External antenna for Huawei E220
If You have this little wonder for wireless broadband connection and living in area with poor coverage – read on! I have been trying to find a good spot for the E220 for two weeks with no luck, then decided to fix the things my way.
An important reminder!
By opening and/or doing any modifications to the wireless device you loose warranty immediatly. Furthermore, using non-certified radio communication devices and extensions can be illegal in your country. Information provided in this article is intended solely for educational purposes. The author is not responsible for any damages, losses or legal consequences caused by the practical application of these information.
Huawei E220 is built with an internal antenna, that means you can‘t attach an adapter to use third-party antennas commonly employed in areas with bad GSM/HSDPA coverage. Resources on the web stated there is a hidden connector inside the device. 
Further inspection of the cover proved that there is a hole preparation above this socket. Unfortunately, measurements have shown this jack is not wired to the GSM module. (red circle on the photo)
During my experimentation with a unipole GSM antenna attached to my roof, I accidentally touched the internal antenna‘s metal resonator (red arrow) with the lead wire. The module immediately started communicating with the network, and this was also audible on my stereo nearby that was turned on (loud). The actual wiring used was a cut-off WiFi pigtail that fits in the FME jack on the external anntennas cable.
When I tried to disassemble the device, I broke the „safety pin“ inside, which is in fact a screw holding the two pieces together. This screw can be accessed after removing the top cover (the one that has a bump for the LED indicator). This way one could open the device with enough care and thus leave the warranty untouched.
An important part is the ground connection of the RF cables shield/braid. It should be attached to the metal casing of the GSM module (green arrow), using cellotape is effective. Grounding wire MUST NOT touch the HOT wire attached to the metal strips of the internal antenna. Their shorting can cause damage to the module. Using foil shielding over the insulated wire connection and the cases top part fixes RF leakage.
I assume using directional high-gain antennas with the device can further improve the achieved signal rates.
UPDATE
I have taken a few shots of the disassembled and assembled modem. This mod works quite well for me, and the RF leakage is minimal. When the external antenna is removed, the modem is unable to operate due to the shielding.
2nd UPDATE
A big thanks to Waaahsabi who have posted a great link to an article showing how to attach an external antenna through the connector. Read on:
http://e220umts.blogspot.com
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Hi, I’m also working on rigging an external antenna to the E220. Could you explain your comment regarding measurements that indicate that the internal antenna connector is not connected to the GSM module? Is seems slightly odd that they’ve gone to the trouble of fitting a connector, provided a hole in the case to access it, but not actually connecting it (or am I being slightly naive). A link to the relevent website/forum would be very useful.
Thank You for commenting Kevin. The explanation is that I could not detect any RF signal on the center pin of the connector when the device was operating. But there is a possibility I have damaged it when trying to attach an MMCX plug. Of course the jack is not MMCX, so far I could not identify it. However I have seen a similar connector in a Motorola V235 cell phone, so it is some sort of GSM connector. Anyway, the internal antenna connection works well for me :)
Can you explain the comment ‘using foil shielding over the insulated wire..’. thank you.
Hi, thanks for the info, I want to have a go at this. I have already separated and broke the case…doh should have read this first :) . I am unsure of what type of antenna to go for and which parts of the wire to attach. Any chance you could put up some pics of your finished device?
I’m kinda inclined to (if I follow you right) go buy a G3 antenna (like one of these http://www.antennas-online.co.uk/catalog/catalog_desplay.php?CallCatalog=3G)
snip the connector off then attach the inner part to the part with the red arrow (as your pic) and the outer to the part with the green arrow.
let me know if I’m seriously misguided here.
anyway thanks for the most useful info so far on tackling this problem.
Hi Paul! I recommend attaching a short pigtail ending with some kind of connector, rather than wiring an antenna directly - FME male is recommended because most external antennas connect with FME females. However mine is somewhat different type (it’s a regular WiFi pigtail) it mates with a FME female. This way You can attach and remove different antennas without opening the device. I use a regular GSM unipole with magnetic stand. YAGI antennas or any kind of directional one would do better. Native 3G antennas are available too and they’re worth to try. Good luck!
Have you got any tips on how to remove the top cover? So as to open the device without breaking the safetypin?
You might wanna check this out here, they even got a list of items needed to use an external antenna “properly”, it seems you just have to plug a pigtail into the hole on top to access the external antenna port…
http://e220umts.blogspot.com/
maybe that stuff there works too.
Thanks Waaahsabi, the article You have posted is fantastic. I recommend it to everyone.
Hi, You could get one of those adapters here http://www.infoferenda.eu/
thanks mate i owe you a beer!!! temporaly taped the coax on tonight[thinking about arldite them in place] signal strenth is marganally better, but ive got it connected to a status tv/ fm caravan ariel…………miss guided i know……..lol , but im getting hspda signal at midnight on three. co.uk . for any one on three uk try using “tmobile web and walk manager ” software [create a new default profile] it works better than te three software …………cheers
Can i use this process with my HUAWEI EC325 NIC USB modem too Pleareply me soon!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Well, I haven’t heard about the EC325 before - the case looks the same. If the modem has a similar internal antenna like the 220, it should be of course possible to attach a cord leading to an external antenna. Maybe you could even use a general GSM antenna, the CDMA band is quite close to it.
From december of 2008 we have pretty good EDGE coverage but I still use the external antenna solution - now for almost 18 months! The modem doesn’t have to work so hard, the signal ratio is maximal and I have no interference in the audio systems.
Please, if somebody has the article from at e220umts.blogspot.com, upload to somewhere, or send it over e-mail to me please! That website seems to be deleted.
Hi,
After a lot of searching I found the connector called a Huawei-crc9
at
http://www.rfsupplier.com/advanced_search_result.php?keywords=crc9&x=39&y=12
Hope this helps