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Discussion Starter #1
We have a bit of a problem

We were all set up with the motor working and all - satellites coming in etc

A couple of weeks ago - we noticed the 125W was not coming in regularly or digitizing when it did.

Now anything further west of 101W is not coming in at all - others below are OK

Short of chopping down the tree - (I know I am being naive here) - can anyone think of any solutions?
 

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Please describe the details of your satellite antenna system. Then maybe someone can offer some help.

For instance mine is:
A 7.5 foot, C/Ku mesh parabolic dish, made by Perfect 10, with a C/Ku Chapparel feedhorn, using a 24" Actuator arm, which is driven by an older Analog Receiver (to move it).
 

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Discussion Starter #3
Sorry - it used to be on my signature - but appears to have disappeared

We have a Kbox receiver with a 1m dish motorized, 2 Lnbs - one is linear and the other circular

We also have an antenna that we got off ebay about a year ago - it is motorized as well.
 

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OK, if you suspect some trees are getting in your way, you can try and use
this tool to try and find a new location on your property which might clear the
trees better.

http://www.dishpointer.com/

If that were the case I'd expect that during the winter you had no problems,
and gradually from spring onwards ya started losing 'em.
How long have ya had your system running?
Is it old enough to have been through several seasonal changes without issue in the past, or is this a completely new issue?
You wanna be able to rule out an obstruction issue vs not tracking the arc properly as an issue.
An obstruction issue can only be fixed by physically moving the installation or removing the obstruction,
while a lack of tracking issue can likely be fixed with proper alignment...unfortunately I don't use the
small dishes with diseqc motors, so I won't be of much help there.
But perhaps someone else can help ya though.
 

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Try pointing the dish manually by hand to 125w and see if you will get a good signal. Possibly the wind has moved the dish on the motor arm, and motor needs to be re-calibrated.
 

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Discussion Starter #6
Thanks to all for your suggestions. We are trying a blind scan again - and yes - we had this system put up in the late spring - so darn those trees that grow.

However, they are not deciduous - one is a eucalyptus and the other some sort of fir - don't expect things will change for the better in the fall.:confused:
 

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LadyBear, did you try out the dishpointer link above?
Is the amount space on your property limited?
Is the dish mounted on a pole on the ground, or is it a rooftop install?

If it were the trees obstructing, I'd expect it to only be a problem on the specific satellites being blocked/partially blocked. The rest in the arc that aren't obstructed should be fine.

How bad is it? Do you know which satellite positions you're able to see, and which ones you can't?
possible solution:
measure the horizontal distance from the tree causing the issue, to your antenna.
Ideally Measure if you can the height of the tree, best estimate of height if not.

You now have two sides of a right triangle, you can now calculate the minimum angle that ur dish needs to clear,
Given the dish position on the ground, and the height of the tree..

Min elev. Angle = Inv Tan (Opposite/Adjacent)
where:
Opposite is the tree height
Adjacent is the Distance between ur dish and the tree.

U can do this in Windows Calculator,
Start, Programs, Accessories, Calculator. Then View Scientific Mode,
once in calculator. You'll now see the Trig Functions.

http://www.mathwarehouse.com/geometry/triangles/right-triangle.html

http://www.mathwarehouse.com/trigonometry/sine-cosine-tangent.html

Example:

Tree Height 50 ft, dish mounted on a pipe 6 ft high near the ground.
Distance from tree to dish is 75 ft

Opposite = Tree height - dish height, or 50 -6 = 44 ft
Adjacent = 75 ft

Min Elevation Angle = Inv Tan(44/75) = Inv Tan (.59)
Min Elevation Angle = 30.4 degrees.

Now ya take that 30.4 degrees and compare that to what the elevation angle
of the satellite(s) being blocked should be if it's aimed properly, using your coordinates. You wanna clear it by
more than a few degrees. Every Satellite in the direction of the tree, requiring an elevation
lower than that 30.4 degrees would be blocked.

Move the dish 25 ft further away from the tree to 100 ft from the tree.
crunching the numbers again, U can now see down to 23.7 degrees.
repeat as is practical vs what ya can live with, etc.
 

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Discussion Starter #8
Hi Majortom

Unfortunately, we are on a city lot. We had someone install the dish because we could not get a signal when we were trying to put the motor up. We spent MANY hours trying to find the best spot - and by process of elimination, along with the installer - came up with the present spot. It is on a pole - on our roof.
It appears to be only sat AMC 21 (of course that was the one that sold us on the system) - and tonight when we did a blind scan - it does not come in at all. We found the others are coming in even better right now and apparently 97 just added some more stations.
 

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that figures...
Regardless, if ya plug the numbers in, and do the math, and you
find you shouldn't even be close to having an obstruction issue,
then ya just ruled out something.

Here are some known signals on AMC 21.
Is your receiver capable of DVB-S2?
I guess you're trying for the PBS located there?


