Antenna questions again

Live forum: http://rt2x00.serialmonkey.com/viewtopic.php?t=842

ropf

01-02-2006 23:42:26

Hi!

I've read all the topics about antenna mods an want do do this on my DWL-G122.

The G122 PCB provides place for two chip antennas but only one is mounted. Between them is a UFL connector. (I'm not really shure - there are other concektors for testing purposes out there - looking very similar to U.FL but incopatible)

The question now are
- How the device and the driver handle more then one antenna?
- What are the characristics of this chip antennas, wich impedance do they have?
- A u.fl connection should perform mutch better on microwaves than a soldered one. Is it true?

The options are now
- don't care about the mounted chip antenna, just connect a pigtail to the u.fl connector (if its really a u.fl) .
- the same but solder the pigtail to the unused place for the second chip antenna.
- use the u.fl connector but remove the original antenna.
- remove the chip anrenna and solder the pigtail on her place.

It depends from the questions above wich of these options is the best so i'll be glad about any answers.

With regards ropf

dimgr

14-02-2006 23:53:27

Hi!

I've read all the topics about antenna mods an want do do this on my DWL-G122.

The G122 PCB provides place for two chip antennas but only one is mounted. Between them is a UFL connector. (I'm not really shure - there are other concektors for testing purposes out there - looking very similar to U.FL but incopatible)

The question now are
- How the device and the driver handle more then one antenna?
- What are the characristics of this chip antennas, wich impedance do they have?
- A u.fl connection should perform mutch better on microwaves than a soldered one. Is it true?

The options are now
- don't care about the mounted chip antenna, just connect a pigtail to the u.fl connector (if its really a u.fl) .
- the same but solder the pigtail to the unused place for the second chip antenna.
- use the u.fl connector but remove the original antenna.
- remove the chip anrenna and solder the pigtail on her place.

It depends from the questions above wich of these options is the best so i'll be glad about any answers.

With regards ropf[/quote32itb8qp]


are you sure there are 2 antenna placements? I only saw on on mine. What you need to get is a U.FL/MHF pigtail. Mine is U.FL/MHF to RP SMA. All i did was to mount that pigtail then fit the 5cm cable in there then close the case , fill up the hole with some epoxy , attach my 5,5dbi omni and start scanning)
Sorry there are no inside pics

i get my stuff from here www.aerial.net

ropf

15-02-2006 03:37:11

Hi dingmr,
thanks for the fast reply

Yes, i'm shure about the antenna placements. I d'ont have a camera yet but found some pictures here[/urlmutt9lgp]. For comfort i will link some photos directly. For bigger Pictures just click on it.

Here is the g122 inside
[url=http://photos1.blogger.com/blogger/3591/2176/1600/Dlink%20dwl-g122-Foto1.jpgmutt9lgp][imgmutt9lgp]http://photos1.blogger.com/blogger/3591/2176/320/Dlink%20dwl-g122-Foto1.jpg[/imgmutt9lgp][/urlmutt9lgp]

And here is a modding suggestion
[url=http://photos1.blogger.com/blogger/3591/2176/1600/2a_MOD_Dlink_dwl-g122.jpgmutt9lgp][imgmutt9lgp]http://photos1.blogger.com/blogger/3591/2176/320/2a_MOD_Dlink_dwl-g122.jpg[/imgmutt9lgp][/urlmutt9lgp]

This is a u.fl connector. Please note the center pin
[imgmutt9lgp]http://www.m-o-r-i-t-z.de/wlan/anschluss.jpg[/imgmutt9lgp]

But on my board it looks more like this hirose ms-156 test connector
[imgmutt9lgp]http://www.latinsud.com/adm8211/conector1mini.jpg[/imgmutt9lgp]

Some people claim a u.fl pigtail working on the ms-156 connector but it doesnt really hold. Ok, filling the stick with epoxy mayby solves this problem. Cool idea!! Fitting a connector to the ms-156 disconnects the internal antenna. (see [url=http://www.hirose.co.jp/cataloge_hp/e35801678.pdfmutt9lgp]pdf description[/urlmutt9lgp])

Some questions are still open.
@ the rf gurus the internal antena is connected to the chip by some resistors or capacitors. I believe this is to fit the impedance. Is this necessary for a external antenna and how to do it right?
@ the driver developers the behavior of the chip with two antennas. Is it hardcodet in the eprom, do i need a driver pach or is it better to remove the internal antenna?

