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### Topic: Old UK TV satellite dish to Boost RF signal (Read 2779 times)previous topic - next topic

#### trendski

##### Oct 04, 2012, 03:10 pm
Hi,

I've got an old concave UK BskyB dish and I would like to use it to "boost" a signal from my RF module attached to arduino. The RF module is a Jeenode type RF12, but my setup is not Jeenode it's attached to an Arduino Uno.

After a bit of research, I think I have to position the receiver module an exact multiple of wavelengths from the center of the dish to get it to work as a collector of "waves" and reflect them towards the RF module efficiently (ie so they mostly add up instead of cancel out).

Using the equation
Code: [Select]
wavelength = C / f

(C is velocity of light and f is freq of radiation) I get

Code: [Select]
3*10^8 / 868 MHz = 34.56 cm

I would appreciate an experienced look at my logic and Maths and some comment on it.

Am I on the right track?

Cheers
Craig Turner, blog: http://gampageek.blogspot.co.uk/ It helps with my learning if I write things down, esp. for others to follow (constructive comments welcomed to improve)

#### MarkT

#1
##### Oct 04, 2012, 05:44 pm
The reflector should be 1/4 or 3/4 or 5/4 or 7/4 wavelengths from the back reflector, and as close to the dish's focus as that allows.  ideally you'd use a dipole antenna at the end of a feed coax, but you can try just placing the whole module there.  Make sure the antenna wire is perpendicular to the axis of the dish.

Then experiment a bit !
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

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