CF-28 Wi-Fi notice - miniPCI 3A vs. 3B

I searched several times for this info, but didn't find it. Let me know if you find it elsewhere on the forum.

Anyway... If you're looking for a miniPCI wireless card for your mk2 or mk3 CF-28, make sure you get a miniPCI 3B (IIIB) form factor card! Don't get a 3A card!

What's the difference? Size - only about 10mm in fact.

From http://en.wikipedia.org/wiki/Minipci#Mini_PCI :
IIIA: 2.4 × 59.6 × 50.95 mm (Larger Y dimension)
IIIB: 2.4 × 59.6 × 44.6 mm (Smaller Y dimension)

I'll post some comparison pictures within a few days, along with a guide on how to tell the difference visually if the seller does not indicate the card's dimensions (and they usually don't).

The "inner" miniPCI slot is only large enough to accommodate a 3B card - if you try to insert a 3A card, it won't go all the way in - the adjacent miniPCI slot is in the way. The outer slot, on the other hand, will fit the card, but then you can't use the miniPCI Ethernet, as the internal Ethernet cable will not reach the inner slot. I know that I personally am completely unwilling to sacrifice Ethernet for WiFi.

I have a generic miniPCI Atheros card that I was really excited to install. You can imagine how dismayed I was when I found out it wouldn't fit. That sucks for someone like me, with tons of miniPCI cards, but in the wrong size.

Curiously, all of my Intel 2200 cards are 3A, but all of my 2100 (802.11b only) cards are 3B and thus fit in the slot. I wasn't however willing to sacrifice 11g support, particularly the WPA capability that goes along with it. Right now I'm using an 802.11g Broadcom 4318 card until my new Atheros 11abg card comes in.

-- begin off-topic rambling ---

The 4318 is a decent chipset, by the way - even if you're using Linux (like me). It needs firmware that can't be provided with the open-source driver for legal reasons, but it's easy enough to get that firmware (Debian package "b43-fwcutter"). Performance is about average given the magnesium shell. I'm using a self-installed set of antennas - one on each of the side covers.

At some point, I should do a comparison test with all of my 3B-formfactor cards, most of which are 11b-based.

 

For info, when I did the same mod on my CF-28 Mk3, I tried both an 'Intel PRO/Wireless 2915ABG' and an Atheros ABG card, both of which fitted fine.

I have one of the Intel boards here, it measures 44.5 so within the IIIB profile.
It's part model number is WM3B2915ABG

The reason for two boards was that the first did not seem to work. After I bought the second I realised my access point had crashed..

 

Some further research seems to indicate that Intel's 2200BG and 2915ABG cards indeed are made in both the 3A and 3B form factors.

rjenkins, at least you have two fairly nice ABG cards now