On Tue, 2 Mar 2010, Brendon Hoch wrote:
All,
Our Noaaport signal strength & errors are both outside of normal
thresholds:
[ldm@noaaport0 bin]$ ./s75status
Status for device: 0
Firmware Ver 3, Rev. 4 RF Firmware Codes: 0x506
------------------------------------------------------------------------
Symbol Rate 6.349000 Msps Frequency 1192.900024
The viterbi Bit Error Rate is 1.8792e-01 Viterbi Rate 2
LNB Power On, Polarization = 1, Band = 1
Signal Strength: 29 Signal Lock: 0 Data Lock: 0 Uncorrectables: 61
I've tried restarting the Novra with no success. The signal light is
blinking intermittently, and the lock light is off. Usually, both these
lights are steady green.
With our recent noreaster, we experienced wind gusts near 55 mph near where
our dish is located, so it is very possible our dish may need to be repeaked.
Yeah, that definitely sounds like the wind got to your dish. Usually, the
survival threshold is 65 MPH, so it may not have been bolted down as
tightly as it should have been. Then again, if heavy snow piled on the
dish, all bets are off.
The last time we had this done in 2005, the technician we used really didn't
seem to have any special equipment, all he seemed to do was make small
adjustments while I continued to run the s75status program until our signal
strength improved.
Not sure whether to hire the same guy, hire the other guy
(in rural NH, our options are limited! ;) ), or try to do the adjustments
myself; the "official" website at
http://www.weather.gov/noaaport/html/sat_loc.shtml does not have much for
newbies on this.
Any advice is greatly appreciated.
Brendon,
What it would involve is doing this. First, loosening up the bolt a
bit that controls the azimuth (horizontal) adjustments, peaking the signal
in that plane by pushing the dish slightly left or right as you face the
dish (probably left, towards the west, if you will). You must go in very,
very small increments; 2 degrees separate AMC-2 from other adjacent
satellites. I helped a broadcast engineer adjust the College of DuPage's
dish, and let me tell you, the movements are pretty small. Then, once you
peak it in the horizontal, you tighten it up good, and do the same in the
vertical, unless you are getting a very strong signal after peaking it in
the horizontal.
You need a couple of people with some good arms out there who can loosen
that bolt, and then GENTLY, VERY GENTLY tweak the dish in moving it in the
direction you need to go. If the dish is way off, first find a satellite
signal from anywhere, lock it in the vertical, and then keep "hopping"
from satellite to satellite to get to AMC-2. A professional engineer has a
"bird dog" meter which tells him what satellite he is looking at, and can
peak the signal more easily that way. As for us at NIU, we had a spare
analog satellite receiver box which picks up PBS analog on the same bird.
We got that weak signal as good as we could, then plugged it into my Novra
box, and all was well.
Again, be careful, as it is pretty easy to mess things up. Start with the
horizontal azimuth first, and ssee if you get anything. Given the ambient
wind flow, push the dish slightly westward to start.
Gilbert
*******************************************************************************
Gilbert Sebenste ********
(My opinions only!) ******
Staff Meteorologist, Northern Illinois University ****
E-mail: sebenste@xxxxxxxxxxxxxxxxxxxxx ***
web: http://weather.admin.niu.edu **
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