Modding DSE XH1153 (V1 802.11b USB) for ext antenna
Hi again to everyone
I'm trying to figure out a way of doing some antenna testing while moving about, so I need a wireless card that can take an SMA cable... I don't feel like modding my laptop's existing pcmcia card, but I have this old DSE USB one that I don't use for anything anymore, and was hoping it would be moddable just as a PCMCIA would... But looking at the board, it's not clear where the actual patch antenna is.. On the underside there's a lump (connector?) that appears to be connected to a chip labelled ANT1 via a couple of SMD capacitors.
Found a datasheet for the ANT chips http://www.staratech.com/docs/hF/NI_NBANT2G4V03.pdf. Turns out they're surface mount 1.2dBi antennas. The centre pin is the input... So maybe this makes it a bit easier. The lump on the other side connects through a capacitor and inductor to the centre pin of ANT1.. so maybe it's safe to assume that is an antenna connector of some sort.. but it's very small. Maybe similar to the kind of connector some GSM cellphones have on the back?
The lump on the other side connects through a capacitor and inductor to the centre pin of ANT1.. so maybe it's safe to assume that is an antenna connector of some sort.. but it's very small. Maybe similar to the kind of connector some GSM cellphones have on the back?
This is exactly the device I modded about 5 months ago - Gave it an N connector.
In the 2nd image, to the top left is a metal connector.......unsolder it. It needs to be taken off as it appears to be a test point for a special connector and switches the output to those little blue antennas on or off (on one of them anyway.)
Now, where the thing used to be, is a tiny thin track, find a good spot to solder to and solder the center of the coax to it.
Take a file, and file a big part of the ground track and use lots of flux to get solder to stick to it, and then solder the shield to this.....Voila! - You now have a modded card and the other antenna will still work in diversity mode.
If you are rangi like me, you can run the shield around the other side of the board and solder it to the big metal case on the opposing side.
Drill a few holes in the pcb in places where is doesn't matter and cable tie the coax to it - It needs LOTS of cable relief
I happened to have a 1 metre long reverse sma to n type cable and cut it in the middle - This was an LMR195 equivalent cable.
Be careful with the centre core of the coax, Once soldered, you need to be really careful with cable reliefe otherwise the slightest bend and it will rip the track right off - I know, you should see how many times I have resoldered the tracks to make it work again.
I guess I'll just pile on some hot glue.. or maybe aryldite to hold it down
Are you sure that the actual onboard ceramic antennas shouldn't be desoldered instead? I can see there's some components between that little 6 leg thing and both the SMD antennas.. Are they not necessary?
What sort of performance have you got out of it anyway? I'm just going to be using it to test my 19dB parabolic antenna when it arrives...
I have been using it to test links. Once the antenna is aligned, I just use an access point in client mode.
It doesn't give a noise figure which sucks, but apart from that, all ok
This is what we started to use when we set up our some client networks in CHCH over two years. http://yobbo.co.nz/belkin.htm
With these, we had to remove the external antenna first which gave us a positive location to solder.
We used to run a couple of USB ext leads with a USB repeater and install the antenna over 10M away from the PC, is very cool concidering how cheap you can do it for.
Yes the Belkin USB single or dual aerial wifi's are very easy to mod. To make it look even tidier I inserted a BNC connector into the housing where the aerial was and solderd Low loss cable from the PCB to the connector.
Yeah but these DSE ones don't have external antennas, they have internal SMD ceramic diversity antennas. As I understand it, the mod to mine has to be done before the components connected to the SMD antennas for some reason. Oh well. I'll try a few configurations and see what works.. Post back next weekish when I've tried.
Thanks for all the help... Geez I wouldn't attempt this if you're new to soldering though, those connectors are TINY! But it works. The Araldite ran quite badly before drying, so it's all over the bottom of the card, but it still works fine. I've also discovered how sturdy the card is, I dropped it in a puddle yesterday when I took it out of the car, still fine. And yes, it's happy being left on the carpet too
Well, I will give you 10 out of 10 for effet. Good on ya for daring to be dangerous. Looks as ruff as some of your first equipment.
I know you will be playing with the real toys in years to come eg: High power client & AP cards, amplifiers and lynix systems.
It is amassing what a small card can do. We had 6-8 km links with a 24dB Parabolic Dish & a USB Belkin card. There are a few Yobbo users still using this setup. Not as good as some cheaper PCI cards, but very fexiable with the USB to plug into any PC
Cheap Cheap Cheap, that is all I can say.
You are lossing out as you say the power output and no doubt receive sensitivity.
Bring on more modding Wireless Equipment to make it suit us.
Modding DSE XH1153 (V1 802.11b USB) for ext antenna 
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