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Battery powered Wireless with high gain directional antennas.
Do you have any power sources near where you want to mount the camera?
This is a page from just one cam brand but it looks like ifyou can provide power near the camera, you can run longer lengths of video cable back to the house. If there is a light out by the gate, you could probably get the power supply for the camera wired in there.
This might work; seems to run off the cell-phone network.
Trail cameras, wal mart $28.88 each
Uses 8 AA batteries and a SD Card 16GB is more then plenty
I use these as a “silent witness” around my property to see if I have 2 legged explorers on my property also good for seeing 4 legged animals as well.
If you need instant notification Dakota Alert wireless alarm works great, for vehicle detection get the metal detection version, bury the probe in your driveway and put the receiver in your house, anytime a car goes into your driveway, you are alerted. These cost about $200 or less online
Neither require internet, wi fi, tons of wiring or IT technical support. And are easy to set up cheap to buy and work.
I know these are not exactly what you are looking for but could be an alternative to something more complex and more expensive.
If you are referring to an IP camera, then you will have problems at that range. Given power at the camera location, you can go to an RF link in the 900 MHz band.
Do you have power avail at the gate location?
Is any low voltage cable already in place between your home and the gate (twisted pair cable, coaxial cable)?
I just read an article about the M240.
Tie a string to the trigger.
Get an electrician to run electrical wiring underground to near the gate? Not a cheap solution though.
Same issue on our farm. No power at the gate/camera end. Sending video over large distance is power-limiting. Ping to monitor for reference.
you can do a wired system, you need a amp for your system, some systems can’t do it.
We wired up systems with miles of cable, these were commercial systems though. You might not be able to afford a new commercial one as the camera alone can set you back 800 but you can pick up a used one. The commercial cameras have features like night vision and automatic adjustment for headlights. You can read a license plate even if they have their headlights on your camera.
there are residential systems with the range with an amp, but the cameras aren’t very good.
I use 2 raccoons with walkie-talkies. Works great as long as there is dog food in their tray.
Power over Ethernet (POE). That far you made need to step it up with a powered coupler.
Perhaps a camera with along optical zoom nearer the house.
IIRC POE, power over ethernet is good for ~100 meters.
Add an IR illuminator near the gate.
If you need to record, get an NVR (not DVR). It uses cameras which run off of CAT5 wire with network connectors. You’ll still have to run the wire, but you should be OK with power requirements for the cameras.
you need to purchase bnc wire that includes power in the wire bundle its not cheap but it allows you to hardwire a camera and comms to your gate. RG 6 or RG 59