Antenna connector Linksys WRT

Since my D-link DI-614+ died, I've replaced it with a Linksys WRT54GL router. I had an external D-link AN24 antenna on my old router. The antenna has a cable with an N connector and a (reversed?) SMC connector and the latter one connected with the router.

Now my new Linksys WRT54GL has a reversed TNC connector. Can I use my old external antenna after replacing the SMC connector with a TNC connector or are the antenna's with different types of connectors inherently different?

Reply to
Sjeng
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You should have no problem using that antenna on your new router as long as you can get the correct adapters. I can't remember off top if the 614 has two antennas or not but i know the linksys does. You'll be better off if you have two of the same antennas.

Adair

Reply to
Adair Witner

I have an extension cable for the antenna with N-connectors, so finding the appropriate N-female to rp-TNC connector is not a problem. I've seen it in a webshop for 6 euros.

I had an ancient 614 with two antennas (newer models only have one). I even have the idea that they had different functions. The old set-up was actually a mess and the performance of the 614 a disaster. The WRT performs far superior without an external antenna in signal quality then the 614 ever did with or without an external antenna.

Regrettably I only have a single external antenna. Due to the thick walls the supplier has installed it in our home; otherwise the range would be very limited. However they never mentioned the advantage to have two antennas.

It's just a in-house solution does it matter much that I only replace one default antenna with an external one in a different room? Or is is better to ditch the old external one and use the extension cable to mount one of the default Linksys antennas in a different room?

Joel

Reply to
Sjeng

On Fri, 08 Dec 2006 15:42:38 +0100, Sjeng wrote in :

You'd probably be better off replacing the Linksys with a router that takes only one antenna; e.g., Buffalo WHR-HP-G54. Recommended.

Reply to
John Navas

John Navas hath wroth:

The WHR-HP-G54 has two antennas for diversity, one of which is an internal PCB antenna at the top of the unit. See photo on the FCC web pile at:

It's the almost blank area between the push button and the external antenna connector. The "extra" antenna can be disabled in firmware (using DD-WRT) on both the Buffalo and Linksys devices.

[Hmmmm... I really don't like the LONG trace from the radio section to the R-SMA connector on the WHR-HP-G54. G10 is rather lossy.]
Reply to
Jeff Liebermann

On Fri, 08 Dec 2006 10:42:10 -0800, Jeff Liebermann wrote in :

My understanding and experience is that the WHR-HP-G54 firmware favors the external antenna. Otherwise, it wouldn't make sense for Buffalo to sell higher-gain external antennas. ;)

Reply to
John Navas

Buffalo could probably sell it without an external antenna as the internal antenna PCB works well enough. For example, the Linksys WRT54GC:

has an internal PCB antenna, an R-SMA jack hidden under a hinged panel, and is delivered with no external antenna (to save perhaps one dollar). Works well enough, but adding an external antenna does help the coverage considerably.

Another common question about the WRT54G antenna system is which antenna is "left" and which is "right" in the setup. The answer is that the designations are from viewing the back of the router.

Reply to
Jeff Liebermann

Jeff Liebermann hath wroth:

Oops. I got it backwards. WRT54G right and left are looking at the

*front* of the router. (So much for my photographic memory).
Reply to
Jeff Liebermann

Well thanks for the replies... The point is that I haven't seen the Buffalo routers for sale in the Netherlands and I've just bought the new WRT54GL... The range of the new router is acceptable (not really good) as is, so the point is: is it sensible to connect the one external antenna that I've got (by replacing the connector), or is it better to stick with the standard antenna's and forget about the old external one?

Reply to
Sjeng

If you have a GL put DD-WRT on it and you can play with which antennas do you the best job..

Adair

Reply to
Adair Witner

In my opinion, the radio section of the WRT54G/GS/GL are not so wonderful. Adequate, but not great. I compensate somewhat by cranking the tx power up from the default 35mw to about 100mw.

