Więc tak:

_
Na uruchomionym VisualGPS:
COM2/57600 - rusza odbiornik, log zapisuje (niżej)
COM4/4800 - nie uruchamia sie odbiornik przez dłuższy czas (niebieski LED nie błyska), ale po kilkunastu sekundach rusza. Log jest pusty.
COM4/57600 - uruchamia się od razu i zapisuje log:
$GPGGA,000001.033,,,,,0,00,,,M,0.0,M,,0000*57
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,3,1,12,20,00,000,,10,00,000,,31,00,000,,27,00,000,*7C
$GPGSV,3,2,12,19,00,000,,07,00,000,,04,00,000,,24,00,000,*76
$GPGSV,3,3,12,16,00,000,,28,00,000,,26,00,000,,29,00,000,*78
$GPRMC,000001.033,V,,,,,,,291006,,,N*40
$GPGGA,000002.030,,,,,0,00,,,M,0.0,M,,0000*57
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000002.030,V,,,,,,,291006,,,N*40
$GPGGA,000003.034,,,,,0,00,,,M,0.0,M,,0000*52
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000003.034,V,,,,,,,291006,,,N*45
$GPGGA,000004.035,,,,,0,00,,,M,0.0,M,,0000*54
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000004.035,V,,,,,,,291006,,,N*43
$GPGGA,000005.033,,,,,0,00,,,M,0.0,M,,0000*53
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000005.033,V,,,,,,,291006,,,N*44
$GPGGA,000006.037,,,,,0,00,,,M,0.0,M,,0000*54
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,3,1,12,20,00,000,,10,00,000,,31,00,000,,27,00,000,*7C
$GPGSV,3,2,12,19,00,000,,07,00,000,,04,00,000,,24,00,000,*76
$GPGSV,3,3,12,16,00,000,,28,00,000,,26,00,000,,29,00,000,*78
$GPRMC,000006.037,V,,,,,,,291006,,,N*43
$GPGGA,000007.030,,,,,0,00,,,M,0.0,M,,0000*52
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000007.030,V,,,,,,,291006,,,N*45
$GPGGA,000008.032,,,,,0,00,,,M,0.0,M,,0000*5F
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000008.032,V,,,,,,,291006,,,N*48
$GPGGA,000009.034,,,,,0,00,,,M,0.0,M,,0000*58
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000009.034,V,,,,,,,291006,,,N*4F
$GPGGA,000010.030,,,,,0,00,,,M,0.0,M,,0000*54
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000010.030,V,,,,,,,291006,,,N*43
$GPGGA,000011.035,,,,,0,00,,,M,0.0,M,,0000*50
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,3,1,12,20,00,000,,10,00,000,,31,00,000,,27,00,000,*7C
$GPGSV,3,2,12,19,00,000,,07,00,000,,04,00,000,,24,00,000,*76
$GPGSV,3,3,12,16,00,000,,28,00,000,,26,00,000,,29,00,000,*78
$GPRMC,000011.035,V,,,,,,,291006,,,N*47
$GPGGA,000012.037,,,,,0,00,,,M,0.0,M,,0000*51
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000012.037,V,,,,,,,291006,,,N*46
$GPGGA,000013.033,,,,,0,00,,,M,0.0,M,,0000*54
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000013.033,V,,,,,,,291006,,,N*43
$GPGGA,000014.034,,,,,0,00,,,M,0.0,M,,0000*54
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000014.034,V,,,,,,,291006,,,N*43
$GPGGA,000015.037,,,,,0,00,,,M,0.0,M,,0000*56
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000015.037,V,,,,,,,291006,,,N*41
$GPGGA,000016.034,,,,,0,00,,,M,0.0,M,,0000*56
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,3,1,12,20,00,000,,10,00,000,,31,00,000,,27,00,000,*7C
$GPGSV,3,2,12,19,00,000,,07,00,000,,04,00,000,,24,00,000,*76
$GPGSV,3,3,12,16,00,000,,28,00,000,,26,00,000,,29,00,000,*78
$GPRMC,000016.034,V,,,,,,,291006,,,N*41
...
COM7(AGPS)/57600 - jak na COM4: rusza bez problemu, log taki sam.
Wychodzi na to, że na 57600 działa poprawnie, na 4800m nie.
A sygnału jak nie ma tak nie ma

-- EDIT --
Odpaliłem SirfTech. Log wygląda tak:
...
