The signal is sampled every 1.5 minutes so short signal losses will be missed underestimating the total number of times the signal has been lost. The total time the signal has been lost should average out close to the correct value. Signal loss is when the graphs go to zero. I am not sure at what signal strength the picture becomes unwatchable. It is possible a small percentage of the signal dropouts are due to monitoring errors. I am located in Bethesda Maryland
In the graphs blank spots may either be my receiver box (D10-200) locking up or problems with my PC. In January 2006 Directv upgraded the firmware on the box and it has not locked up since then but require a phone call to get reauthorized. They downloaded a new version 0x1004 after that problem. It has been working fine with my mythtv but using the boxes automatic channel change for use with VCR occasionally fails so static is recorded.
Back to by directv page or my pdp-8 page
Modified sensord by Merlin Hughes, all credit to the lm_sensors crew.