focal length?

[rover54]

hi all ive been messin with my dish all day grrrrr still getting odd channels on 1 sat even on the next my poleroter is turning so im thinkin my lnb is not ajusted right ive got a 8 ft dish with a pipe coming through the center focal lenth now is 34 inches is that where its sposed to be ? also where should the lnb be pointing on the dish thanks in advance this thing is trying my nerves im about ready to hook chain to it and thow it in scrap pile

 

[rover54]

forgot to say that dish is 8 ft wide and 14 deep

 

[determined]

The focal length is D squared divided by 16d.
D is the dish diameter in inches
d is the dish depth in inches
for you it would be 96x96 divided by 16 divided again by14, or, 41.14 inches.

Make sure the dimensions are measured accurately as an error can make a lot of difference.

41 1/8 inches is a long ways from what you are saying you have that is working, but it still sounds like a rotor servo problem. Can you go into your receiver with a menu and adjust the skew around to see if you can get the other channels or make the ones you get go away? Anytime that this has happened to me it was because my servo motor had failed. They hate lightning. Don't give up. Man is the master and the machine is the servant. Make it so.

 

[gizzer777]

Also...

The focal length is D squared divided by 16d.
D is the dish diameter in inches
d is the dish depth in inches
for you it would be 96x96 divided by 16 divided again by14, or, 41.14 inches.
Make sure the dimensions are measured accurately as an error can make a lot of difference.
41 1/8 inches is a long ways from what you are saying you have that is working, but it still sounds like a rotor servo problem. Can you go into your receiver with a menu and adjust the skew around to see if you can get the other channels or make the ones you get go away? Anytime that this has happened to me it was because my servo motor had failed. They hate lightning. Don't give up. Man is the master and the machine is the servant. Make it so.

Even though the focal distance is computable...once you get it to the 41.14 inches, then move it in and out by a hair at a time for best quality readings!

I agree, it still sounds like a servo issue (or polarotor) If you hear the servo motor going when you hit the channel button, next step is to make sure the probe is moving!!! If not...you found the issue!

 

[pebo666]

Mine did the same thing. I checked the servo and probe and it was turning. Mine was solved by turning the LNB to the 4:30 position. I now recieve H & V.

 

[rover54]

thanks for replys to get mesurements i just messured across the dish to get the 8 ft and for dept i clamped a piece of light angle iron across the front and mesured from scaler ring to center of dish to get the 34 inchs anyway i checked continuity of wires going to dish they all checked out ok i clipped all wires and cleaned them up the poleroter does move when u change channels lnb is held on with a muffler clamp type deal ive turned it a few times anyway i unplugged reciver and turned it back on and can now get both odd and even channels but nether very good skewing it doesnt seem to change it all that much but when u fine or change the vidio fine numbers that on the other hand will make picture get worse or better but still not good ill try ajusting the lnb to the 41.14 inches and see if that helps move the lnb to the 4.30 posistion u mean like a clock? well thanks everyone

 

[rover54]

evning all today i moved lnb out to 41 inchs and lost picture toyed with it back and forth still no picture so i moved it back to where it was before moving it 34 inches and got picture back went to menards and got a little satellite finder and didnt even move the meter off 0 im stumped could the servo box been turned wrong when i put it back on ive fiddeled with it so much im not sure where it was when i started im getting both odd and even channels but like i said not good and skewing it dont change it all that much

 

[gizzer777]

Always mark

evning all today i moved lnb out to 41 inchs and lost picture toyed with it back and forth still no picture so i moved it back to where it was before moving it 34 inches and got picture back went to menards and got a little satellite finder and didnt even move the meter off 0 im stumped could the servo box been turned wrong when i put it back on ive fiddeled with it so much im not sure where it was when i started im getting both odd and even channels but like i said not good and skewing it dont change it all that much

It is a bit late now, but you always mark spots where the setup, worked....just in case.

It is starting to sound like an alignment problem with the dish or perhaps a flakey LNB (if alignment is good). What satellite CAN you get? Can you get the 1st on the east side and the last on the west side...as well as the middle of the ark?

