Antenna Cable solution

[Kiimas Karu]

I would like to mount my 19 db wifi antenna onto the roof of my apartment building. The amount of cable I would need would be approximately 15-20 meters down to my flat and connected to my AP/laptop.

What kind of cable should I use? LMR 400? What can I expect of signal loss?

I do not have the option of installing the nic near the antenna and there is no possibility of any power supply on the roof. I read here about the Rootenna, but this would not be possible.

What other solutions do I have? Is it possible to connect the antenna directly with an ethernet cable without a router nearby?

Does there exist a connection converter from a N-connector to an ethernet or USB?

The equipment I have is a laptop with a Orinoco gold card and the OvisLink WL-5460 AP.

Thank you in advance for your advice

[fastpakr]

Why do you say that putting the NIC nearby or using a Rootenna would not be possible? You can run POE up to 100 meters.

[Kiimas Karu]

The only space on the roof that I can connect the antenna is to an existing pole that has satellite and tv antennas already attached. I imagine that I could use the rootenna, but I prefer to use the antenna I already have and I do not know if the rootenna is available in the country I live.

[M/Q]

You can still use the antenna you have, just mount the Radio up there as well in a weatherproof container and as fastpakr mentioned run PoE up to it. That approach is a great deal more sound and less expensive than running LMR400 and all of the connections.

[Kiimas Karu]

The PoE is interesting, but I would still need to buy an extractor and injector to have it work with my AP and the cable too. Also, it is a high pitched tiled roof with no place for a weather proof box.

Running the LMR400 will be the same as the CAT5 (in this country everyone justs throws the cables down the sides of the buildings!) and it costs here about $1.75/meter. If i use cable how much signal loss am i expect with LMR400 for 20 meters

[fastpakr]

4.3dB plus connectors, I believe.

[mark78]

Trying to figure this out too...

The calc I found said that for a 20 foot run (8 meters?) I would lose about 6.7db to cable attenuation. That kinda ****s. You can add more power somehow but not sure how that works. I'm trying to figure this one out too.

[mark78]

I found a calculator though I'm not sure I used it right.

It says if I am at 80dbw and a 1dbi antenna with 0 feet of cable I am sitting at about 18db output (budget).

The 400 cable I I believe I lose 31db over 100 feet. If my run is 40 feet with this cable, my output drops to about 10, if I use a 7dbi antenna, and bump the power of the radio up to 200, I get back to 19db output budget.

If someone knows, do these numbers roughly sound OK or way off? What about the signal from the antenna back to the AP??