Code:
961 LPBS SD AMC 21 125°W 12072 H 16666 3/5  Off ITC DVB-S2 8PSK Jun 17, 2010 
962 LPBS SD AMC 21 125°W 12072 H 16666 3/5  Off ITC DVB-S2 8PSK Jun 17, 2010 
963 LPBS SD AMC 21 125°W 12072 H 16666 3/5  Off ITC DVB-S2 8PSK Jun 17, 2010 
964 LPBS HD AMC 21 125°W 12072 H 16666 3/5  Off ITC DVB-S2 8PSK Jun 17, 2010 
965 PBS Montana AMC 21 125°W 12103 V 4340     ITC   Jun 17, 2010 
966 OETA SD AMC 21 125°W 12112 V 8705 3/4  Off ITC DVB-S2 8PSK Jun 17, 2010 
967 OETA HD AMC 21 125°W 12112 V 8705 3/4  Off ITC DVB-S2 8PSK Jun 17, 2010 
968 PBS HD East AMC 21 125°W 12140 V 30000 3/4    ITC   Jun 17, 2010 
969 PBS HD West AMC 21 125°W 12140 V 30000  3/4    ITC   Jun 17, 2010 
970 PBS HD Feeds AMC 21 125°W 12150 H 14030     ITC   Jun 17, 2010 
971 BBC Occasional Feeds AMC 21 125°W 12170 H 4444     ITC   Jun 17, 2010 
972 PBS SD Feed AMC 21 125°W 12180 V 30000  3/4    ITC   Jun 17, 2010 
973 PBS Create AMC 21 125°W 12180 V 30000  3/4    ITC   Jun 17, 2010 
974 PBS HD Feed AMC 21 125°W 12180 V 30000  3/4    ITC   Jun 17, 2010 
975 PBS SD Feed AMC 21 125°W 12180 V 30000  3/4    ITC   Jun 17, 2010 
976 PBS World AMC 21 125°W 12180 V 30000  3/4    ITC
 

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I'm experiencing severe signal quality fluctuations with certain transponders on AMC 21. Some PBS signals that were viewable 30 minutes ago, with good signal quality (just a touch under 50) are now unwatchable. The only ones I can get reliably right now are the transponders carrying Montana PBS, a few feeds showing test patterns, and a channel testing MPEG4 encoding.
As I'm typing this, PBS World is fading in and out, with the signal monitor showing zero, sometimes peaking in the upper single digits.
Perhaps this is adding to your reception difficulties?
 

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AMC 21 125°W Reception Problems.

I am also wondering if there are problems with this satellite. My location is Port Moody, BC, on the 17th floor of an apartment building. My longitude is 122.8°W. I have a 36" motorised dish which gets many satellites OK, although I could do with replacing the balcony glass with Plexiglas to improve reception on some.

Reception of AMC 21 125°W is marginal because the concrete balcony above obstructs a clear view of this satellite and short of taking a pneumatic drill to take out a piece of the balcony, this isn't going to improve. ;)

Signals I can get are transponder 12180 MHz (PBS World etc), some of the HD and SD feeds and Montana PBS which is watchable some days and not even detectable others. No sign of PBS HD East and West and no chance of DVB-S2 channels

I had a 24" dish I decided to erect where it had a clear view of the satellite. Reception was about or slightly better than motorised dish. So, I went and bought a 30" dish which should give another 2dB of signal over the 24" dish which I hoped would improve things. The quality is improved on some transponders, but I would think 2dB signal increase should show quite an improvement. Still no sign of Montana PBS or the PBS HD East and West. I can't put up a larger dish than 30".

On 30th September, I also notice that PBS World and other channels were fading badly, but came back after a while. Maybe the satellite needs repositioning on station again, or possibly starting to fail with some transponders putting out lower power levels. The field strength in my area is supposedly >46 dBW according to the SES website, but I question this due to my reception findings. It will be interesting to find out what is going on.
 

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hmm, 2 of u in BC, 1 in Calgary? I'm in NY, near Buffalo
I just tested each transponder and exported some HTML for each one from TsReader. Below is a link, u can extract to a temp directory and open html. At the bottom of each transponder's HTML you'll see the signal/quality reported. Saw some errors evident on Louisiana PBS that I'm not used to
seeing. I'm using a 7.5 ft C/Ku dish and a Prof 7500 USB DVB-S2 Tuner.
The DVB-S2 signals will always be the toughest to receive
especially if a satellite is having problems.
I'll ask around in a few other areas too. See what the story is.

https://docs.google.com/leaf?id=0B1...NzEwZjA2YzkwNzk4&sort=name&layout=list&num=50
 

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Just tried the link and got an error message …
"Sorry, the page (or document) you have requested is not available.
"Please check the address and try again."
 

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AMC 21 125°W Reception Problems.

So, it looks like there are some problems. One possible answer is that AMC 21 has a wobble and the beam direction is moving around slightly.

Echostar 5 129°W (now replaced with Ciel 2) had a wobble and in the Pacific Northwest, the quality level would fall until the satellite was not received for up to two hours. Then the quality level would steadily improve and be fine for a few days.
 
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