Integrator's Manual

124
Appendix B
RF Sanity Check
In order to address the situation where a receiver loses its authorization every 3 to 4 days, we
recommend that installers perform a spot check to verify that the COM1000 can successfully
tune to each of the satellite/transponder pairs where the DIRECTV program guide updates can be
found.
As a final check to confirm that correct RF signal levels are being received by the COM24 cards,
the following table summarizes “typical” SNR and AGC values that must be received to ensure
proper operation of the COM1000. It should be noted that this table is only valid for the
CONUS (Continental United States) feeds. The guide data for local channels is located
elsewhere on the 101 satellite.
Table 6 – RF Spot Check Values
DTV Channel
Sat network
Freq. Index
SNR
AGC
3
(dBm)
229
0 (101 sat)
26
≥10
-55 to -25
230
0 (101 sat)
31
≥10
-55 to -25
427
3 (119 sat)
30
≥10
-55 to -25
Note: These are all of the frequencies where DIRECTV Program Guide updates and CAPs are
received. Having signal problems here can cause channels to be missing from the program
guide, causing general system instability and resulting in authorizations being missed or
dropped after several days.
3
Although named AGC, this value is essentially the power level at the input of the COM24 card.