$GPGGA,000014.030,,,,,0,00,,,M,0.0,M,,0000*50
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000014.030,V,,,,,,,291006,,,N*47
$GPGGA,000015.039,,,,,0,00,,,M,0.0,M,,0000*58
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000015.039,V,,,,,,,291006,,,N*4F
$GPGGA,000016.032,,,,,0,00,,,M,0.0,M,,0000*50
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,3,1,12,20,00,000,,10,00,000,,31,00,000,,27,00,000,*7C
$GPGSV,3,2,12,19,00,000,,07,00,000,,04,00,000,,24,00,000,*76
$GPGSV,3,3,12,16,00,000,,28,00,000,,26,00,000,,29,00,000,*78
$GPRMC,000016.032,V,,,,,,,291006,,,N*47
$GPGGA,000017.032,,,,,0,00,,,M,0.0,M,,0000*51
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000017.032,V,,,,,,,291006,,,N*46
$GPGGA,000018.034,,,,,0,00,,,M,0.0,M,,0000*58
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000018.034,V,,,,,,,291006,,,N*4F
$GPGGA,000019.030,,,,,0,00,,,M,0.0,M,,0000*5D
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000019.030,V,,,,,,,291006,,,N*4A
$GPGGA,000020.035,,,,,0,00,,,M,0.0,M,,0000*52
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000020.035,V,,,,,,,291006,,,N*45
$GPGGA,000021.037,,,,,0,00,,,M,0.0,M,,0000*51
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,3,1,12,20,00,000,,10,00,000,,31,00,000,,27,00,000,*7C
$GPGSV,3,2,12,19,00,000,,07,00,000,,04,00,000,,24,00,000,*76
$GPGSV,3,3,12,16,00,000,,28,00,000,,26,00,000,,29,00,000,*78
$GPRMC,000021.037,V,,,,,,,291006,,,N*46
$GPGGA,000022.030,,,,,0,00,,,M,0.0,M,,0000*55
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000022.030,V,,,,,,,291006,,,N*42
$GPGGA,000023.033,,,,,0,00,,,M,0.0,M,,0000*57
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000023.033,V,,,,,,,291006,,,N*40
$GPGGA,000024.035,,,,,0,00,,,M,0.0,M,,0000*56
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000024.035,V,,,,,,,291006,,,N*41
$GPGGA,000025.034,,,,,0,00,,,M,0.0,M,,0000*56
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000025.034,V,,,,,,,291006,,,N*41
$GPGGA,000026.030,,,,,0,00,,,M,0.0,M,,0000*51
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,3,1,12,20,00,000,,10,00,000,,31,00,000,,27,00,000,*7C
$GPGSV,3,2,12,19,00,000,,07,00,000,,04,00,000,,24,00,000,*76
$GPGSV,3,3,12,16,00,000,,28,00,000,,26,00,000,,29,00,000,*78
$GPRMC,000026.030,V,,,,,,,291006,,,N*46
$GPGGA,000027.034,,,,,0,00,,,M,0.0,M,,0000*54
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,000027.034,V,,,,,,,291006,,,N*43
// tutaj zrobiłem inicjalizację odbiornika na nowo //
$PSRFTXTVersion GSW3.2.4-SDK_3.1.00.12-SDK001P1.00 *6D
$PSRFTXTETEN 20061207 EE X500*18
$PSRFTXTTOW: 0*09
$PSRFTXTWK: 1399*4B
$PSRFTXTPOS: 6378137 0 0*06
$PSRFTXTCLK: 96250*09
$PSRFTXTCHNL: 12*5F
$PSRFTXTBaud rate: 57600 *51
$GPGGA,235947.033,,,,,0,00,,,M,0.0,M,,0000*58
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,235947.033,V,,,,,,,281006,,,N*4E
$GPGGA,235948.038,,,,,0,00,,,M,0.0,M,,0000*5C
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,235948.038,V,,,,,,,281006,,,N*4A
$GPGGA,235949.035,,,,,0,00,,,M,0.0,M,,0000*50
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,235949.035,V,,,,,,,281006,,,N*46
$GPGGA,235950.033,,,,,0,00,,,M,0.0,M,,0000*5E
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,235950.033,V,,,,,,,281006,,,N*48
$GPGGA,235951.037,,,,,0,00,,,M,0.0,M,,0000*5B
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,3,1,12,20,00,000,,10,00,000,,31,00,000,,27,00,000,*7C
$GPGSV,3,2,12,19,00,000,,07,00,000,,04,00,000,,24,00,000,*76
$GPGSV,3,3,12,16,00,000,,28,00,000,,26,00,000,,29,00,000,*78
$GPRMC,235951.037,V,,,,,,,281006,,,N*4D
$GPGGA,235952.035,,,,,0,00,,,M,0.0,M,,0000*5A
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,235952.035,V,,,,,,,281006,,,N*4C
$GPGGA,235953.033,,,,,0,00,,,M,0.0,M,,0000*5D
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,235953.033,V,,,,,,,281006,,,N*4B
$GPGGA,235954.037,,,,,0,00,,,M,0.0,M,,0000*5E
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,235954.037,V,,,,,,,281006,,,N*48
$GPGGA,235955.035,,,,,0,00,,,M,0.0,M,,0000*5D
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,235955.035,V,,,,,,,281006,,,N*4B
...
I sygnału nie widzi
