The 511 is based on Atheros' AR5001X+ "Combo" WLAN chipset. This is essentially the same chipset used in NETGEAR's WAB501 802.11a/b adapter (and pretty much all 802.11a/b Cardbus adapter products), but with an AR5212 Multiprotocol MAC/baseband processor instead of the AR5211 chip used in the dual-mode WAB501. Figure 1 shows an internal view of the card.
Figure 1: The innards
Contrary to some reports, Atheros-based dual-band 802.11a/b CardBus adapters cannot be flash-upgraded to tri-mode a/b/g operation, because the 5212 chip is needed to provide the "secret sauce" for 802.11g.
Nor does using the WAG511's driver with a WAB501 (or any other Atheros-based 802.11a/b card) make it operate as a tri-mode adapter. You can, however, use the WAG511's utility with a WAB501 card, although the utility will identify the WAB501 as a WAG511 on the utility's About tab.
Tip: I previously had installed a WAB501 in my test notebook and found that I had to go to XP's Add / Remove Programs utility and uninstall the WAB501 in order to get the WAG511 to install properly.
Eagle-eyed buyers of the WAG511 may notice that it has the same FCC ID as the WAB501. At first I thought this might just be a mis-print, but then started to think that the conspiracy theorists might be right - that the WAG511 is just a re-labeled WAB501! A quick check with NETGEAR, however, brought the answer that the MAC/baseband chip substitution described above is considered a "permissive change" in FCC jargon. This allows the same FCC ID to be used - saving the expense and delay of submitting the modified design for a new round of testing.
Similar to its 802.11a/b sibling, the 511 requires a CardBus, not a PC Card slot. This is because CardBus is a faster 32 bit bus vs. the slower 16 bit PC Card standard and is needed to support the card's higher data rates.
Tip: Since CardBus and PC Card products look virtually the same, you'll need to check your laptop's PCMCIA Adapter entry in Windows' Device Manager to see whether your machine supports CardBus. Proxim has a handy CardBus FAQ (PDF format) if you need more info.
The adapter has two LEDs, which blink in unison most of the time, with rates varying according to network activity. You get an alternating blink pattern when the card is searching for an Access Point or other AdHoc client (when in AdHoc mode, of course). The LEDs are at the end of the fairly large antenna housing which will block the CardBus slot above it in a multiple slot laptop. The card has no provision for attaching an external antenna.