Page 1 of 2

Linksys WAP Antenna

PostPosted: Fri Aug 02, 2002 6:45 am
by programmergeek
What type of better antennas cann I get for my linksys access point. I was told the connector on the back is a little odd. I basacally use this to cover my house and just need a little more reception power to get through my cordless phone.

PostPosted: Fri Aug 02, 2002 6:57 am
by Thorn
The connector is a Reverse Polarity TNC. (RP-TNC) A TNC is a standard microwave RF connector.

You can get any kind of ISM band antenna you'd like for the WAP-11. Fab-corp.com sells some, but I like SuperPass.com. If you do it, however, two things: 1) Use only one antenna, and 2) make sure you turn off "Diversity" in the firmware. Set the antenna port to whichever one you connected to the new antenna.

WAP 11 and 8dBi antennas

PostPosted: Fri Aug 02, 2002 10:44 pm
by Calcon
Thorn,
Why only one antenna? I have been playing around with this same setup. My first mistake was to use RG-58 instead of LMR 195. I figuared a 2' jummper wouldn't be a big deal. Was I wrong! Anyway I finally got LMR and made new jummpers and it worked much better but not much more than the 2.2 dBi antennas that come with it. When I did a outdoor test I got about 150' more distance out of the high gain antennas (8dBi). I used a 5dBi gain mobile antenna on my truck and made 2 runs. One with the 8dBi and one with the stock antennas. I set the access point on the cooler in the driveway and did my test. I was hoping for better results. If you add my gain in distance to a circle I got 300 more feet coverage. It would be nice if I could see a RF level graph on the AP to see if the high gain antennas hears any better. The next step is an AMP 250 or 500 mW, and a longer run of LMR 195 or 400 to the roof.

Thanks for any input!
Calcon

Originally posted by Thorn

1) Use only one antenna, and 2) make sure you turn off "Diversity" in the firmware. Set the antenna port to whichever one you connected to the new antenna.

PostPosted: Sat Aug 03, 2002 5:57 am
by Thorn
Search on "diversity" and "multipath". This has been covered a in a lot of detail elsewhere on the forums. Many times.

To summarize: Two antennae setup like this are done so to defeat multipath issues. It is a very specific RF design. Moving the antennae away from each other defeats this design, and they now longer function as they should. This is bad, and may result in all sorts of unusual behavior that the designers never intended.

This is one reason that the FCC wants the connectors to not be "generally available to the public." If you don't know what you're doing with this stuff, they want to make it a little harder to screw up the whole works. Plus, it can also be potentially dangerous.

BTW, there is no need for an amp. Generally, amps are bad news unless you know what you are doing. I have a Linksys WAP11 that goes over 2 miles, unamped, with a 4.5dBi antenna.

PostPosted: Sun Aug 04, 2002 6:00 am
by kensington
Thorn - May I ask what antenna you are using ?

PostPosted: Sun Aug 04, 2002 7:15 am
by Thorn
SuperPass SPDG120 http://www.superpass.com/SPDG12O.html w/15' of a LMR 195. No pigtail. A RP-TNC on the AP end, and a male N on the other. I make my own cables.

PostPosted: Sun Aug 04, 2002 6:26 pm
by Need BB
What are the best antennas for the linksys and should I get 2 of them?

PostPosted: Sun Aug 04, 2002 6:38 pm
by Thorn
Bad question. Best for what purpose?

As for getting two, if you are moving the antennae away from the WAP, then no. READ about four posts up. It was just answered! Did you read any on this thread before posting?

PostPosted: Mon Aug 05, 2002 12:11 pm
by Need BB
There are 2 antennas for a reason! What antenna would be best for range I need to add a about 500 feet.

PostPosted: Mon Aug 05, 2002 6:12 pm
by Thorn
Originally posted by Need BB
There are 2 antennas for a reason! What antenna would be best for range I need to add a about 500 feet.


Guest,
First of all, Thank You. I appreciate the support. Sometimes I do wonder...

Need BB,

Under most conditions, a 3 to 5dBi antenna will be fine for an additional 500'.

Spoonfeed Mode ON

Yes, there are two antennae, and yes, they are there for a reason. A very specific reason. That reason is called DIVERSITY. It is used to deal with a specific problem with microwave radio frequency communicaion. That problem is known as MULTIPATH.

Now, I quote my earlier post FROM THIS THREAD, since it seems you cannot, or will not read higher. "Two antennae setup like this are done so to defeat multipath issues. It is a very specific RF design. Moving the antennae away from each other defeats this design, and they now longer function as they should. This is bad, and may result in all sorts of unusual behavior that the designers never intended.

Note the key sentence above: Moving the antennae away from each other defeats this design, and they now longer function as they should. This is the reason you should turn off diversity in the WAP11 firmware. The antennae no longer function within the intended parameters.

This is also the reason that you only want and need one antenna. Once diversity is turned off, the antennae no longer function together, and it fact, may cause problems with each other.

Again, I echo my earlier post: "Search on "diversity" and "multipath". This has been covered a in a lot of detail elsewhere on the forums. Many times.

Spoonfeed Mode OFF

n00b ?

PostPosted: Mon Aug 05, 2002 8:54 pm
by kensington
OK, I've got a couple of Dell True Mobile AP's (rebranded Cisco AP 4800) What type of connector is that ? What if I just take one of the anntennae apart use the connector and solder on a homebrew omni ? Will that work ?

Re: n00b ?

PostPosted: Mon Aug 05, 2002 9:54 pm
by lincomatic
Originally posted by kensington
OK, I've got a couple of Dell True Mobile AP's (rebranded Cisco AP 4800) What type of connector is that ? What if I just take one of the anntennae apart use the connector and solder on a homebrew omni ? Will that work ?


what model is that? the True Mobile AP's i've seen have just been rebranded ORiNOCO RG's

PostPosted: Tue Aug 06, 2002 5:23 am
by kensington
It's a year or so old. On the back it says;

Aironet
AP 4800
Model 4822B

if i can get the $500 week old digi to work :mad: i'll take pics.

I was also thinking last night (in my simple not all that knowledgable mind) about the connectors for the mini-PCI, what if I order more connectors from Dell, could I then cut and solder to extend the cable for an external antenna ?

PostPosted: Tue Aug 06, 2002 7:55 am
by kensington
top

PostPosted: Tue Aug 06, 2002 7:57 am
by kensington
back