Ubit has two - one centered on 912 and one centered on 917. Be sure to
order the appropriate one.
Brian Rohrbacher wrote:
I just called for the info, but I need something now and might order the
ubnt one if I get someone to ship it today. So, as long as my center is
912-917 I'd be fine with the ubnt one? I think that will do.
Brian
Jack Unger wrote:
Brian,
Bandpass filters come in different band "widths". Some are full-band
filters that pass 902-928 MHz and some are single-channel filters that
are narrower and pass only one channel. The bandwidth of the two
Ubiquity filters are a little narrow to use across the entire band but
if you are using 912 or 917 as center frequencies, they should work
well. If you're using a lower center frequency, you'll need a filter
that has a bit wider bandwidth but which still attenuates the paging
frequencies a lot. The availability of good whole-band bandpass
filters seems to have deteriorated a bit in the last year. There are
more filters available but they seem to have poorer characteristics
and sometimes higher prices. I just looked at RFLinx and Hyperlinktech
and I am not happy with their current offerings. I did discover a
notch filter that is tuned to attenuate the paging frequencies while
passing the 902-928 frequencies. I don't know the pricing but if it's
priced reasonably then it looks like your best bet. Here's the link:
http://www.microwavefilter.com/2ghzRelocation.htm#ism
It's the filter at the bottom of the page. If you call them to get a
spec sheet and to check pricing, please share that info.
Thanks,
jack
Brian Rohrbacher wrote:
Thanks, Jack. Would installing this one
http://www.ubnt.com/cf.php4 be the correct move? Or is something
else preferred.
Brian
Jack Unger wrote:
Brian,
A -36 dBm signal probably won't destroy your receiver or permanently
desensitize it however your best bet is to get confirmation from a
Motorola rep. The signals you see at 928-930 MHz are from one or
more paging transmitters. These paging signals could easily
desensitize your AP receivers temporarily and cause a temporary
inability to hear incoming SM signals.
Since you appear to be using antennas that are external to your APs,
you can insert a bandpass filter between each AP and its antenna.
This will attenuate the paging signals and allow the APs to receive
SM's from further away. If the paging transmitters ARE the cause of
your apparent AP receiver sensitivity deterioration, then the
bandpass filters should be helpful in reducing the frequency of
occurance of the problem.
jack
Brian Rohrbacher wrote:
How would that help? One sector is still pointing at the
interference.......Wouldn't that sector still make the radio fail,
if the -36 signal is what is doing it?
My question from the original post. Will that strong signal
desensitize the radio into failure? If not, then I need to figure
out what kills my radios. Why do they work fine for a month and
then die? I replace just the radio and they are fine for a while.
Brian
Marlon K. Schafer (509) 982-2181 wrote:
If you are that close to a source of interference you need to
ditch the omnis and sectorize our tower.
laters,
Marlon
(509) 982-2181 Equipment sales
(408) 907-6910 (Vonage) Consulting services
42846865 (icq) And I run my own
wisp!
[EMAIL PROTECTED]
www.odessaoffice.com/wireless
www.odessaoffice.com/marlon/cam
----- Original Message ----- From: "Brian Rohrbacher"
<[EMAIL PROTECTED]>
To: "Conversations over a new WISP Trade Organization"
<[email protected]>
Sent: Tuesday, February 20, 2007 7:05 AM
Subject: [WISPA] failing Canopy 900
I keep losing canopy 900 APs. I used the spectrum analyzer
yesterday and saw -36 signal on channels 928, 929, and 930. Will
that strong signal desensitize the radio into failure? because
for some reason SMs that used to be -65 are -80 (on both sides of
the like) and 17 out of 33 associations have dropped off the AP.
I've been fighting this for a year. I've installed my own
grounding, a lighting dissipater, 6 new APs, 2 new omnis, and 3
new cables. I think I have ruled out anything that could be
killing this AP except if something RF is killing it. Any input
will help.
Brian
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Jack Unger ([EMAIL PROTECTED]) - President, Ask-Wi.Com, Inc.
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