· Distinguished SOTW Coffee Guru
Like almost anything this has been dealt with (with many different opinions) before and in many threads from different angles (these are extracts from one of the best threads, in my opinion)
These things are absolutely related.
Sounds like you are over venting with the F key. Altissimo using that key is picky, and if it is too open, it will almost always crack. Try this: Take a business card, or index car. Stick the corner of it between the F key pad, and tonhole just enough to make a small opening. Now, try your altissimo G (using your index finger on the first pearl, not the front F key). It probably will respond a bit better, though perhaps not perfect at first.
I would ask your tech -why- he makes the F key open as much as with the palm key. To me, this seems very odd.
Steve's advice is good advice. I always mess with the height of the front F when doing repads and overhauls- every horn responds differently and will work best with a certain height. Even horns within the same serial range of the same model will respond a bit differently to the height of the front F, and only playtesting lets me know what each particular horn responds to well.
I usually set up the front F to open the F key to around half the venting of the F key when it's opened normally - so if the F key venting is 4mm, the front F will open it to around 2mm.
It's a personal thing, but start from this point and experiment by adjusting the front F to open the F key by more or less until things speak easily for you.
If your front F mechanism doesn't have an adjustment, you'll probably have to bend the end of linkage piece down to put more double action between the front F key and the linkage, or to alter the leverage by bending the linkage piece towards the front F key/LH main action key barrel will reduce the opening of the F key, or a combination of both until things are right.
Not so easy a DIY job on Yamaha tenors (post YTS-61) without the adjustable front F key, but it can still be done.