Leave the WRT54GL unit alone and get an adapter between whatever external antenna you currently have and the R-TNC on the WRT54GL. From your original posting, you claim to have a DLink AN24 antenna. My guess it's an ANT24-XXXX where XXXX is any one of 10 different models. Could I trouble you to properly identify what you currently have? However, it's not terribly important as all the DLink antennas use R-SMA connectors. So, what you need is an R-SMA jack to R-TNC plug adapter. This adapter usually comes with most replacement antennas, but can be purchased on eBay:

Lots more. That should allow you to use whichever antenna you have without butchering the WRT54GL.

Reply to
Jeff Liebermann

At my mother's house, I had a spare 5 dbi omni on a short cable and hooked it up to one side of her linksys WRT54G and got improved reception. I left the other antenna in place. There is no choice availible for antenna selection in the stock firmware for the Linksys. Still, it seems to work it out more or less with it's diversity antenna selection. Technically, I understand that it's not quite right this way, but it worked.

It was just temporary to get reception in a distant room, while I was visiting. But it made the difference.

Here in our community system, I've got a panel antenna hooked to one side of a linksy WRT54G. Again, it's temporary. I will pull it soon and put in a Buffalo router, but for now, the Linksys here is also working fine with the stock antenna on one side and the 12 db antenna (on a long low-loss cable) on the other. I got about a 6-10 db improvement when I put the high-gain antenna on. Some of that is from better positioning with a remote antenna.

So yes, you can do it with one antenna on the Linksys and it will work. Two matching antennas are not needed. Still, to make it work correctly with one, I understand that it's best to turn off the other antenna. To do this, you need to install a different firmware (DD-WRT for example) on the linksys that allows for antenna selection. Then you can turn the weak antenna off so the radio does not "see" it.

I read somewhere that you still want to leave the "dead" stock antenna connected in order to "terminate" the line or "balance the load", or some such thing.

Steve

Reply to
seaweedsteve

Actually, hearing from Jeff that the Buffalo also has a second antenna and, I presume, a diversity system, it makes me wonder.

When Buffalo sells you a single higher gain antenna for their router, are you supposed to turn off the internal?

Or does it matter much? I'm guessing that they don't expect you to know or do anything about the hidden internal. And I can't remember if their stock firmware has an antenna managment section.

Steve

Reply to
seaweedsteve

"seaweedsteve" hath wroth:

If you disable one antenna in the firmware, it doesn't matter what you do with the unused antenna port. It does nothing, goes nowhere, has no effect. No need to terminate it.

If you do NOT disable the unused antenna port, there's a small chance that diversity reception will select the wrong antenna. See the golf course case study at:

Reply to
Jeff Liebermann

"seaweedsteve" hath wroth:

Good question with no simple answer. My guess(tm) is that the internal antenna should theoretically be disabled, but if it's left enabled, it doesn't do much good for diversity.

Diversity reception works to help solve frequency selective fading. That's where you have two paths from the xmitter to one of the receive antennas that are 180 degrees out of phase, resulting in cancellation. That usually happens only in a highly reflective environment as commonly found indoors. Outdoors, there are fewer opportunities for reflections and multipath.

Diversity reception works best if the antennas have roughly identical patterns and roughly identical gains. That's a fair approximation of the Buffalo router, with it's internal PCB antenna with about 2dBi gain, and a short coaxial external antenna with the same gain. No problems. However, if we replace the external 2dBi rubber ducky antenna with perhaps an 8dBi panel antenna, the patterns and gains become radically different. Diversity reception fails as per the previous mentioned golf course example, especially when the client is moving in and out of the pattern.

If the external antenna ends up on a rooftop, but the internal antenna is still functional, then there's a *SMALL* possibility that the client will connect to the wrong antenna and end up with rather rotten connection. It will persist until the AP firmware declares the connection to be useless and switches to the other antenna. It can happen, I've seen it happen, but I guess(tm) that it's not a big deal and should not precipitate a mass reconfiguration of everyone's access point.

My two Buffalo routers have DD-WRT firmware so I can't check.

Reply to
Jeff Liebermann

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