 

[rover54]

hi well i marked spot on pipe before i moved focal lenth what i didnt was poler roter when i took it off wich direction the slot on it was but then it wasnt working where it was anyway not sure about end satellites i get the tv preacher on s3 channel 20 i think and have seen somthin close to the other end also in the middle i had sombody speaking spanish not sure where i was tho

 

[gizzer777]

Pretty important

hi well i marked spot on pipe before i moved focal lenth what i didnt was poler roter when i took it off wich direction the slot on it was but then it wasnt working where it was anyway not sure about end satellites i get the tv preacher on s3 channel 20 i think and have seen somthin close to the other end also in the middle i had sombody speaking spanish not sure where i was tho

it is probably a good idea to try for the further most east and western birds and get them stored (and identified) and tuned in...as well as a satellite in the middle of the belt. Then you can proceed to dial it in correctly. If anything is set wrong...it will show its head here while you are trying for the extremities (most likely as far as tracking goes)

As far as the preacher goes,....there are tons of them up there, and they all seem to have a great signal!!!!

 

[rover54]

thanks for reply ok ill try that in a cbit is there a good grid guide avalable somplase to view? the one i looked at really didnt seem to show free channels and or wild feeds and thats all i get so would help if i knew what was where thanks

 

[gizzer777]

Did you go to Lyngsat?

thanks for reply ok ill try that in a cbit is there a good grid guide avalable somplase to view? the one i looked at really didnt seem to show free channels and or wild feeds and thats all i get so would help if i knew what was where thanks

www.lyngsat.com for FTA...click on your country on the left, then choose a satellite on the right and double click....the channel "map" will be there.
look for the "F"'s

 

[rover54]

ok ill try that thanks

 

[jackpeas]

Skyvision has a guide in they catalog.

Hi I am jackpeas in Chicago.I get a catalog from skyvision.Its got the guide inside.I am having the same problems polarity.I had this problem back in march 17 2005.I for got what i did to correct it.See I have total of 5 inside the house now.With a pansat 2c 2ku on the dish and another ADL 2c 2ku in the garrage.I found that I had 2 bad feed.1 coroto and 1 adl had a broken shaft inside.1 made that buzzz sound but it was bad.Don't go by the sound.Look inside to it move.Are you wondering why he got so many feeds?yes you are.Here we go, like I am having the polarity problem.I would replace the feed,cables, and change the lnb.If something go wrong with my arm.Get a new arm.So I have more arms, feeds,cables..Thank

 

[rover54]

wow went to lyngsat and nothin there made any sence to me im not fermiler with any of those sats or birds what the hell happened vto gi f3 g5 s3 or w3 so on and so forth im looking at the last onsat i bought wich was dec 2000 isuue has so much changed in 6 years i asuming everything i saw on lyngsat was digital so i wont get it anyway ??? i went to onsat online and looked at satellite chart and they didnt show much for free anymore i got some other progects i better get busy on i guess ill read some of the old posts here whewn i get time and try to edjucate myself cause what i see u guys talking about here isnt fermiliar at all to me eitherv hdtv and the recivers your talking about side cars so opn and so forth thanks for all the advise

 

[charper1]

Analog C/Ku Chart: http://skyvision.com/pages/information_center/satarc1.htm

4DTV C/Ku Guide: http://skyvision.com/pages/information_center/4dtvguide.html

MPEG / FTA Chart: http://skyvision.com/pages/information_center/fta_mpeg2_no_am_east.html

 

[rover54]

ahhh thank u these birds r fermiliar ill get my limits set and see if i can get a couple stored and get back to my problum

 

[WyrTwister]

wow went to lyngsat and nothin there made any sence to me im not fermiler with any of those sats or birds what the hell happened vto gi f3 g5 s3 or w3 so on and so forth im looking at the last onsat i bought wich was dec 2000 isuue has so much changed in 6 years i asuming everything i saw on lyngsat was digital so i wont get it anyway ??? i went to onsat online and looked at satellite chart and they didnt show much for free anymore i got some other progects i better get busy on i guess ill read some of the old posts here whewn i get time and try to edjucate myself cause what i see u guys talking about here isnt fermiliar at all to me eitherv hdtv and the recivers your talking about side cars so opn and so forth thanks for all the advise

This is a sat chart showing analog C band . Color coded for the free and the VC2 encripted channels , using the sat names you may be familiar with . Somw of us newer guys are not familiar with the names you use ( I use the names from lyngsat.com ) . The chart also has those new names and 4DTV names .

Wyr

 

[drhydro]

For those confused by the different naming conventions: The sat chart offered by nps at callnps.com uses the old sat names along with the sats position. Then look at the sat postion on lyngsat and you can match up old names with new names using the sat postions. Kind of clumsy but it works ;-)

 

[Shawn95GT]

I like this chart:

http://www.4dtvforum.com/sat_chart.php

4DTV name, real name, and orbital position all in one. It's also printable so you can pencil in your position numbers too.

It was confusing to translate 'old sats names' to 4DTV names as some have moved.