On Apr 18, 7:52*pm, Jeff Liebermann <je...@cruzio.com> wrote:
> On Fri, 18 Apr 2008 02:58:13 -0700 (PDT), Adam Chapman
>
> <adam.chap...@student.manchester.ac.uk> wrote:
> >I'm looking at splitters to use on my small aircraft which has two
> >antennas broadcasting video data.
>
> At what frequency? *You can get power dividers that are fairly narrow
> band and are optimized for a range of frequencies, or you can get
> broadband devices that cover a large range of frequencies. *Also, what
> power level are you transmitting? *Power dividers have some loss and
> will smoke if over driven. *Also, does it have to be TSO approved? *
>
> Is your "small aircraft" aluminum body or fiberglass? *If fiberglass,
> you install the antennas inside. *However, that means that the two
> antennas will "see" each other, which means your antenna pattern will
> probably be full of nulls and peaks. *Power splitting between dual
> antennas really only works if the antennas are on opposite sides of a
> a shielded (aluminum) body, and cannot "see" each other.
>
> >I'm new to RF stuff, could somebody please tell me what 'power pass'
> >means and what it causes to happen?
>
> Power pass means that it will pass DC power. *That's usually in
> reference to running satellite dish LMB front ends, or tower mounted
> antenna amplifiers for over the air TV. *It's also necessary for tower
> mounted bi-directional amplifiers, sometimes used for Wi-Fi. *Unless
> you have some electronics mounted in the antenna, I don't think this
> is a requirement for your unspecified hardware.
>
> >I'm looking at splitters similar to the first two at
> >http://www.rgsplit.com/servlet/the-S...ass/Categories,
> >but if anybody knows of a lightweight option that would be great.
>
> I'm goint to *ASSUME* that you're only interested in 2.4GHz. *See:
> <http://www.hyperlinktech.com/web/signal_splitters_2400_2way.php>
>
> You can also make your own:
> <http://www.qsl.net/yu1aw/2G4spliter2.gif>
> <http://www.qsl.net/yu1aw/2G4spliterN.gif>
> It's fairly simple. *Again, this is for 2.4GHz only, not a wide range
> of frequencies.
>
> --
> Jeff Liebermann * * je...@cruzio.com
> 150 Felker St #D * *http://www.LearnByDestroying.com
> Santa Cruz CA 95060http://802.11junk.com
> Skype: JeffLiebermann * * AE6KS * *831-336-2558

Thanks for your responses.

I am going to put 2 cisco 6dB patch antennas (http://www.cisco.com/en/
US/docs/wireless/antenna/installation/guide/ant2460.html) back to
back, and would like to stop them 'seeing' each other by using some RF
absorbing material at http://www.kemtron.co.uk/arc.html, which I
havent looked at in depth yet but expect to be lighter then
aluminium.

The aircraft will be made of fibreglass so the shielding is needed.
I'm using a wifi network so the frequency is 2.4 gigs.

I dontthink the power-pass is a requirenment, although power-pass
splitters seem to be lighter and cheaper. Would using a power pass
enabled splitter actually cause any problems?

I also need an amplifier in my system and this one (http://www.rf-
links.com/AMP8_24.pdf) looks nice and small, although I dont know if
it amplifies both ways, i.e. ampllifies a trnamitted signal AND a
recieved signal. Can any of you guys tell by looking at it?

Your help is much appreciated
Adam