Splitter and voltage problems

[Fox-xxxx]

4 cards budget, 1 splitter 4 ports power pass, vlc, linux 2.6.21.1

1 card set voltage=13 result it works
2,3,4 set voltage=0 result does not work

if 1,2,3,4 cards set voltage=13 result all cards does not work
(vlc always retune
[00000243] dvb access debug: frontend has lost FEC
[00000243] dvb access debug: frontend has lost sync
[00000243] dvb access debug: frontend has lost lock
[00000243] dvb access debug: frontend has acquired stable FEC
[00000243] dvb access debug: frontend has acquired sync
[00000243] dvb access debug: frontend has acquired lock
[00000243] dvb access debug: - Bit error rate: 34816
[00000243] dvb access debug: - Signal strength: 44196
[00000243] dvb access debug: - SNR: 53934

1-3 seconds)
change differents splitters same result

1. looks like that tuner does not work if voltage=0 !

2. why does vlc lose signal every 1-3 sec, if all dvb cards use voltage ?

can anybody test it on other dvb cards ?

[Fox-xxxx]

test another cards tt s-1401

if 1,2,3,4 cards set voltage=13 result all card's don't work (vlc lose signal
every 1-3 seconds and says that can't tune)

change differents splitters same result

[Fox-xxxx]

test 3
i use 2 pc
1 card in 1 pc
3 cards on 2 pc

result same!

[Fox-xxxx]

test 4
i try twinhan ci, os windows

1 home tuner, 1 dvb twinhan ci card, 1 splitter 4 out

on home tuner set voltage, on card set voltage=0

dvb-card does not work !