So I did put a camera on front of my diesel engine, then ran the wires along the inside of the hand rail, made a little half loop to the next car. The 2nd car had a battery pack and the TX. I thought being in a cool house with a ceiling fan moving air would move enough air to remove the heat. Nope. It got hot. So ive got to add a fan and maybe mount to a small alum heat sink to help it out. Or install in a boxcar to force the air across the TX and exhaust the heat out the back / top.
Didnt want to push a car, or have camera on engine in a fixed position. Like the pivot method on a truck. Until I find something better, I just hot glued the camera base to the front engine knuckle, taking time and making sure nothing got into the pivot pin mechanism.
Ill have to post some pics tomorrow, but it does work. Have the feed ran to living room tv. Tried a few different antennas... they all seem to have the same results for me.
What is the output power of your Transmitter? My first FPV camera car has a FOXEER TM25 transmitter, it is user select-able between 25 / 200 / 600 milliwatts. I always left it at 25 to reduce power consumption, lower heat output and increase the battery life. Even at 200 milliwatts it was barely warm.
Unfortunately, my experimentation with different antennas really didn't improve signal quality much on the analog system. The best results were using a good omni antenna on the transmitter and a directional antenna on the receiver that was pointed in the general direction of where the camera car would operate.