one problem when you do this is that when you connect the vu to the motor , the vu will move the motor to where it thinks that thor is
so when trying this , one option is to leave the spiderbox connected and connect the vu to the spider loop out , then place the spider in standby , if the motor still moves then leave the spider on as well, on one of those affected channels, then check if the spider and vu can both see that one channel, rinse and repeat for any others , so the spider is tuning the dish in and the vu is a slave to the spider
another option is to turn off the motor in the vu and have it set to single satellite , thor 0.8w , so it thinks its on a fixed dish
and yes tuners can and do vary , plus there are 4 lnb states to consider as well
HIGH - V
LOW - V
HIGH - H
LOW - H
where V = Vertical and H = Horizontal
13v and 18v are the voltages for high and low
I suppose it may well be that the VU tuner isnt as good as the spider
