Connection via sound card

[skyhawkgr]

Hi,
im using a sanwa vanguard vg4r transmitter and i want to connect it to the pc using the sound card.
this tx is not equipped with a buddy box connection although as ive seen in varius pages with radio connections it should (as ive seen in photos my tx is similar with airtronics vanguard vg4r which probably comes with buddy box, does anybody know whats the difference between sanwa and airtronics company?)
anyway i found the ppm signal inside the tx and i have some questions......
is it preferable to connect the transmitter to the sound card through the microphone or the line-in input?
as ive seen in other posts it is better to use a mono audio jack.....
the ppm signal pulse is +6V high.
is that voltage able to damage my sound card, will it cause other problems?

ty in advance...

[shaul_eiz]