Dish arc, true south or magnetic? - Techwatch Support Forums: Digital & Satellite TV, FTA, Cable, Computers, Mobile Phones, Apple and General Tech Forums

seanile · 05-10-09, 01:46 PM

Novice question
I have a question about seting up a motorized system, and am somewhat confused which longitude I should use for the perfect arc setup.
My location is LAT 51.6, Long -1.8464(W), so should I use true south at 180.0 or should I use Magnetic at 182.5, because when selecting the satellite at 1deg west the dish would have to move east fractionaly if using true south 178.9 or would be virtualy at 181.4 magnetic south at 1 deg west?
I have clear view for about 60 deg each side so would like to get best set up possible with your help.

TheBadger · 06-10-09, 07:39 AM

With the setting on the mount at 000 the dish is at the zenith of the arc and should be pointing true south only if your longitude is 000. From your longitude true south is as close to the satellite position 1W as makes little difference so use that to peak your dish.

05-10-09, 01:46 PM	#1 (permalink)
seanile Junior Member Join Date: Aug 2009 Posts: 2 Thanks: 0 Thanked 0 Times in 0 Posts	Dish arc, true south or magnetic? Novice question I have a question about seting up a motorized system, and am somewhat confused which longitude I should use for the perfect arc setup. My location is LAT 51.6, Long -1.8464(W), so should I use true south at 180.0 or should I use Magnetic at 182.5, because when selecting the satellite at 1deg west the dish would have to move east fractionaly if using true south 178.9 or would be virtualy at 181.4 magnetic south at 1 deg west? I have clear view for about 60 deg each side so would like to get best set up possible with your help.

06-10-09, 07:39 AM	#2 (permalink)
TheBadger Senior Member Join Date: Mar 2006 Posts: 202 Thanks: 1 Thanked 10 Times in 10 Posts	Dish arc, true south or magnetic? With the setting on the mount at 000 the dish is at the zenith of the arc and should be pointing true south only if your longitude is 000. From your longitude true south is as close to the satellite position 1W as makes little difference so use that to peak your dish. __________________ I used to be paranoid but now I'm a victim!