parabolic antenna and AP on the same pole

Hi all, I have to install a 24 dBi parabolic antenna and a LinkSys WRT54GS AP in a sealed box on the same pole, on the roof of a building.

The parabolic antenna coax cable is rather short, so I'll have to put the AP sealed box on the pole, just behind the parabolic antenna, maybe even in the same orizontal line of the illuminator.

Here is a PDF document containing a picture of the parabolica antenna:

Will there be any problem for the radio signal or anything (interference, noise, etc.) in such installation?

Do you have any suggestion for a good installation?

I preferred to buy a N to RP-TNC adapter instead of an additional pigtail to reduce the signal loss.

Thanks a lot.

Reply to
meATprivacyDOTnet
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Any help?

Thanks.

Reply to
meATprivacyDOTnet

Sorry. I forgot to answer.

There's no problem with putting the radio in a box behind the dish on the pole. That's the most common location. There are some environmental concerns which I don't wanna go into right now. Use a drain hole *OR* pressurize the box. Paint it white to avoid solar meltdown. Heat sinks conducting heat to the outside are a good idea.

However, I did get a suprise from one such installation. The Orinoco radio part of the cheap router (AP1000) was not RF shielded. The radio in the plastic PVC elecrtrical box was picking up interference from a nearby access point located behind the dish. I determined the cause of the problem with the traditional aluminium temporary foil shield. The plan was to replace the aluminium foil and electrical tape wrapped plastic box with a proper metal box. However, the owner was cheap and has left the foil in place for about 6 months so far. I haven't seen it but he also notes that some of the other wireless boxes on the rooftop are now sporting aluminium foil gift wrapping. Anyway, put some effort into shielding if you're in a RF polluted area.

I always wanted to put a small umbrella over the access point.

I don't think Goretex will do anything useful. The problem is condensation, not precipitation. The heat from the inside electronics will help with condensation, but not in a "sealed" box full of moisture loaded air. There has to be some place for the water to go (or pressurize plus dessicate and not worry about it).

Reply to
Jeff Liebermann

I thought Jeff would leap at this one. You're doing what he recommends, putting the radio outdoors with the antenna.

I dont' seem to come up with a good reference in this group, but I did see a good writeup quite a while ago.

You don't want a completely sealed box... I don't think. There should be a "weep" hole at the bottom to allow for thermal changes, both ambient and equipment caused. In a bad weather environment, you might cover it with Goretex, but a small hole facing down is probably okay.

Craig's is a long link, with good mapping detail.

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Reply to
dold

Okay, I'll drill a small hole in the bottom of the sealed box ...

Should I use any special paint or regular white paint is okay?

About the heat sinks, what types do I need? How do I install them?

I am going to use a LinkSys WRT54GS wireless router, I hope it has a good RF shield!

Thanks.

Reply to
meATprivacyDOTnet

I kinda like automotive gloss white enamel paint for metal boxes. It takes longer to dry, is harder to handle, and really dries hard. Any type of latex or urethane paint will also work. Just make sure it's suitable for outdoor use.

I've been tempted to use spray aluminium paint for both heat reflection and shielding, but have never bothered to try it.

We went through this in a previous message. *MEASURE* your heat rise on the probable hot chips and power regulator. If it's only a few degrees above ambient, don't worry about heat sinking. If it gets hot, figure out some way to get the heat out. See the article at:

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clues on heat sinking.

It will be better than an Orinoco PCMCIA card. The Orinoco card has built in antennas on the card in addition to the external antenna connector. If you have co-located 802.11 radios on the same roof, one the same channels, be prepared to do some shielding.

Reply to
Jeff Liebermann

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