[POSTED TO alt.internet.wireless - REPLY ON USENET PLEASE]

In <u7jfk1pcp39stmckisg4dpgsve3l7eots4@4ax.com> on Sat, 08 Oct 2005 07:05:15
-0700, Jeff Liebermann <jeffl@comix.santa-cruz.ca.us> wrote:

>On Sat, 08 Oct 2005 11:37:10 GMT, John Navas
><spamfilter0@navasgroup.com> wrote:
>
>So much for new and improved.

My guess is new and cheaper (in the negative sense of the word).

>>* Range is significantly worse than the original WG511 (v1), on the order of
>>10-20% less.
>
>A bit of math in antenna gain, tx power, and rx sensitivity.
>Rounding off a bit.
> 12dB is 25% of your range.
> 6dB is 50%
> 3dB is 75%
>1.5dB is 87.5%
>Therefore, for you 20% loss in range, there is about a 1dB difference
>between the v1 and v2 incantation. I have no way to tell if it's in
>receive sensitivity, transmit power, or antenna gain. My guess(tm)
>would be antenna gain. 1-3 dB variations in product lots are all too
>common.

These results were consistent with two different samples of each card.
(That's not statistically valid, but better than just one of each.)

>>In some locations where the original WG511 (v1) can connect and
>>hold a weak signal, the WG511v2 is too unstable to be usable
>
>Different chipsets have different algorithms for dealing with
>reflections. If the weak signal is the result of going through walls
>or floors, you're really measuring how well the receiver can handle
>multipath. How well does it work in a line of sight and minimal
>reflective environment?

These results are consistent over multiple environments, both with and without
walls and floors.

>The v1 to v2 transition suggests a change of vendor so that two cards
>may be completely different inside. Could I trouble you for the FCC
>ID numbers so I can look at the inside photos on the FCC web pile?

The cards I currently have:
v1: PY3WG511-F
v2: PY3WG511V2H1

Google suggests that there are at least 5 versions of this card:
PY3WG511 Intersil
PY3WG511-F Intersil
PY3WG511V2H1 Marvell
PY3WG511V3 Atheros
PY3WG511TV1H3 Atheros
That last is probably the WG511T, a distinctly different Netgear product, and
I'm thinking the prior one may be as well, leaving the first three as members
of the base WG511 family, with two chip vendors. My guess is that the Marvell
implementation is cheaper but not as good as the Intersil implementation.

>>* Stability of the WG511v2 is much worse than the original WG511 (v1), to the
>>point of losing connections even in strong signal conditions.
>
>Ouch. Now, that's bad. When that happens, check whatever utility is
>supplied with the card for the connection speed. If it has slowed
>down to 1-2Mbit/sec, then the card and/or it's driver is doing a very
>bad job of handling interference. They're suppose to slow down or
>stop in the presence of interference, then speed back up when it goes
>away. Some drivers do not recover very gracefully. If the speed
>stays fairly high, then that's not the problem.

The speed stays fairly high (36+). Signal strength at the PC Card is 6-8
balls out of 8 on the Netgear monitor.

There are two access points in the area (inside a public library) with
overlapping coverage, roughly the same signal strength, and the same SSID.
There are no other obvious sources of interference, not even any other
apparent wireless clients when I was testing. My guess is that the card is
sporadically trying unsuccessfully to switch access points (roam).

>>These observations are based on extensive careful testing of more than one
>>sample of both types of cards in multiple locations with the latest Netgear
>>drivers under Windows XP SP2 on an IBM ThinkPad T30.
>
>What access points or wireless routers were you using? Just curious
>if you're mixing chipsets.

Other than the D-Link home network, all the others are unknown hotspot
hardware.

>>Accordingly, my recommendation is for the original WG511 (v1) over the
>>WG511v2, which didn't even perform as well as other (non-Netgear) 802.11g
>>cards I've used and tested. Easy way to tell them apart:
>>
>> * The original WG511 (v1) has a silver antenna bulge.
>>
>> * The WG511v2 has a black antenna bulge.
>>
>>See also <http://kbserver.netgear.com/products/WG511.asp>.
>>
>>Although the original WG511 (v1) may be hard to find new, good used ones are
>>readily available on eBay (as of this writing) at bargain prices.

--
Best regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES:
John Navas <http://navasgrp.home.att.net/#Cingular>