I’ve been using these cards for about a month now and they seem very tempramental.. when using them in station-wds mode these cards seem to have a mind of their own. Some work some don’t. I just wanted to get some feedback from the people who are using these cards and how well they’ve performed..
Will keep up with this topic and give you my feedback as I have just started to build and deploy links with these cards. I have great hope for these, and hope to overcome some inherent problems that 900 poses. So I understand your setup so we can help each other:
Are your SR9s already deployed? – 900 is a band with a mind of its own
Have you run them in a controlled environment? – I have, and had a stable bench setup working. However, I have seen what could be perceived as odd behavior. I wrote that off as having too much signal too close. I finally put in attenuators which brought the signal so low (-90dbm) that it probably introduced instability.
The performance of my bench test links has been a pleasant surprise. I was able to get great performance. I also was able to power them down and come back later and they actually came back up and performed as expected. This occurred over more than a weeks time, but of course need more proof than that. I attributed any temperamental behaviour to a lack of understanding on my part. I hope that was the case since ultimately I was able to replicate the links several times, and (wow) actually got a 3 radio ‘repeater’ type link to actually work properly.
I am sitting here looking at several complete SR9 based links. My experience with 900MHz systems is to forget analyzing links as you would on 5GHz. 900 brings a whole new set of issues. Works too good, hears interference too well, works in places you would never try to get signal before (therefore tricking you into thinking all is great). Thats why I wonder if you have them deployed. My gut tells me that the radios are going to be OK once you get used to their idiosyncrasies. Thats why I am sure going to install a test link tomorrow (Sunday) to start the acid test. Its hard to differentiate instability introduced by RF (especially on the bench) versus this CF of a mode called WDS. I know how WDS works, how it came about, why it became a feature in radios that vendors exploited by implying they had a ‘feature’ or functionality others didnt. Only once have I seen utilization of WDS actually listed as WDS. WDS seems to be a desirable functionality introduced by an oversite, somebody intuitively thinking it might be nice to have sometime ‘for future use’, or simply a mistake exploited ingeniously by a savvy developer.
For me, the appeal of the SR9 is its unique capability to operate in modes never before used on 900. The concept of a 5MHz channel on 900 plays well with the inherent troublemaking characteristics of the band. However, one forum participant in another thread stated that SR2s (I believe) transmitted a 5Mhz signal, but listened on 20MHz. 
That would really suck and eliminate one advantage I had hoped to leverage, operating in a quiet sliver of the noisy band. Lets hope its not true. Listening to the whole band would…
So, Wildbill, I am going up on a 300ft building tomorrow and deploying an SR9-based link to identify characterisics of these cards. Ya think I am going to hear it at 18 miles in the very noisy urban spectrum? I think that is a definitive ‘acid test’. I am pushing the envelope very far, but if it plays out the way I anticipate, it will answer a lot of questions. Otherwise I will have to shorten the test path which will still yield much valuable info. If it works, it would be really sweet since coincidentally the far end would be very close to this very PC. 
I am anxious to hear more of your experience with them as well. So far, I have deployed other MT/Atheros based links in essentially identical configurations except for band, with better than expected performance and stability. Getting used to some of the anomalies with the SR9s like using the 2.4 frequencies to set channels is just one problematic aspect of the card that should force us to remember that its immature and definitely bleeding edge. How about the size of the card? Only fits in certain slots which fortunately hasnt caused me a problem yet, but is easy to see how it will at one point. Wonder if that is introducing any side-effects? Utilization of 2-SR9s in a box is one sticky problem, if you are crazy enough to try it. At this point, making that work using routerboards, would require 500’s with daughtercards to fit them both in.
Will let you know what happens with my acid test link. Good luck with your links and let me know how your links are doing.
I have gone on long enough. I know this topic will soon be generating a lot of ‘noise’ to say the least…I can only hope it delivers many Mbps to my first location and let the noise begin .
according to discussions at MUM, the SR series (2,5, and 9) transmit as low as 5mhz, but never listen smaller then 10mhz… so even on 5mhz channels, you are listening on a 10mhz band, but you’re only burning spectrum when you transmit, not perfect, but the 5mhz channel most definitly still has it’s uses..