You should investigate placing a decent gain passive radiator on the high spot and a good gain antenna at the home , some simple testing with the laptop will confirm this suggestion but do remember the passive needs specific high gain and careful installation , good luck
I think we have those in Middletown, CA, on the 707-987 CO.
I was thinking of big, flat, oddly positioned buildings on the side of hills in the middle of nowhere. I assumed that these were telco flat reflectors, but I can't remember why, now ;-)
Ok, here's a possible option for you. Run RG-6/u coax up the hill and install a dish antenna pointed at wherever. 4 miles is a long shot, but it might work. Satellite grade RG-6/u coax is about 11dB/100ft. Therefore, your attenuation will be 66dB. Let's grind the numbers again.
So, let's see what happens if you run better coax up the hill. LMR-400 is 6.7dB/100ft loss or 40dB loss. That yields -113dBm rx signal level which also won't work.
I really shouldn't post ideas that won't work, but I thought the exercise might be of interest. Basically, the radio needs to be on top of the hill.
Much more interesting is what equipment needs to be installed on the hill in order to connect to an access point that's 4 miles away. If you install the big +24dBi dish with an attached radio, the link budget looks like:
Starting at the access point end: TX power = +15dBm TX coax loss = 4dB (3ft LMR-240 plus some connectors) TX ant gain = 8dB (omni) Distance = 4 miles RX ant gain = +24dBi (dish antenna) RX coax loss = 4dB (3ft LMR-240 plus some connectors) RX signal = -85dBm (at 5.5Mbits/sec)
That yields a fade margin of 7.8dB which isn't going to work. You need 20dB of fade margin for a reliable connection. That's about a
12dB shortfall, which is not going to be made up with a bigger antenna or less cable loss. Your only hope of this thing working is if the service provider has a better antenna system than my insipid 8dBi omni guess. It might be a higher gain sector antenna which has a better chance.You stated that you could barely make a connection with a biquad. Well a typical biquad is about 9dBi gain less coax loss. If you replace it with a 24dBi dish antenna, you'll pickup 15dB of gain, which should make the link useable. It really depends on the antenna configuration of the central access point. Can you supply any details of their antenna and radio system.
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It might be a problem because the distance to the access point is 4 miles (6.44km) distant and we have no clue as to what type of antenna system is at the access point end. I ran the numbers in: |
My guess(tm) is that unless the access point has a directional (sector) antenna system or much higher gain omni, a 4 mile link may be functional, but not very reliable. However, the fact that it almost works with a biquad antenna leads me to suspect that a bigger antenna may do the trick.
Dont get your t*ts in a tangle Jeffy , I was reading passive repeater which should do the job , I have built something very similar with success and it is certainly worth looking at , do the figures if you want .
Rethinking it I'm wondering is running some 2.4 mm cable twin up there and feeding 24ac to a ap at the top is feasible , I guess we wont really know unless some one does a walk over and posts some measurements of rx sigs at the hill top .
Exactly my point , of course you made some guesses but if the gent takes a walk and makes some measurements with what he has ...
Photos. Found by punching "solar" into the searth thingus.
I was just reading this thread, it's pretty interesting! I'm curious how you end up solving your problem.
Anyway, a group call SoCalFreenet, down in San Diego, is *really* creative when it comes to building a network of relay points for their backhaul network. Poke around their site a bit and see what they're building. One project to peek at is the Low-budget Outdoor Solar Wireless
good luck!!
-Jonathan
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