I am very interested to buy 4 or more of these cams as below
Can anyone tell me if I can use 4 these kind cams for a property simultaneously, ie. each show own view without interferring the other cams? In other word, can I tune each cam/receive with its own frequency different from other cam/receivers?
The answer is that it depends on the size and characteristics of your property. Wireless microwave cams generally require a line-of-site path between camera and receiver. You may get a picture when setting up a camera. The big question is: Will you always get a picture, 24 hours a day, in all weather conditions, no matter who is walking around, or getting reflections from vehicles driving by?
I set a couple of this el cheepo cams outside my front door and garage and noticed that there were performance issues when the temperature dropped below 50, reception would be impaired. I was not satisfied. YMMV....
If you set up 4 cams on different channels, it is unlikely that they will interfere with each other, but that further constrains the location of your receiver(s).
One other issue with cameras such as these is that your neighbor (or someone driving around with a receiver) can pick up the signal and see what's going on in or around your house. Not good if you have indoor cams and like to walk around in your underwear.
Also, the low level light performance of very cheap cams (such as this) leaves something to be desired. They may be totally useless at night.