the ultimate video system

[mr.dani]

Hi all,
I've been working on an RC vehicle that will be used for wildlife filming . I tried so many FPV systems (up to 2.5 watt) with cp antenna for  the video tx and I used very high gain patch antenna for the video rx . from my experience I can tell you that mostly fpv systems don't work well on the ground specially behind obstacles (where there is no line of sight)  and in the jungle environment . this fact caused me to start searching for the ultimate video system that wont let me down . I found out that transporting the video signal by a long thin wire will be the best solution for  this huge problem . I intend to use 4000 m of copper wire with 0.4 mm diameter , but another problem came out to the surface which is the lost of signal through this long thin (high resistance about 20 kΩ ) wire , so I needed to magnify the video signal (coming out of the camera) by using a simple magnifying circuit before sending the signal through the wire . in fact I'm not expert in electronics , but I still know the basics , because I've made a couple voltage regulator myself beside the knowledge achieved from my neighbor (he is a high school teacher) . so what I hope of you guys is to help me in this magnifying circuit because I'm lost . and if you don't know how to make this circuit just send me the links of electronics forum that you think they have the answer of this question and let me enjoy doing it my self . I can't design a circuit from zero point but I'm skilled enough to convert it from a sheet of paper to a real thing .
By the way I solved all of the mechanical  problems related to the wire using
 

[Tecnic]

Repeaters would most likely be your best bet, simple and cheap too

Set up a 1.2 receiver high up (tree/poll ? ) fitted with a CP omni antenna (skew), have the video output go into a 1500mw 5.8ghz transmitter with a directional antenna (7 turn helical etc) pointed straight at yourself
Have a 1.2GHz 800mw transmitter on the ground craft with a CP antenna (clover)

Use UHF control for the vehicle

[Martink1974]

If you intend to only go 4000m technic is defo right just get your rx antenna very high would be my first choice. Might have to use a balloon to get antenna high but would be much more reliable than using a thin copper wire

How big is the ground based vehicle , if large would be pretty easy for it to track it's start location ?

Also what frequency video tx have you tried at 2.5watt and what make

[bigMouse]

Can't tell you much detail because I have never looked into it, but a possibility might be to use an IP camera and send video via 3G network! Of course, you will need 3G connectivity. Ground based video is not as demanding as real time flying video, and any small delay would be acceptable I guess.

[mr.dani]

If you intend to only go 4000m technic is defo right just get your rx antenna very high would be my first choice. Might have to use a balloon to get antenna high but would be much more reliable than using a thin copper wire

How big is the ground based vehicle , if large would be pretty easy for it to track it's start location ?

Also what frequency video tx have you tried at 2.5watt and what make

I am using 900 mhz (2.5 watt) fpv system

[Martink1974]

Where in world are you from 900mhz don't work too well here in uk as for cell towers but I really would have thought with right antennas you would have little trouble at 4000m with enuf elevation of receiving antennas , between metal building and suck maybe problems but grass and trees should be pretty ok , I'm presuming it not too dense as you were considering using a wire, had a look at transmitting video signal down wires and you gunna struggle transmitting a composite signal down long thin u shielded wire, would have to change the signal you were transmiing down the wire

[mr.dani]

Repeaters would most likely be your best bet, simple and cheap too

Set up a 1.2 receiver high up (tree/poll ? ) fitted with a CP omni antenna (skew), have the video output go into a 1500mw 5.8ghz transmitter with a directional antenna (7 turn helical etc) pointed straight at yourself
Have a 1.2GHz 800mw transmitter on the ground craft with a CP antenna (clover)

Use UHF control for the vehicle

would you please send me the link of the best (high quality) repeater for my 900 mhz (2.5 watt) fpv system

[Tecnic]

Repeaters would most likely be your best bet, simple and cheap too

Set up a 1.2 receiver high up (tree/poll ? ) fitted with a CP omni antenna (skew), have the video output go into a 1500mw 5.8ghz transmitter with a directional antenna (7 turn helical etc) pointed straight at yourself
Have a 1.2GHz 800mw transmitter on the ground craft with a CP antenna (clover)

Use UHF control for the vehicle

would you please send me the link of the best (high quality) repeater for my 900 mhz (2.5 watt) fpv system

The repeater set up would simply be a 900MHz receiver outputing it's analogue signal to another transmitter, maybe a 1.2GHz

So you would have your 2.5w 900MHz tx on the vehicle
A 900MHz receiver mounted high on a tree/poll
An 800mw 1.2GHz transmitter getting it's input from the 900MHz receiver with a directional antenna pointing back to your base or an omni directional if you need to move the base location
At your base you have a 1.2GHz receiver linked into your moonitor/dvr, also fitted with a directional antenna pointed towards the transmitter

I don't have 1.2GHz durectional antenna (I do have omni's though), but you can check out the TX/RX stuff here:
http://www.tecnic.co.uk/FPV-Video-TX-and-RX/

Terry

[mr.dani]

Where in world are you from 900mhz don't work too well here in uk as for cell towers but I really would have thought with right antennas you would have little trouble at 4000m with enuf elevation of receiving antennas , between metal building and suck maybe problems but grass and trees should be pretty ok , I'm presuming it not too dense as you were considering using a wire, had a look at transmitting video signal down wires and you gunna struggle transmitting a composite signal down long thin u shielded wire, would have to change the signal you were transmiing down the wire

I'm living in the other side of the planet 

[BIRDS-EYE-VIEW.NL]

flying long range with low altitude in the bush can be demanding. I build lots of stuff for discovery, bbc, national geographic and others.
Especially in a rainforest with lots of moisture it can be hard to transmit/ receive any signal. On the other hand 4000 meters isn't that far. And if you can poke your antenna trough the canopy then you can do this with even very basic equipment.

But lets say you want to fly very low under canopy level then there are 2 ways which can be used.

Method one is already described here. (low frequencies for both video and controls)
other method which works better in some cases is using high point repeaters for the signals. In the past we already used them on kites, balloons and even on other drones.
With this technique we where able to fly in canyons, behind mountains etc.

Hope this helps

Wicher