probably a data/MDT antenna... which is more than likely part of the new digital system being implemented.

NSW vehicles used to have these whirly antennas either edge on some of their vehicles plus the UHF in the middle - thus resulting in 3 on-glass antennas mounted on the back windscreen... a dead give away on unmarked cars. Nowadays, NSW have gone to boot/gutter mount antennas. Makes me wonder perhaps the glass mount option was not very effective...

Glass mounted antennae are not as efficient as gutter/boot mounted antennae. The signal is required to pass through the glass and the mountings on the glass are inherantly lossy to transmissions in that frequency range.

I have a mobile phone antenna mounted on my windscreen but only because I didn't have a place to mount the antenna on my new car at the time.

The coil in the middle of the antenna generally is to shorten the physical length of the antenna - adding a coil can effectively do the job - but a full size antenna is generally a better performer.