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Guest Message by DevFuse

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Is a little jiggle alright?


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18 replies to this topic

#1 OFFLINE   wiz561

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Posted 01 February 2012 - 08:33 PM

Hi!

I had a d* SWiM dish installed last year on a pole mount. The installer used concrete and that part seems pretty solid. However, when a good gust of wind blows, the dish jiggles a little from the wind.

I was wondering if anybody can say how much is too much, where it would affect signal quality. The pole is pretty sturdy, and it's just the dish that jiggles around in the wind at times. I added an arm from the house to the pole, but it's not really doing much.

The reason I'm asking is because I'll occasionally get an audio drop out. I have the d* receiver connected to an Onkyo audio receiver, and will occasionally get an interrupted audio stream for a sec. No pixelation, just the audio. My signals are between 95 to 100 on a clear day. I was thinking that the audio drop outs might be from the dish swaying in the wind, but wanted to get some opinions here.

Thanks!

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#2 OFFLINE   Davenlr

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Posted 01 February 2012 - 08:42 PM

Assuming the bolts holding the reflector (dish) to the mount are tight, I wouldnt worry about it. As for audio drop outs, that is a Directv across the board problem from time to time. As long as the picture isnt pixellating, I doubt you have any problems.

There are also two bolts for elevation lock down, and two for azimuth lock down. Occasionally, after adjusting the dish, a tech will forget to lock those down. That could cause a little jitter too. Basically, just check all the nuts on the dish, make sure they are tight, without bumping the dish.

Tivo Premier XL4, Tivo Premier, Tivo HD whole home on Xfinity HD, DirecTv Whole Home with 39" high gain KaKu dish, Roku3,SageTv 8 TB Win8 Server -> DVDO Edge-> Denon AVR, Klipsch KB15's/Panasonic 55ST60 plasma"


#3 OFFLINE   veryoldschool

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Posted 01 February 2012 - 08:43 PM

Not sure about the dish, but the audio dropout I doubt is related, or everyone's dish is wiggling, at the same time.
A.K.A VOS

#4 OFFLINE   Davenlr

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Posted 01 February 2012 - 08:44 PM

Not sure about the dish, but the audio dropout I doubt is related, or everyone's dish is wiggling, at the same time.


:) That was a good one VOS.

Tivo Premier XL4, Tivo Premier, Tivo HD whole home on Xfinity HD, DirecTv Whole Home with 39" high gain KaKu dish, Roku3,SageTv 8 TB Win8 Server -> DVDO Edge-> Denon AVR, Klipsch KB15's/Panasonic 55ST60 plasma"


#5 OFFLINE   wiz561

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Posted 01 February 2012 - 08:49 PM

Thanks for the information. I checked all the bolts earlier today, and everything was tight.

So, I'm just being nosey....but how much do you have to nudge the dish in order for it to degrade a signal? Quarter inch? 1 inch?

I never aimed a dish myself, but I'm just imagining that the smallest little nudge will break the signal.

Thanks again for the information.

#6 OFFLINE   Davenlr

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Posted 01 February 2012 - 08:56 PM

About 2 millimeters will degrade the HD signal. The turns per inch of the adjusting bolts on the mount. One full turn can dramatically degrade your HD signal. 95-100's on the signal quality screen indicates the dish is well aligned.

If you moved the dish 1 inch horizontally, you would probably pass the satellite next to the one you want, and pick up the second one. They are located 2 degrees apart in the sky. 2 degrees isnt much.

Tivo Premier XL4, Tivo Premier, Tivo HD whole home on Xfinity HD, DirecTv Whole Home with 39" high gain KaKu dish, Roku3,SageTv 8 TB Win8 Server -> DVDO Edge-> Denon AVR, Klipsch KB15's/Panasonic 55ST60 plasma"


#7 OFFLINE   veryoldschool

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Posted 01 February 2012 - 08:57 PM

Thanks for the information. I checked all the bolts earlier today, and everything was tight.

So, I'm just being nosey....but how much do you have to nudge the dish in order for it to degrade a signal? Quarter inch? 1 inch?

I never aimed a dish myself, but I'm just imagining that the smallest little nudge will break the signal.

Thanks again for the information.

There is about a 2 degree window
A.K.A VOS

#8 OFFLINE   veryoldschool

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Posted 01 February 2012 - 09:00 PM

About 2 millimeters will degrade the HD signal. The turns per inch of the adjusting bolts on the mount. One full turn can dramatically degrade your HD signal. 95-100's on the signal quality screen indicates the dish is well aligned.

Not sure where you're measuring the 2 millimeters, but dithering my dish, takes a good 7 full turns from one edge to the other edge, leaving the center 3.5 turns, so 1 full turn isn't that "dramatic".
A.K.A VOS

#9 OFFLINE   Davenlr

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Posted 01 February 2012 - 09:02 PM

Not sure where you're measuring the 2 millimeters, but dithering my dish, takes a good 7 full turns from one edge to the other edge, leaving the center 3.5 turns, so 1 full turn isn't that "dramatic".


Yea, forgot, mine is tighter (its a 1 meter dish). That 7 full turns from edge to edge on KA or KU? i.e. are you using Directvs dither method, or dithering KA? Just curious. I was measuring it on the bolt.

