Just a quick one to see if anyone can help.
As yet I am still not up on antenna's and the working of etc etc....
I have a ChainLinkDare UHF system which works good. The only problem is the rubber duck style aerials on the RX. This causes a right pain when trying to mount on the aircraft.
Can anyone either suggest where to buy, how to make or even make me (obviously for a price) a pair of antenna that I can route better on the aircraft.
Is this a good start.... http://webx.dk/rc/uhf-link3/mcx-antenna.htm (http://webx.dk/rc/uhf-link3/mcx-antenna.htm)
Maybe even this?!?!
Build IBCrazy's 433MHz Turnstile antenna for FPV (http://www.youtube.com/watch?v=sCypz0ZeDdo#)
I presume all 433mhz RX antenna are the same!??!!?
Hope someone can help, sure they can.
Thanks
Simon.
You could try making a simple dipole
You want to make up a Dipole Simon, you can choose the length of the tail to suit your installation. They are very easy to make.
Quote from: Coyote on December 18, 2012, 12:28:46 AM
You want to make up a Dipole Simon, you can choose the length of the tail to suit your installation. They are very easy to make.
Cheers chaps.
It was more the length I was wondering about. With UHF does the length matter?!? Does it effect the RX's ability to get a signal?? Or is there any formula to work out how long they need to be.
Cheers.
Do you mean the aerial elements out the coax feed to the aerial?
The coax can be a long a you need really. But the elements need to be a certain size, a wavelength, or half wavelength @ 433 mhz, so around 70cm or 35cm respectfully.
Here's a good thread on making a half wave dipole http://fpvlab.com/forums/showthread.php?3156-433MHz-Half-wave-dipole-for-LRS (http://fpvlab.com/forums/showthread.php?3156-433MHz-Half-wave-dipole-for-LRS)
Most people go with half wave because of the smaller physical size of the aerial.
Does that help?
If you use RG316 for your tail length the db loss down the cable on UHF frequencies is tiny, so you can use literally meters of it.
Both the elements want to be between 16.4cm and 17.5cm long each for 1/4 wave. Various people say one length or the other, it depends on if the elements are inside tubing also.
I always make mine to 16.4cm which did fine @10km with 100mW output
That is perfect chaps!!!!
I will go and get me some SMA connectors, wire and coax.
THANKS!!!!