When ive spoken to the shop manager at the place that i use for my table, ive heard him pronounce it with a hard O...phone. I cant say if thats right or not bu thats how ive heard it said.
I also just Googled that question & came upon a post on AudioKarma where a guy who speaks german said that if your pronouncing the "fon" as "phone" then your saying it right.
I hope these 2 examples of mine are correct!!
FYI: i just recently hooked up my dads old Lenco he had up in the garage setting for 20yrs or so. Works & sounds great!! Has gotten me back into vinyl. I have maybe 60 records & have been loving them. Im gonna go back to the shop i like & have them redo the wires because they can cut-out if moved. Also want to install a new cartridge & tonearm.