Jim - If you really want an independent comparison, get me some of these cards. I test 802.11 h/w in some of the harshest conditions out there (some till failure) - I have no loyalties to any card company other than I buy cisco cards (but not their routers) simply because they test best and work best in my real world scenario. I've also been doing this enough years to tell when a manufacturer makes a "special" card that's definitely going to exceed performance. Different solder in the SEM metallurgy - extra test pokes from "tweaking" - and the number of scratches left on the pins/fingers from insertion/extraction - all tell a story of a product which was either made with all the rest, or taken off the assembly line to be "enhanced" for testing submission.
Everett > > the demarc (really zcomax!) and Senao/Engenius cards are about the same. > > If you want real RX sensitivity, buy something newer than either, like > a good quality Atheros card and run it in 11b mode. Kicks as* on > anything Prism2.x-based, and the whole Prism-thang is about to be > yesterday's news now that Globespan-Virata purchased the > not-yet-rotting corpse of Prism (it was far too expensive for a > commodity market.) > > Heck, nearly any new chipset (AMD, Broadcom, etc) with a decent LNA in > front of it can come close to the claimed rx sensitivity of zcomax or > Senao. > > And yes, PAs run hot when they're throwing down a lot of power, and hot > PAs distort the signal and worse. > > The hunch about different receivers is misguided, the baseband for both > the Cisco and Prism-2.5 are essentially the same. > > The concern about vendors over-specing the datasheet is well-founded, > however. I saw a vendor the other day claiming 268F from his "outdoor > bridge" which was little more than a Ubicom + Senao 200mW combo in a > cheap plastic box. As always, YMMV. :-) > > Jim > > ob disclaimer: My wife sells both Intersil and Atheros-based designs > manufactured by Senao, and I've gone a few rounds with Tony from Demarc > more than once comparing the two designs. > > On Sunday, September 28, 2003, at 3:54 PM, [EMAIL PROTECTED] wrote: > > > <snip> > >> roddog wrote: > >> > >>> O.K. So you want a bad as* card for wardriving? > >>> What you need is a Senao/Engenious? card with 2 antenna ports on it. > >>> These cards have a better sensitivity than just about anything out > >>> there > >>> next to Demark > >>> and they also have 200mW of power which is the most powerful out > >>> there. > >> > > > > Brian Lloyd writes next: > > > >> A couple of comments about the Senao: > >> > >> As for sensitivity, the Senao card has better *published* receive > >> sensitivity specs. It seems pretty good but I am not sure it beats > >> the Cisco for RX sensitivity. > >> > >> TX power does indeed seem to be about +23 dbm. > >> > > <Brian's notes on antenna connection info deleted below here> > > > > I agree with Brian - I've now had a chance to get a couple senao's on > > my > > bench, and while my 2 cards are _not_ a valid statistical sample size > > (which > > I clearly emphasized to the customer who handed them to me), I have > > noted > > that both cards lacked the receive performance of the aironet/cisco 350 > > series cards. They did both deliver the +23 dBm into 50 ohms (but > > most all > > of my cisco 350's exceed their +20 dBm spec by 1-2 dB). given all > > this - the > > 1-2 dB of extra xmit power compared to a typical cisco 350 weighed > > against the > > loss in receive (not enough samples to say definitively, but it's alot > > more > > than the benefit of the transmitter) doesn't justify their use in > > MARGINAL > > links as a better alternative. They still seem to be a great > > all-around card > > for NORMAL links, and CAN be the best bang for the buck in many > > situations > > that don't call for the absolute best money can buy. I hope they > > force cisco > > to make a 200 mW "360" card! It's the best part about market > > competition! > > > > My hunch is that it was simpler and cheaper for senao to make a +23dBm > > card > > with a so-so receiver than a +20dBm card with a great receiver - > > besides, > > marketing will LOVE being able to say "twice as much POWER" - when was > > the > > last time you heard a marketing hype "6 dB better code to noise > > ratio!"?? > > > > As a BIGGER note - (again - keep in mind 2 cards does not a statistical > > sample make) - placing them inside a calibrated RF anechoic + > > temp/humidity > > chamber resulted in wider variance near the high end of their specified > > operating temperature (60c). The performance in the unspecified area > > above 60c was substantially poorer than a comparable cisco card. But > > why > > is 60C so important? > > > > Once again - if your card is kept at 22 deg C inside your house, > > you'll most > > likely never notice - but if it's outside on a 100 deg F day - inside > > a box > > on a pole in the sun and your link margin drops below zero - it's a > > big deal. > > NOWDAYS, EVEN THE PCMCIA SLOTS IN LAPTOPS CAN GET TO 60C! I just > > stuck a > > micro-thin type T T/C in between my 2 pcmcia cards on the laptop I'm > > using > > to write this - 23.2 C room temp, 56.8C in between the cards! (and > > this is > > a PII/350 not some 3.0G PIV rocket laptop that has a 90 watt adapter!) > > Ever > > pull out the card and notice it's hot to the touch? Senao's spec > > sheet stops > > at 60C for their high power card. I'm just ~3C away from that temp on > > a 3 yr. > > old laptop! When my 2.0 Ghz laptop comes back from repair, I'll > > duplicate > > the "pcmcia slot temp" test on it. That thing is too hot for a "lap" > > sometimes. > > I can't imagine how hot the pcmcia compartment is! > > > > Cisco, on the other hand, rates their AIR-PCM35x series to +70C - AND > > THEY > > MAINTAIN THER PERFORMANCE SPEC. Through the whole temperature range > > and > > a little bit beyond. > > > > > > I'm not getting these numbers out of thin air - read the spec sheets > > in person > > http://www.cisco.com/en/US/products/hw/wireless/ps4555/ > > products_data_sheet09186a0080088828.html > > > > http://www.senao.com/service%20&%20support/Spec/NL-2511CD_PLUS_Spec.pdf > > > > (funny - senao's older cards were only rated at 50C - then 55C, then > > 60C ) > > > > If it seems like this bugs me - it does to a degree - It's not fair for > > manufacturers to make impressive glossy ad slicks that have numbers > > 99.99% > > of the population can never verify. Too many people make buying > > decisions > > on bad data - then wonder why things don't work. I've heard all too > > often > > "but the box said it would go 5 miles!" I guess it keeps customers > > comming > > though... > > > > Everett > > > > -- > > general wireless list, a bawug thing <http://www.bawug.org/> > > [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless > > -- > general wireless list, a bawug thing <http://www.bawug.org/> > [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless > -- general wireless list, a bawug thing <http://www.bawug.org/> [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless
