IDD CI24 ECONO MM Penta 1.20 Galaxy II
1.2Mtr Polar MTG yes it has been on the arc for 25 years and is now fixed on 13 East using two pairs of rusty molegrips. Unlike me they never groan but always perform.
Your stb is made by Astrovox their website here contains lots of interesting downloads for your stb and there is a manual although it is in French which may give you the answer you seek. If you do manage to solve your problem please come back and post the answer for others to use.