I bought a tenor recorder recently. It's a Mollenhauer Canta Denner with extra keys on G / F as well as C / C sharp because I have small hands and couldn't manage the keyless ones. It makes a lovely sound and I'm very pleased with the instrument. It does tend to clog quite quickly though and I have to suck out the moisture during rest bars. Is there a way of producing less moisture when I play?? Also low F and F sharp are weak notes compared to the surrounding notes - is this normal? Are there alternative fingerings that would produce a stronger sound? Any advice gratefully received!

I'm trying to imagine the extra keys you speak of, for G/F? I don't know really good advice for prevention of clogging - I loathe anticondens, it tastes disgusting when you end up having to suck back (because it doesn't prevent the need for it totally) - but you produce most saliva (apart from during a meal itself) after eating, and after doing teeth, so best to avoid those two activities directly before practice. Weak notes can be a matter of the instrument's internal gremlins, but it's worth checking that the pads of the keys you have are sealing properly. Certainly when buying a new instrument, I do go through its range looking for duff notes and poor tone: when I bought my bass, I'd been intending to buy one in cherrywood, but on the day, the rack of cherry instruments all had weak low As, as did all but the one pearwood one I ended up getting instead.

Another problem I do have with weak notes relates to not checking properly that I've really got the various sections together for the best ergonomic fit for my hands on assembling instruments - and that happens to me embarrassingly often .

As far as alternative fingerings go, difficult to advise - it's more a question of fiddling around and seeing what you find to work best yourself, I'm afraid, but a good starting point would be one of the extended alternative fingering charts. I know that one of Walter van Hauwe's books has them in, but can't at the moment remember which volume....

This is a bit of guesswork, given I can't see you play your instrument, but two possibilities strike me:

First to check, as anacrusis suggested, that the pad on the G key in particular is sealing fully.

And then to look to your right hand position to ensure that you are covering your unkeyed holes properly.

It is possible that in trying to reach round your extra keys, you need to shift your right thumb a fraction down.

With any of my tenors (mainly unkeyed) and both my basses (keyed), the finger that is hardest to get into the right place is the right hand ring finger, and that tends to depend on getting my thumb position just right.

A tip I was told to get the right thumb in a good position is to place the instrument on a table or the floor in front of you with the tone holes underneath. Slide your 3 RH fingers under onto their respective holes then place your thumb where you need to to pick up the instrument with just your RH. Making sure when you are playing your right wrist is roughly perpendicular to the instrument also may help.

I'm guessing keys for 3 and 4, as well as the usual split key for 7.
Aha, found a picutre of the Mollenhauer Canta comfort, can get it with and without knick:

ooh, thanks, Maizie - I'd done some hunting around but hadn't managed to find that. I'd been puzzled because whilst I can see the point of one for the G, the bit for F wasn't fitting my preconceptions about what is hard to stretch....and yes, more than ever, making sure of good pad seals seems to be... (if you'll forgive the pun) key.

I have relatively slim fingers, despite large hands overall, and find it difficult to cover some of the holes in bigger instruments neatly, and this is why hand position is so important. If the tenor also has a thumb rest, you'll need to make sure it's in the right place for you: here's hoping that if you have one, it's also adjustable, as the one on my bass is, whisker.

That's great. Thanks all of you for the advice. I need to go away and experiment now. The photo you found, Maizie, is the model I bought but without the knick. There is a thumb rest and it is adjustable so I'll have a play around. It's great to be given some help as I am self-taught on the recorder - thanks for your time.