Tivo Premier XL4, Tivo Premier, Tivo HD whole home on Xfinity HD, DirecTv Whole Home with 39" high gain KaKu dish, Roku3,SageTv 8 TB Win8 Server -> DVDO Edge-> Denon AVR, Klipsch KB15's/Panasonic 55ST60 plasma"


#10 OFFLINE   wiz561

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Posted 01 February 2012 - 09:05 PM

Wow! :eek2: 2mm! 2 degrees! No wonder people say don't mess with the alignment unless you have the right tools.

#11 OFFLINE   veryoldschool

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Posted 01 February 2012 - 09:05 PM

Yea, forgot, mine is tighter (its a 1 meter dish). That 7 full turns from edge to edge on KA or KU? i.e. are you using Directvs dither method, or dithering KA? Just curious. I was measuring it on the bolt.

I kind of guessed you weren't at the reflector. :lol:
Standard Slimline with SWiM, where the "edge" is "80ish" on a Ka TP.
A.K.A VOS

#12 OFFLINE   wiz561

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Posted 01 February 2012 - 10:19 PM

I was thinking about this more, and I suppose that there are a number of different axis' that can be wiggled. I was talking more of a back and forth (left to right, if looking at the dish) motion, and not a twistie motion....if that makes any sense!

In any case, it's been a good read, and thanks for the info.

#13 OFFLINE   veryoldschool

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Posted 01 February 2012 - 10:47 PM

I was thinking about this more, and I suppose that there are a number of different axis' that can be wiggled. I was talking more of a back and forth (left to right, if looking at the dish) motion, and not a twistie motion....if that makes any sense!

In any case, it's been a good read, and thanks for the info.

There are two axis [AZ & EL], but the is also a fixed tilt.
A.K.A VOS

#14 OFFLINE   HoTat2

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Posted 02 February 2012 - 10:56 AM

Not sure where you're measuring the 2 millimeters, but dithering my dish, takes a good 7 full turns from one edge to the other edge, leaving the center 3.5 turns, so 1 full turn isn't that "dramatic".


The seven full turns between beam edges applies to broad nose Ku beam (at 101) where granted something like 1 turn of the dish's veneer Az/El adjustments wouldn't amount to much.

But shouldn't even a single full turn of the veneer adjustments one way or the other have a substantial effect on the Ka-band transponder strengths given their much narrower beam-widths?

#15 OFFLINE   veryoldschool

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Posted 02 February 2012 - 11:15 AM

The seven full turns between beam edges applies to broad nose Ku beam (at 101) where granted something like 1 turn of the dish's veneer Az/El adjustments wouldn't amount to much.

But shouldn't even a single full turn of the veneer adjustments one way or the other have a substantial effect on the Ka-band transponder strengths given their much narrower beam-widths?

Guess you posted this before reading my follow on post, because "7 full turns" was with a Ka SAT & TP.
This was with a SWiMLNB, so it might be less without one.
A.K.A VOS

#16 OFFLINE   HoTat2

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Posted 02 February 2012 - 11:33 AM

Guess you posted this before reading my follow on post, because "7 full turns" was with a Ka SAT & TP.
This was with a SWiMLNB, so it might be less without one.


No I read your follow on post a number of times, but did not really understand it.

I didn't think it was possible (or maybe "practical" is a better term?) to dither on the very narrow Ka-band beam peaks.

Dithering is done to locate the center of the much broader, and thereby easier to measure, 101 Ku-band beam peak. Then through logical inference the Ka-band beam peaks are assumed centered as well.

#17 OFFLINE   veryoldschool

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Posted 02 February 2012 - 11:43 AM

No I read your follow on post a number of times, but did not really understand it.

I didn't think it was possible (or maybe "practical" is a better term?) to dither on the very narrow Ka-band beam peaks.

Dithering is done to locate the center of the much broader, and thereby easier to measure, 101 Ku-band beam peak. Then through logical inference the Ka-band beam peaks are assumed centered as well.

:confused: Dithering is the same.
What you may be mistaking is how some techs align a dish and end up with it having low Ka numbers.
The old training video showed dithering off the Ku, as the meters then couldn't read Ka.
Dithering is still dithering though.
I do a course alignment off the 101, and then move to the Ka for the fine tuning, since "nailing" Ka also nails the Ku, and is more accurate being the narrower beam.
A.K.A VOS

#18 OFFLINE   HoTat2

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Posted 02 February 2012 - 12:32 PM

:confused: Dithering is the same.
What you may be mistaking is how some techs align a dish and end up with it having low Ka numbers.
The old training video showed dithering off the Ku, as the meters then couldn't read Ka. ...


Wow, guess I'm way behind the times on the capabilities on today's alignment meters (or most of them anyhow). :lol:

Yes, I still thought the Ka beam peaks were neither visible to the meters nor practical to try and dither off them even if they were due to their steep edges causing very rapid rise and fall times either side of their peaks.

#19 OFFLINE   veryoldschool

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Posted 02 February 2012 - 02:13 PM

Wow, guess I'm way behind the times on the capabilities on today's alignment meters (or most of them anyhow). :lol:

Yes, I still thought the Ka beam peaks were neither visible to the meters nor practical to try and dither off them even if they were due to their steep edges causing very rapid rise and fall times either side of their peaks.

The fine adjustment screws make it fairly easy.
Without them, I don't think anyone would get very close.
A.K.A VOS




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