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wireless security camera @ the end of a 2mi long driveway. Signal only carries 300'.Amplifier/repeater? Answered

Trying to install security camera at the end of a 2 mile long driveway.The signal (900mhz) only carries 300'.Is there a (cheap) way of repeating or amplifying the signal?The camera is a

Defender PHOENIX1 Wireless Video Security System, Indoor/Outdoor Night Vision Camera




Best Answer 7 years ago

There are lots of ways to increase the range of a low power transmitter, ive played quite successfully with dishes they give very good results as well, i read somewhere of a standard low power set up achieving in excess of 47Kms using small dishes in a line of sight application.

There are other simple aerials that can be made, simply and cheaply, Take a look on some of the ham radio sites for making aerials. A lot of the materials required, can be re-cycled from a UHF TV aerial, using the same boom. The secret is to keep the coax feed from the transmitter to the aerial as short as possible, coax EATS RF, if you can mount the transmitter on the back of whatever aerial you are using, thats the ideal approach.

If you fancy a play with aerials, try this site for more info......


In short, your standard 300' transmitter, can be used with the right aerial set up to broadcast a signal 2 miles or more. I recently had the experience of working with a CCTV engineer working for the local council, he was working on the towns 1200Mhz CCTV system, the transmitters used were no different to the average video sender with a 10Mw output, the TX end had a simple dipole with mesh reflector and the receiver end, a dipole in a dish or a Yagi aerial, yet we were able to receive remote CCTV 5 or 6 miles away.

Amplifiers are another route, but tend to be expensive, i dont know if you have power down at the remote location, or if you are using solar, adding an amp would need a larger PV array as well.

There is nothing mystical about making aerials, just follow the simple mechanical instructions..Good luck and have fun.

There are lots of expensive ways... :) however... one thing you might like to try is to make a simple 90° corner reflector for your camera. At 900MHz you would want to make it with sides at least a foot long (as the wavelength λ = 33 cm)... the height should be around the same... try placing the camera's antenna around 10cm (4inches) out from the corner... you could make it out of wood and cover with aluminium foil or if wind is a problem make it from wavelength lengths of metal rod spaced at 0.05 wavelength = 1.65cm. If you have success with the reflector it might be best to make it larger 3 to 5 time the wavelength (sides more than a metre in length) ... hope that gives you something to play with anyway... I have used corner reflectors at 2.4GHz and it works really well.

Great answer. What kind of gain would this give you ? I image the higher the frequency, the better, but any numbers ?


Thanks Steve...

I would say a typical gain of around 8db for a small reflector (1 to 2 λ = 30 to 60 cm)... with maybe twice that if larger (5λ = 1.6M)... but would try using a mesh at that size... also it wouldn't be the prettiest driveway entrance :) ... though for cost(&simplicity)/db the corner reflectors are pretty good... I have seen them work up to 10km with low watt transmitters.

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7 years ago

I worked for a year and a half for a small company that was providing internet to rural houses that could not get DSL by using long range radios. They use the same frequencies and protocols that standard wireless uses but they have a much greater range. Our network reached over 75 miles from end to end. The individual radios have a line of sight range of up to 25 miles depending on what antenna is used. These are not expensive and have very low power demands. One relay station we set up was solar and wind powered. You can find used radios on E bay for very reasonable prices. Some have internal antennas and are very easy to set up. The manufacturer that had the best radios of the ones we tried is called Tranzeo. I just did a quick search on e bay and there are a lot of them listed, many for under $50.00 You need to cross reference the model with Tranzeo's web site to see if it has an internal antenna. The are waterproof and mount on a post, a roof mount or an antenna mast. Once set up you would be able to get wireless internet from your house down at the end of your driveway. So you could do more than just have a camera there. One important thing though is that the 2 you get should be the same model. Different models will talk to each other but we found it worked best when they were both the same and had the same firmware. Tranzeo has a utility that can upgrade the firmware of their radios to the current version. Don't worry if the used ones don't come with instructions, you can get the complete manuals from Tranzeo also. They are also pretty hardy. We had one survive a lightening strike. Everything else in the cabinet was toast, power inverters and switches but the radios worked just fine still.


7 years ago

new-ish to radio,but could you solder on a wire tothe existing antenne up to 300' from the receiver? justa though.
73's: KJ4ZVQ


7 years ago

i've heard of phone line, plain stuff, that's worked fine over 10000', maybe see how long you can run a wire beside the driveway before you need a repeat. as a repeater, you may be able to use simple differential op-amp and some solar cells from calculators with a tiny battery charger. certainly you wouldn't want to send rf video down it, but possibly use a digital encoder, the kind that only send changed data, wouldn't even need it that fast if you didn't need real-time, like, half second delay.

I am not an engineer, but these looked interesting:



7 years ago

Something that hasn't been mentioned as yet is signal absorption.
If you have a "visually clear line of sight" then this does not apply but at those frequencies any trees, brush or buildings are quite apt to "absorb" and hence attenuate the signal to an unusable level. Further any hills can create a shadowed area where reception will be weak at best.
Think of cell phone coverage here.. there's areas where it fades more than others. Same things will apply to your application.
As someone else mentioned.. streaming via the net would probably be well worth looking into.
Good Luck..FN

Instead of trying to make something designed to carry 300' go over 10,000'; have you considered streaming it instead? From my experience, it's probably A.) more reliable and B.) less time and/or cost to just either run a video cable (which would also need amplifiers in this case) or to stream it over the net (what I would recommend in this instance). Of course this would require a good internet connection at both ends- you may need to set up a wifi hotspot in order to do so.

.  Keep in mind that dishes and corner reflectors (and most other high gain antennae) are directional. They can be difficult to align and must have rigid mounts to maintain alignment in windy conditions. None of that is reason not to do it, just be prepared to spend some time and effort to do it right.
.  The ARRL is a great source for antenna and other radio-related info.

Have you got line of sight to the receiver ?

Add a high gain antenna at both ends. A small satellite dish would be ideal - one of those 2 foot diameter things.