If i wrote somethin wrong please correct me. With regards
ropf

dimgr

23-02-2006 11:27:14

[img1dx2vfzm]http://img.photobucket.com/albums/v194/dimgr/dscn3637.jpg[/img1dx2vfzm]

Adisorn

27-02-2006 21:13:57

Hi,

I wonder how much gain did you get when just plugged in U.FL pigtail.
I didn't see any improvement when plugged in my U.FL pigtail to it. I also
have U.FL to RP-SMA pigtail but with 3dB antenna.

I think I may still have do HW or SW modification to it. I found these
pictures from the web. I don't know how to insert pictures in with
text yet? (maybe you can help me). Anyway I insert pictures as
attachment.

http//foro.elhacker.net/index.php/topi ... 51363.html

I haven't had time to try it yet.

Regards,
Adisorn.

MartLenn

30-08-2006 16:43:15

Sorry for bringing this old topic back in the public, but I just felt that I wanted to report about my experiments in modifying the GWL-G122. Since my device is rev C1 the pictures in the previous post doesn't directly apply. So I made a guess, and tried to perform the modification anyway.
I attach a picture describing the mods I've made.

Unfortunatly, this didn't give any increased performance. I'm pretty sure I've done the modification correctly - at least as far as I can measure with a multimeter. Before I did any soldering, I also tryed connecting a u.fl-connector to the miniport on the card. This didn't give any increase in performance eather. I both those experiments I've used a 9dB-antenna.

So the conclusion is
a) I did some of the soldering wrong, or
b) The rev C1 doesn't support an external antenna without SW modifications. (I run the original D-link drivers under winXP)

Is there anyone else who has tried those actions on a adapter with rev. C1? Have you made any progress?

EDIT See post below

MartLenn

01-09-2006 15:05:22

A small update. After some more testing I've realised that the mod actually does work. I post an image of the result after serious amounts of hot glue. Attached to the adapter is an ordinary D-link antenna @ 1.5-2 dB I'd guess( I got it with my D-link G520).

And of course, "transistor" in the prevorious post should be "resistor".

adso58

16-09-2006 12:07:10

I have a DWL-G122 C1, and a B1. I want to try to use an external antenna first in the C1.

Your pictures are very helpful, but I would like to know how you obtained the points you have to solder, and how do you know what resistor should be removed?

Are there any guidelines or tutorial? I can blindly follow your instructions, but I would like to know how to find it by myself )

Thank you in advance.

MartLenn

20-09-2006 21:28:06

I have a DWL-G122 C1, and a B1. I want to try to use an external antenna first in the C1.

Your pictures are very helpful, but I would like to know how you obtained the points you have to solder, and how do you know what resistor should be removed?

Are there any guidelines or tutorial? I can blindly follow your instructions, but I would like to know how to find it by myself )

Thank you in advance.[/quote2nsorv76]

Actually, my method was a good combination of trying to follow the previous posts, doing some measuring with a multimeter, and some pure guessing.

My hint is try to measure with a multimeter which parts that are connected.. It's for instance pretty easy to realize where the ground should be connected. The multimeter is a good tool for testing if your guesses are correct - before you do the soldering.

Removing the resistor was mostly a guess. In the instruction posted earlier this is done to disable the internal antenna. However I'm not really sure if that makes any difference. I guess that just soldering the + to the internal antenna on C1 should work as well. The only difference is that there will be some more resistance. If this is good or bad - I don't know.

Good luck with your modification! Please also document and post them here! =)

adso58

21-09-2006 11:10:13


My hint is try to measure with a multimeter which parts that are connected.. It's for instance pretty easy to realize where the ground should be connected. The multimeter is a good tool for testing if your guesses are correct - before you do the soldering.
[/quote2gsnfb0p]

Yes, the ground point is very easy to find, but the + point, I don't find where is connected using the multimeter, I don't know where is the + in the integrated antenna either. I don't know very much about antennas as you can see.

