I have a 73 Ambassador cornet I got a few months ago and in excellent condition. I like to play it for it's sound and ease of playing. However, the horn will not tune to concert Bb on a tuner, unless the main tuning slide is pushed in to a hair'sbreath gap from all the way. The other slides are in and it has an adjustalbe 3rd valve ring. I use a couple of Bach's, a Jet Tone Al Hirt, or even the OE of my 53 Roth, but it is still the same. Plays in tune, but I was wondering if any one had similar experiences or ideas. My other cornets and trumpets don't have that situation. Thanks!