Some more tests:
dvbtune:
~ $ dvbtune -qam 64 -cr 2_3 -tm 8 -bw 8 -m -f 498000000
Using DVB card "Conexant CX22702 DVB-T"
tuning DVB-T (in United Kingdom) to 498000000 Hz
polling....
Getting frontend event
FE_STATUS:
polling....
Getting frontend event
FE_STATUS: FE_HAS_SIGNAL FE_HAS_LOCK FE_HAS_CARRIER FE_HAS_VITERBI FE_HAS_SYNC
Event: Frequency: 508600000
SymbolRate: 0
FEC_inner: 2
Bit error rate: 0
Signal strength: 30961
SNR: 65535
FE_STATUS: FE_HAS_SIGNAL FE_HAS_LOCK FE_HAS_CARRIER FE_HAS_VITERBI FE_HAS_SYNC
Signal=30961, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=30961, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=30961, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=30961, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=30961, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=30961, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=30961, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=30961, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=30961, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=30961, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=30961, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=30961, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=30961, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=30961, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=30961, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
etc...
dvbsnoop
# dvbsnoop -s signal
dvbsnoop V1.4.50 -- http://dvbsnoop.sourceforge.net/
---------------------------------------------------------
Transponder/Frequency signal strength statistics...
---------------------------------------------------------
cycle: 1 d_time: 0.001 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 2 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 3 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 4 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 5 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 6 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 7 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 8 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 9 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 10 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 11 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 12 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 13 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 14 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 15 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 16 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 17 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 18 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 19 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 20 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 21 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 22 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 23 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 24 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 25 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 26 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 27 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 28 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 29 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 30 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 31 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 32 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 33 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 34 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 35 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 36 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 37 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 38 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 39 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 40 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 41 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 42 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 43 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 44 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 45 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 46 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 47 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 48 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 49 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 50 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 51 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 52 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 53 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 54 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 55 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 56 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 57 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 58 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 59 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 60 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 61 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 62 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 63 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 64 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 65 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 66 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 67 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 68 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 69 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 70 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 71 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 72 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 73 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 74 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 75 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 76 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 77 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 78 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 79 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 80 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 81 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 82 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 83 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 84 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 85 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 86 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 87 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 88 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 89 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 90 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 91 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 92 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 93 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 94 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 95 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 96 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 97 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 98 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 99 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 100 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 101 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 102 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 103 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 104 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 105 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 106 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 107 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 108 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 109 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 110 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 111 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 112 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 113 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 114 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 115 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 116 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 117 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 118 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 119 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 120 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 121 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 122 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 123 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 124 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 125 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 126 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 127 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 128 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 129 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 130 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 131 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 132 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 133 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 134 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 135 d_time: 0.006 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 136 d_time: 0.008 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 137 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
cycle: 138 d_time: 0.007 s Sig: 0 SNR: 32768 BER: 16383 UBLK: 0 Stat: 0x00 []
etc...