Trasmissione RTTY con PMSDR
Ho scritto al gruppo del PMSDR riguardo alla trasmissione con MMTTY utilizandondo il PMSDR con HDSDR. Questo è quanto ho scritto:
"Hi Lorenzo,
if you sync over CAT, the transceiver follow always exactly the "TUNE"-frequency (red line) of HDSDR.
But if you shift the passband filter in the lower spectrum, then the EXTIO-DLL can't read this shift value and process it for the CAT sync function.
In few words: the EXTIO-DLL don't know how many are shifted the pandbass filter in the lower spectrum, and there are no functions to read this value.
Therefore i suggest to shift by the same value also the audio band of your RTTY encoding software.
73 de
Martin
IW3AUT"
Ho provato a cercare qualche settaggio in MMTTY ma non ho trovato nulla.
Aggiornamento del 25/09/2012
Ho contattato IN3VVK esponendogli il problema. Speriamo che riesca a darmi qualche dritta.
"Hi all,
I would ask to the group about using SDR in RTTY transmission.
I have a PMSDR and I often use it in SSB QSO without problem. Sometimes I use digital mode but I have always have some problem during transmission.
In order to explain my problem better I post a video on youtube.
As you can see I use HDSDR and MMTTY. I use VAC and there isn't problem for receiving the CQ from ES5TF. The frequency tuned is 21.082.365 but the window are open at about 2125 Hz up in order to catch the right signal for MMTTY.
When I transmit the RTX (a Yaesu FT-950) go on transmission on the tuned frequency but not on tuned frequency +2125 Hz. I transmit where is the red line. My RTTY signal is 2125 Hz down the desidered frequency and ES5TF doesn't hear me.
I know that is not a PMSDR strictly related problem but I hope that some user can help me in this (small) problem.
Thank you very much in advance.
Lorenzo, IN3EJN"
poco dopo Martin mi ha risposto:
if you sync over CAT, the transceiver follow always exactly the "TUNE"-frequency (red line) of HDSDR.
But if you shift the passband filter in the lower spectrum, then the EXTIO-DLL can't read this shift value and process it for the CAT sync function.
In few words: the EXTIO-DLL don't know how many are shifted the pandbass filter in the lower spectrum, and there are no functions to read this value.
Therefore i suggest to shift by the same value also the audio band of your RTTY encoding software.
73 de
Martin
IW3AUT"
Ho provato a cercare qualche settaggio in MMTTY ma non ho trovato nulla.
Aggiornamento del 25/09/2012
Ho contattato IN3VVK esponendogli il problema. Speriamo che riesca a darmi qualche dritta.
