I have an HR20 700, HR20 100, HR21 100 and an HR22 100. They are all working OK. The signal readings on the HR 20s show 99C in the high 80s to mid 90s. The readings on the HR 21 and HR22 show 99C in the low 70s to low 80s. Changing receiver location and switching BBCs makes no difference. I am wondering what are the real signal strengths? The dish was aligned originally using the HR20 700 signal meters before 99C was operational. Anyone else show a big difference between the signal readings of the HR20 and HR21 DVRs? I am having a big FM Yagi installed soon and I am wondering if they should tweak the dish or leave well enough alone.