They scavenge it from another part of their coverage! So, you increase the effective power in one direction and significantly reduce it in another.!

Quite correct MHC but it appears that you are just thinking about the horizontal radiation pattern from antennas such as Yagis

Think about the vertical radiation pattern from an antenna such as a vertically mounted dipole for instance.

There is a lot of wasted energy being transmitted above and below the remote station (the device I want to connect to my router's Wifi).
If I can bring that pattern in and concentrate it's pattern more laterally (but still omnidirectional) then Bob's your Uncle.

In reply to a post by VWGolfman:

They scavenge it from another part of their coverage! So, you increase the effective power in one direction and significantly reduce it in another.!

Quite correct MHC but it appears that you are just thinking about the horizontal radiation pattern from antennas such as Yagis

No, I'm thinking of all antenna designs, from full 3D omnis (spherical) through to basic directional ones with radiation in a single 2D plane.

OK anyway we are on the same wavelength

Where does the "relative gain" come from with those longer omnidirectional antennas?

I presume they concentrate the "wasted" radiation around the horizontal plane just like a spare tyre around my belly?

Antenna efficiency and as you say concentrating the power into a "torus" rather than a ball. Imagine taking a large ball and compressing it a little, then a little more and more and more ...

Thanks for the info

Please can anybody explain the differences between these three below and which I need (I have bog standard ADSL broadband over my telephone line)......

* Billion BiPAC 7800N Dual WAN ADSL2+/Broadband Wireless-N Gigabit Firewall Modem Router

* Billion BiPAC 7800N 10BASE-T 100Base-TX 1000Base-X 100/1000 Mbit/s 2.4 2.484 GHz 300 Mbit/s 1 Mbit/s 24 Mbit/s (BiPAC 7800N)

* 191394: Billion BiPAC 7800N - Dual WAN ADSL2+/Broadband Wireless 't;N't; Gigabit Firewall Modem/Router (Broadcom chipset) (BiPAC 7800N)

best option would be to purchase high end wifi access point from ubiquiti:
http://www.wifi-stock.co.uk/products/ubnt.html

something like a bulletm2hp would be ideal

In reply to a post by VWGolfman:

Thanks for the info

Please can anybody explain the differences between these three below and which I need (I have bog standard ADSL broadband over my telephone line)......

* Billion BiPAC 7800N Dual WAN ADSL2+/Broadband Wireless-N Gigabit Firewall Modem Router

* Billion BiPAC 7800N 10BASE-T 100Base-TX 1000Base-X 100/1000 Mbit/s 2.4 2.484 GHz 300 Mbit/s 1 Mbit/s 24 Mbit/s (BiPAC 7800N)

* 191394: Billion BiPAC 7800N - Dual WAN ADSL2+/Broadband Wireless 't;N't; Gigabit Firewall Modem/Router (Broadcom chipset) (BiPAC 7800N)

They're all the same

In reply to a post by VWGolfman:

Hi my ZyXEL P661-HW router / stock antenna doesn't quite have enough effective power / sensitive ears to cover my whole house.

Is there a recognised router which is more powerful and/or has a superior antenna system?
I would like to try to keep below £150 if possible.

I have ADSL broadband over the telephone cable.

Many thanks for any advice.

Hi, the most powerful wireless router - BT Business Hub 2Wire 2700HGV version (1) only flashed with v4.25.19 SBC firmware.
It will give 400mW wireless power and 1 to 10 wireless power level settings, normal wireless power level is setting 4.

http://bt2700hgv.tripod.com/021.htm

The v5 2700 can also be tweaked to give 400mW