Is the cable on your home stapled down or are there clips that hold your cable to the home. Among the other suggestions here, I would tell you that you should inspect your cable very carefully. Is it crushed or crimped in anyway....did this "high quality installer" run through RG-59 cable? Finally if it is acting the same on all three receivers, I would suggest that you have a bad switch or a bad LNB.
This is CABL.com posting #177816. Tiny Link: cabl.co/mUqa