Intel 4965AGN antenna question

[sethypoo26]

Hello, I have a Thinkpad T60p currently with the Intel PRO wireless 3945ABG wireless mini pci express card with two antenna ports (main and aux). I also have a sierra wireless wan minipci express card (that i dont use) which also has two seperate antennas/ports. I am looking to upgrade to the Intel 4965AGN mini pci express card so i could have access to wireless-n. However this card has 3 ports for antennas (1,2,3) I have researched and could not find much information on main and auxillary and the 1,2,3. I was looking for information and mainly wondering if anyone knew if I could take out both my current cards, put in the 4965 card and use the 2 the 2 antennas already attached to my current card, as well as 1 of the sierra card's antennas to plug into the 4965 card. Would this work? where would I plug the cables? would there be performance problems?

[SHoTTa35]

your idea would work just fine. The cables can only go in 1 place so plug in the normal first 2 into 1 and 3 and then plug in one of the ones from the WWAN card into port 3 on the 4965.

(don't forget you'll need Zender's BIOS hack also)

[sethypoo26]

What is Zender's bios hack?

[Blue Thunder]

Zender's bios hack allows you to install and use what IBM/Lenovo deem to be "unauthorised" wireless cards, which would otherwise prevent the computer from booting. There was a thread somewhere around here with all the details, but I can't seem to locate it at the moment.

So I'm assuming that since SHoTTa mentioned it, it means that the 4965-ABGN is "unauthorised" and will prevent booting when used in a T60p. Kinda sucks as I was thinking about installing an N wireless card, but I'm a little nervous about having to flash the bios...

[hellosailor]

IIRC the Sierra card is for cellular wireless conections, which are a different frequency from WiFi. So plugging the Sierra antenna into the new Intel WiFi card will gain you nothing, you would be better off leaving the third option not connected.

Offhand, IIRC, the Intel card uses diversity antenna switching, it will automatically switch to the antenna with the best signal so if you have one dud (the Sierra) connected, it will simply waste overhead time and power sampling the signal from a wrong antenna. On the other hand--you probably could extend that out to an external antenna connection, and use that to great advantage.

[sjthinkpader]

I bought a few Foxconn WiFi antennae and installed one along the left edge of the LCD about midway in my T60. It works fine.

After changing from intel a/b/g to Atheros a/b/g/n card, I had to remove and reinstall the AC utility.

I also tried a few Hitachi WiFi antennae in A31, R51. The 3rd antenna went in the A31 just to the right of the Ultraport at the top. In the R51, the 3rd antenna went in the left edge about midway from the top. This Hitachi antenna looks very much like factory antennae in T43 , R51, R52.

In a recently purchased X61s, the3rd antenna was already present from the factory.

[bill bolton]

Kinda sucks as I was thinking about installing an N wireless card, but I'm a little nervous about having to flash the bios...

I have a 4695AGN card in a T60 and it works fine using Zender's modified BIOS.

Cheers,

Bill B.

[bill bolton]

So plugging the Sierra antenna into the new Intel WiFi card will gain you nothing

While the WWAN antenna is not optimised for 802.11n operation it doesn't mean it is totally ineffective at all for 802.11n use, and it is certainly worthwhile trying.

Cheers,

Bill B.

[hellosailor]

Bill-
The crux of the matter is that cellular data systems are running around 1.8-1.9GHz while WiFi is running at entirely different frequencies, typically 2.4GHz or 5GHz.

The corresponding wavelengths are:
162mm (cell)
125mm (2.4G)
60mm (5G)

And the problem is that the cellular antenna will be about 1.3x the first WiFi wavelength and 2.7 times the latter. Antennas that are not tuned can often do more harm than good--because they will bring in whatever NOISE and interference is on the odd frequency that they are tuned for, without being able to bring in ANY of the correct signal. Generally, antennas are tuned (cut) at resonant lengths in terms of whole, half, or quarter frequencies, loosing effectiveness all the way.

You're right, it MIGHT not hurt. There are ham operators who have used wire fences, aluminum lawn furniture, and even light bulbs as antennas--and none of those are "tuned" properly either. But as anyone of them will tell you--none of those random events can hold a candle to aproperly tuned antenna. Sure, the cellular data antenna might help. And I might get struck by lightning, right after I go out to buy the winning Powerball ticket.

Odds? I don't think so. Why screw around when it is so much simpler to use the right antenna? Or, if you're really brave, prune down the cellular one to a WiFi length.

[bill bolton]

The crux of the matter is that....[

... the"tuning" of antennas that go into laptops, and similar kit, is fairly nominal at best.

Cheers,

Bill B.

[hellosailor]

Bill, I don't understand how or why you would say that. There's no need or reason for hand-tuning of antennas in commercial products, it is just "do the math" and then build them. The builder knows the specific frequency range that they are going to use, runs the numbers, and orders the antennas to match. Do they hand-tune them? Of course not, the tuning is done at the time of design. (And then, I'm sure the forensic engineering accountants will come back and tell them how much shorter they want it, because every mm adds cost.)

With commercial production standards, that's all the tuning these would need--and they do get it.

[bill bolton]

Bill, I don't understand how or why you would say that.

That's already quite clear!