It can happen that you need to tune your recorder. Such a situation can be for example when you would like to play duet with another instrument.
To be able to do so you should follow the undermentioned steps:
1. Blow a note “A” with both instruments separately.
2. Meanwhile listen to it carefully which of the instruments is higher.
3. Pull the head of the higher instrument a little apart. You should now receive a lower tone.
4. Check again together with the other instrument, with blowing a note “A”. If there is still no match, try to adjust the head of the instrument so that it finally matches (pull it more apart if it was not enough, or push it back if the first pull was too much).
NOTE! If you pull it apart you will receive lower tone (as the size of the whole instrument will be increased), and if you push it back you will receive higher tone. That is the reason why you cannot tune the lower instrument, because normally you cannot push it more back than the basic position.