How does it work?

[Addy]

Hello Alex, you are the person to talk to i hope. Can you explain in simple words (Jip and Janneke taal we say here in holland, childbooks) how does a transmitter signal actually gets to the receiver. I've know the transmitter sends out a signal, that is clear but what is see is that the receiver also sends out a signal (from the video antenna polarisation). Now usually when you send to "things" into each other you end up with a bang i mean when to cars for example drive in a straight line into each other you have a problem in the middle you don't end up with to cars at one end. So i hope you know what i mean and can explain it in simple words how the transmitter signal actually gets to the receiver after it has found the receiver "beam"

Thanks

Addy

[IBCrazy]

Well, not quite. The best way I can describe it is this:

The transmitter sends out a signal. The direction is determined by its antenna. This signal travels out and deteriorates in strength as is goes. Think of it like a light bulb or perhaps a lighthouse radiating out light.

Now the RX antenna is "looking" for that signal. Again the area it looks is determined by the RX antenna. Directional antennas can "see" farther than omnis. Think of it like this: You can look at the moon and see a round light. Use binoculars and you see some detail. If I give you a telescope, you can see detail very well. I am adding directinality to my system thus adding gain. Same thing goes for an RX antenna.

-Alex

[Addy]

Oké i think i get the picture. I laways thought that the actual signal from the tx had to get to the rx like electrical power which has to get to the light bulb to make it glow, but the rx can sort of see in the distance the signal from the tx depending on what kind of antenna u are using he can "look" further away. thanks for the answer
I have build a 6 turns helical from your rcgroups tutorial and i am quit happy with it but in fpv nothing is perfect so i want to try and perfect it, from the calculations you gave the diameter of the coil should be 15,85mm at 5,8 (hope i am right) now i have found this grey electrical pipe which is 16 mm but has quit a thick wall so with some sandpaper it should easely be made to 15,8. is 15,8 correct for pvc because on rcgroups you wrote that pvc shifts the frequentie down 5% but i am not quit sure how to translate that to diameter.

Thanks for the help so far.

[IBCrazy]

Why not use a wooden dowel rod? That's what I use

-Alex

[Addy]

Why not use a wooden dowel rod? That's what I use

-Alex

Hmm, Why do i always try to do things the difficult way. oké so it doesn't matter if it is a solid rod as long as it is wood? a friend of me has a (draaibank, picture below) don't know how you call it in english and he can make it to any diameter up to .01mm as long as the wood is hard enough.

[aeryck]

The english for that tool is called a Lathe. =] And yes, that'll let you spin a hunk of wood to precise diameter.