I am a repair technician by trade (part time these days...). Mostly business band UHF / VHF.
If there's one thing I've learned, it's not to argue antenna theory with a Ham radio user (unless you want to get verbally beat up for a few hours
Did you make that jpole? Out of 300 ohm? Do you have a pic of it unraveled?
I'm spoiled i guess, I have a Globalstar at my disposal because we're a dealer. Tough I have NEVER wanted to take it, I just dont get that far out in the wildIt just goes to show how easily I forget to to the simple route.
You are correct it is a 300 ohm twinlead j-pole. I have made one but this is a commercial version. Create little antenna that takes up little space. I don't have a photo unrolled but there are probably plenty on the web. I'm not fanatical about antennas though.
Those Globalstar sat phones are pretty neat. Your a lucky guy.
KR