Re[ltp] placing the Ericsson 3G modem in an X301 with a Sierra Wireless LTE modem

Bjørn Mork
Thu, 31 May 2012 10:54:35 +0200

Elvair <> writes:

> Hey, listen I have another question
> We know that there are 6 antennas, 3 are used for WLAN card, gray - (MAIN=
) -
> tr1, white - TR 3, black - tr2
> What are the colours of other cable and what are they used for ? On sierra
> card there are 3 ports, AUX, GPS, MAIN, which cable should go to which po=
> then in x301 ?

The maintenance manual says red => MAIN and blue => AUX for wwan, and
that is how the Ericsson card was connected in my X301.  Now I believe
AUX on the Ericsson card is really the GPS connector, so I chose to

 red   => MAIN
 blue  => GPS
 beige => AUX

on the Sierra card.  You can see this on the pictures I posted a link
to. I think AUX on the Sierra card is really RX diversity, so selecting
an antenna on the opposite side of the screen from the MAIN antenna made
sense to me.

I have no idea whether that is the best configuration or not, or even if
there is any difference between the antennas (all 6 look alike to me).
But the above works very well for me.  Gives better reception on the 
2.6 GHz LTE band (B7) than the builtin antennas in a Huawei E392 stick,
having the exact same Qualcomm chip inside.

The Sierra GPS works a lot better than the Ericsson one, but that could
be due to radio improvements.  A lot has happened there during the 4
years between these cards.