I've got the analog vers of bottom one.
Had since Sat first came out. (pre Vast)

I always find that with the chart from net.

Preset elevation of req'd sat (just like your Sextant.)
Set stand to bearing of sat, req'd.
and it only takes a coupla seconds to find.
SLowly scan from l to R while rocking a few deg's up and down. normally does it.

Sometimes fine tune with rotation of LNB.

If you have problems. Go and have a coffee.
Then try again.

Knickers in twist?.Cranky. You'll be there all night.

Reeeelax.

Or do like me.
Leave it at home and watch movies\tv shows on HDD.

Old Kenwood HF reciever for real Airports local weather. and BOM on phone.
Listen to mates at sea with 30 ft, 2 to 30 meg cable out too.