[linux-dvb] Re: Tuning problems with TT DVB-C 1500 (saa7146 +stv0297) and QAM128

Toni Lindroos tonilind.ml at nic.fi
Sun Aug 21 20:23:10 CEST 2005


Hi,

what kind of signal and s/n ratio values should I get with czap/femon? 
README says that over 0x8000 is OK for both but my values are considerably 
lower. Here's an example:

--- clip --- clip --- clip ---
tonilind at wnfmediast:/work/linuxtv-dvb-apps-1.1.0/util/szap> ./czap -c 
channels.conf "YLE TV1"
using '/dev/dvb/adapter0/frontend0' and '/dev/dvb/adapter0/demux0'
 19 YLE TV1:162000000:INVERSION_AUTO:6900000:FEC_NONE:QAM_128:512:650:17
 19 YLE TV1: f 162000000, s 6900000, i 2, fec 0, qam 4, v 0x200, a 0x28a
status 00 | signal 031e | snr 0612 | ber 00000000 | unc 00000000 |
status 00 | signal 031e | snr 0645 | ber 00000000 | unc 00000000 |
status 00 | signal 031d | snr 075f | ber 00000000 | unc 00000000 |
status 1f | signal 031c | snr 0faa | ber 00000000 | unc 00000000 | 
FE_HAS_LOCK
status 1f | signal 031c | snr 0e6b | ber 00000000 | unc 00000000 | 
FE_HAS_LOCK
status 1f | signal 031c | snr 0fb3 | ber 00000000 | unc 00000000 | 
FE_HAS_LOCK
status 1f | signal 031c | snr 1395 | ber 00000000 | unc 00000000 | 
FE_HAS_LOCK
status 1f | signal 031c | snr 0d4e | ber 00000000 | unc 00000000 | 
FE_HAS_LOCK
status 1f | signal 031c | snr 1259 | ber 00000000 | unc 00000000 | 
FE_HAS_LOCK
status 1f | signal 031b | snr 135b | ber 00000000 | unc 00000000 | 
FE_HAS_LOCK
status 1f | signal 031c | snr 0e02 | ber 00000000 | unc 00000000 | 
FE_HAS_LOCK
status 1f | signal 031b | snr 0e46 | ber 00000000 | unc 00000000 | 
FE_HAS_LOCK
status 1f | signal 031c | snr 0eda | ber 00000000 | unc 00000000 | 
FE_HAS_LOCK
status 1f | signal 031c | snr 106d | ber 00000000 | unc 00000000 | 
FE_HAS_LOCK
status 1f | signal 031b | snr 10c8 | ber 00000000 | unc 00000000 | 
FE_HAS_LOCK
status 1f | signal 031c | snr 0e48 | ber 00000000 | unc 00000000 | 
FE_HAS_LOCK
--- clip --- clip --- clip ---

I already tried two other cables but there were no changes in those values. 
If I remember correctly, TT's Windows software gave me full signal meter bar 
and about 60-70 % full s/n ratio meter bar. I'll try to confirm this later 
(and get some numerical data). I'll also try to get an antenna amplifier for 
testing.

Are there some values in drivers I can try to tweak?

-- 
Toni Lindroos <tonilind.ml@*NOSPAM*nic.fi>
Turku, Finland 






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