Hi all,
I have been prowling these forums for some time, and thanks to the stories and posts here (especially the links to tutorials on manual targeting) I had a rekindled interest in SH4 (and SH3, to a lesser degree).
I played 'vanilla' for some time, then I got a copy of Trigger Maru 1.7.2, installed it, with some minor edits (I'm a pilot myself, and in flight sims I never look for subs underwater

) so in my edits of TM, I removed all the new 'sensor configs' for the planes before enabling in JGSME

.
Anyway, I had a similar experience as some of the posters here. I reloaded a game for twenty times, never got a tower upgrade (I first made sure there was one available, of course

).
So I started poking around in the savegames, and I found an entry in the following file (savegame = 00000000, just as an example):
\Documents\SH4\data\cfg\SaveGames\00000000\UserPla yerSettings.upc
[UserPlayerSettings]
ID=UserPlayerSettings
NameDisplayable=UserPlayerSettings
RandomSeed=-849660181
I found the negative random seed strange, so I changed it to a positive number (I found the same number in ALL my savegames, anyone know what generates this random seed???)
After changing the random seed to:
RandomSeed=849660181
I got a tower upgrade after two reloads of the savegame!!
I suspect that the negative random seed prevents, at least, those tower upgrades, because I did get a sub upgrade (which was the USS DRUM, EVERY SINGLE TIME!!!, strange, huh...:hmm: ) .
I don't know if this editing the random seed fixes the absence of tower upgrades for everyone, but it seems to have worked for me.
APPENDIX: For TM 1.7.2 I did a complete reinstall (1.0 ->1.4 -> TM1.7.2), but I kept my savegames, which probably also means I kept my 'random seed', which I think led to the absence of tower upgrades. So, does every install of the game create a single random seed which stays throughout all of the gameplay????
I hope this will help some people get the tower upgrades without 'hacking' the availability dates etc...
Good luck, I'm departing in USS Thresher from Fremantle with her tubes full of Mk23s with a brand new cut down sail bristling with 20mm whoop-***
Greetz,
@lantis