strange problem when using two boxes

[sb18180]

just wondering if anyone else come across this problem when i have two skyboxes f5 switched on i lose signal on one of the boxes from frequency 12000 onwards both vertical and horizontal. iam using a quad lnb so both boxes have their own feeds no splitting of cables any ideas anyone?
cheers.

[sb18180]

think i found out whats causing it iam only getting a signal of 67% on some channels dish must have moved. what is a good signal strength to have to stop drop outs?

[DW190]

think i found out whats causing it iam only getting a signal of 67% on some channels dish must have moved. what is a good signal strength to have to stop drop outs?

My strength is on 90% and quality varies between 70 & 75