Aerial Types

[eskimo]

Hi guys thanks for all the recent help. I managed to get my aunties tv working great with a new aerial and masthead amplifier.

However I basically just gave the guys at the wholesalers my figures and they gave me an aerial they though suitable.

How do I know on future jobs what type of aerial to use? I recently saw an engineer go up onto a roof with a portable type aerial connected to his Horizon meter, spent a few minutes pointing it around and then this enabled him to select the correct aerial from his van.

I have looked at a few different types and see they have 'forward gain' and 'front to back ratio' I assumed the higher the numbers the better at pulling in a weak signal but have now seen one with '12db forward gain' and '23db front to back ratio' and then a second more expensive aerial which is classed as better for weak signal areas with '17dB forward gain' but only '20dB front to back ratio' does anyone know how these figures work??

Also is it possible to get a professional testing aerial?

Thanks

 

[satelliteman]

Mainly wideband aerials but will depend on region post DSO. Some areas are going back to their original group.

 

[Robbo]

I have looked at a few different types and see they have 'forward gain' and 'front to back ratio' I assumed the higher the numbers the better at pulling in a weak signal but have now seen one with '12db forward gain' and '23db front to back ratio' and then a second more expensive aerial which is classed as better for weak signal areas with '17dB forward gain' but only '20dB front to back ratio' does anyone know how these figures work??
Thanks

The front to back figure is obviously the ratio of signal that would be received at the front of the aerial compared to behind it, and the gain is how much it would receive relative to a dipole.


Have a read of this guys site:-

_http://www.aerialsandtv.com/aerials.html#AerialTheory(Yagi)