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1GHz TV Transmitter Amplifier

Inside the camera you see the camera board and the small 1GHz transmitter module.

The image sensor chip

Closeup of the so called 50mW transmitter module, its output is only 8mW !

A thin coax was soldered to the output of the transmitter module, so I can measure the output amd feed it to a buffer stage.

TX module with coax cable

The spectrum of the transmitter module showed the 1Ghz carrier at about +9dBm and 2GHz harmonic at -6dBm

I took a closeup of the cable colours and connections, in case if a wire should fall of.

Here is the connections. WARNING ! I found out that the powercord plug actually was a +5V regulator also !!

First test of the buffer amplifier. I used external +5 V supply for the testing, this board layout was made for another amplifier project a while ago.

The hole in camera was drilled up so the coax can fit, and camera was assembled again.

The output filter and AH1 schematic was made in a hurry :-) the filter removes all the harmonic problems,
the input coil 5.6nH and 3.9pF improved output power and also remeved the harmonic

A LM340S makes 5V for the AH1 amp and the 5V for the camera module.

The board was glued to the back of the camera using heat-glue as usual.

I used a LP2951 lowdrop regulator to make 9V for the camera transmitter module,
also note the reverse protection diode !

Ready to fly ! The antenna is 6.7cm long both for the transmitter and reciever
Output is now 70mW but if this is not enough to give perfect picture, I will just add one more amplifier board
Let us see after some more test flights.


To get the power from the car, i soldered a 4 pic IC connector, the two pins in the mittle is + and the two at the edge is -

When car is turned on the power supply to the camera is also turned on.

Closeup of the camera power plug

Ready to first test..

The motor peak currents generated too much voltage noise on the supply, so I just added a schotkey diode and 2200uF capacitor to the camera supply.
I also added some ferite breads to remove some radio interferance from the camera into the RC car.

The first 5 minutes it was dificult to controll the car around my flat, but after a while of training only looking at a TV set, it was possible to drive really fast and accurate around.
so I guess the same training must be done with a plane before perfection in controll can be achived.

car-test1.avi 575 kb My son is on the controll ! while I'm filming the TV set with a digital camera :-)