That's what is stopping me to start soldering, it should work because the board is exactly the same as the one from your pics, but I want to find that point by myself (and a bit of help, of course).

Thank you for your response.

Edit I have been trying to find a point that is connected with the + point you used, or the + point in the B1 model ( I have both), and I can't find any single point connected to your +. How did you find that point? What it should be connected?

Gussoh

08-04-2007 23:38:33

Hi! I think this is stil relevant. So I hope you dont mind if i bring it up again!

MartLenn's mod works for me. I get almost as good signal strength as with my D-Link DWL-G520.

[img282gop1c]http://www.sohtell.se/DWL-G122/front.jpg[/img282gop1c]

More pictures can be found on [url282gop1c]http://www.sohtell.se/DWL-G122/[/url282gop1c].

Thanks!

hack.rid

23-04-2007 22:02:46

hello!
im a proud owner of an dwl-g122 b1 sp please tell me what the best way is to solder an antenna cable on to the stick. im not very good in understanding english, im just a german.

do i have to remove the internal antenna(is this the internal antenna??)
PLEASE answer my questions on the image.


please excuse my bad english
thanks dude for scanning the stick ;)

thx. alot!

hack.rid

28-04-2007 17:38:58

infact noone ansewred me.... i post my ugly results...

works done but ive a problem the connection abborts freqently. well seen in netstumbler. i think the stick has a problem with my not "shorten" atenne.
please tell me your experiences.

hack.rid

07-05-2007 17:24:43

more pics

hack.rid

07-05-2007 17:28:28

morepics.....

please leave a comment !!!!!!

i need more tx power to reach my target ap... thats what i know NOW!!

i will bau a alfa usb adapter with 500mW this should be enough for my plans.

regards, hackrid

hack.rid

31-05-2007 15:33:12

bla bla bla

gusm

31-08-2007 10:28:43

Missing pics can be found here

http//wireless-zero13.blogspot.com/200 ... 2-mod.html

tesseract

09-08-2008 21:27:01

If you haven't had enough of this thread already I was wondering if anyone might lend a hand.
I recently purchased a D-Link DWL-G122 C1. Like most people I found that the antenna strength was terrible at best. I had already seen all the great pictures that people posted of how they moded their DWL-G122 C1 so I figured I would have no trouble doing that as well.
The problem is that my PCB board doesn't look like the ones posted here--or anywhere for that matter. I took a couple pictures of it--both front and back--and I was wondering if anyone might be able to point me in the directions of where I need to solder my external antenna connection on. I can't even find the built-in antenna!

Here's the front [img210q1dbu]http://img150.imageshack.us/img150/1480/frontsideiw1.th.jpg[/img210q1dbu][/url210q1dbu]

Here's the back [url=http://img151.imageshack.us/my.php?image=backzi9.jpg210q1dbu][img210q1dbu]http://img151.imageshack.us/img151/3708/backzi9.th.jpg[/img210q1dbu][/url210q1dbu]

And here's a different picture of the front [url=http://img150.imageshack.us/my.php?image=frontao7.jpg210q1dbu][img210q1dbu]http://img150.imageshack.us/img150/2002/frontao7.th.jpg[/img210q1dbu][/url210q1dbu]

Notice that the pictures get considerably large if you click on them. I hope that they are clear enough; it was the best I could do.

Thanks in advance to anyone who has any idea on where to go from here!

Kismet

02-11-2008 01:46:19

tesseract,

This is you antenna

[img23vu8wer]http://img353.imageshack.us/img353/6830/antennaxf5.jpg[/img23vu8wer][/url23vu8wer]


Just that piece of copper!

If you want to wire an external antenna,
all you have to do is remove some copper from the "painted red line" so that you isolate/create point A and B
(You can do it with a sharp cutter)

Then iron you wires on A & B.

Please give us feedback.
-----------
Dr. Ing. Kismet

Fiummy Lee fun