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:
<http://www.stelladoradus.com/pdfs/2.4/parabolic/grid/24%20SD24.pdf>

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.

On 12/17/04 3:54 PM, meATprivacyDOTnet wrote:

> 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:
> <http://www.stelladoradus.com/pdfs/2.4/parabolic/grid/24%20SD24.pdf>
>
> Will there be any problem for the radio signal or anything
> (interference, noise, etc.) in such installation?

Any help?

Thanks.

meATprivacyDOTnet <(E-Mail Removed)> wrote:
> On 12/17/04 3:54 PM, meATprivacyDOTnet wrote:

>> 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:
>> <http://www.stelladoradus.com/pdfs/2.4/parabolic/grid/24%20SD24.pdf>
>>
>> Will there be any problem for the radio signal or anything
>> (interference, noise, etc.) in such installation?

> Any help?

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.
http://www.craig-bartell.com/

--
---
Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8-122.5

On Mon, 20 Dec 2004 19:10:48 +0000 (UTC),
(E-Mail Removed) wrote:

>meATprivacyDOTnet <(E-Mail Removed)> wrote:
>> On 12/17/04 3:54 PM, meATprivacyDOTnet wrote:
>
>>> 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:
>>> <http://www.stelladoradus.com/pdfs/2.4/parabolic/grid/24%20SD24.pdf>
>>>
>>> Will there be any problem for the radio signal or anything
>>> (interference, noise, etc.) in such installation?
>
>> Any help?

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

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 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.

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).

>Craig's is a long link, with good mapping detail.
>http://www.craig-bartell.com/


--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558

On 12/20/04 8:48 PM, Jeff Liebermann wrote:

> 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.

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?

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

Thanks.

On Mon, 20 Dec 2004 22:16:24 +0100, meATprivacyDOTnet <(E-Mail Removed)>
wrote:

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

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.

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

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:
http://www.sveasoft.com/articles/armored/
for clues on heat sinking.

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

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.


--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558