I can see the intent behind using the existing rear demistor as an antenna ( larger area to pick up incoming signal ) but do not have enough direct knowledge to speak about them authoritatively. Besides, the car is constantly changing direction so you'll never have the antenna facing the transmitter towers all the time.
In regard to boosters should you need them, you'd adjust it down from the strongest signal you can find. Besides, over amplifying a signal is really obvious onscreen.
In regard to digital signals, all of Australia currently has the digital signal being broadcast alongside the analog signal and this will continue untill 2008 ( from memory anyway ) at which point they will stop broadcasting the analog signal. You've got time to enjoy your current analog tuners. If however you are keen on going digital TV tuner now, then you'll have to find a ready made digital one. If they're not currently available then don't worry about it for a few years.

Oh by the way, 300 ohm was the old style flat ribbon cable system that we had in our homes a couple of decades ago and beyond and if you had to plug that into a modern TV and video setup, you had to fit a balun to convert to 75 ohm.
75 ohm is the current standard and is the round co-axial cable we plug into the back of our TV's and videos. I'm sure you'll find that only the 75 ohm tuners are being made.

Last edited by Vic on Thu Jun 23, 2005 2:30 pm, edited 1 time in total.

there are some good cheap digital boxes on the market that can be moded for cars

All major cities use horizontal recieving antennas only some smaller cities use vertical antennas, in any case the demister will recieve more gain on horizontal and half gain vertical, and if your falcon is a sedan the rear screen will have a curve in it making it not so directional, as for amps most guys use a masthead amp as they can pickup lower DB signals better and they are adjustable

Yep, capital cities all have TV transmissions broadcast via horizontal propagation with exceptions being some country regions ( which you can spot because their home antennas are mounted vertically ).

Anyhow, check to see what the luxury cars are using as antennas if you want the best.