my call is 16hs1000 i am staying until the end of the week in svalbard wich callsign must i use

Try a new 171HS????

73 de 153HS1129/Len

Normally the prefix of the guest-country first, separated by "/" (stroke/slash) and THEN your own callsign.

73 and good DX from Jörg :-)
JO31ok
Bochum / Germany

Yes but only for operators with an amateur radio callsign. Does not apply for HS callsigns DE G0THD

Uh yes, that's correct of course.

Mhm, could be a problem at HamSphere cause of the (normal) Grid-Locator, IP-Ranges and home QTH and all their dependencies.
Maybe a ticket to the HS support should be the best way to get a solution. But the effort is very large for only a couple of days in a foreign country, I think.

73 and good DX from Jörg :-)
JO31ok
Bochum / Germany

True, but Freddy has been active from Svalbard with 171HS100, so I guess he got it sorted :-) DE G0THD