Scalar Ring ? again

[Long Hair]

First I have a DMX741, should I set the ring to the feed horn markings or to the chaparral chart.
The reason I ask is between the two there is about a half an inch difference. On my big dish I had it set to the dmx chart but when I was trying to pull in the ku signal it when up about 12% quality when I moved the ring closer to the end of the feed horn, which was about where the chaparral chart would have been. So Could this mean that my focal distance is off? I came up with the focal length @ 45in. Be for I got the dish home the lnb was set to 42.8 which would make the depth @ 21in. When I measured it, I came up with 20in depth. Is it more likely that I measured wrong,or the original installer was wrong. Hope this rambling makes sense to someone. Thanks Long Hair

 

[brentb636]

Makes sense to me to put that ring where the signal is best . Calculations are fine but results are what counts. I think you're already on that track.

 

[beavs2112]

i agree with brentb636. i also have a dmx 741 and used the chaparral chart and got great results. also maybe check (if possible) that the vertical and horizontal polarity probe wires inside the feedhorn your 741 are straight. mine were bent curved so when i straightened them my c and ku quality readings improved dramatically 10-20 percent. it probably isn't easy to do but in my case it was well worth it.

 

[Long Hair]

Thanks for the reply guys. I was thinking maybe the focal distance might be off,because I had to move the ring closer!