Originally Posted by
ar-t
Anyway, back to the original issue.........
Guys, I am probably the only person any of you will run into that has experience designing low-jitter oscillators. If sticking a different crystal into a circuit was all it took, anyone could do it. But, it is far more complicated than that.
Most crystals perform about the same, because they are all made about the same. And that is: cheap.
To get any less phase noise (jitter) than you already have, it will cost $$$. You can not, or will not, get a "typical" crystal that will perform any better. Even if you called up someone, like IQD (in your neck of the woods), they are not going to budge unless you start to talk about making thousands. If you do find someone who will make a one-off, without a large minimum, or price tag, what do you think they will sell you?
"Why don't you want a HC-49/s? What is wrong with them? That is what everyone uses these days."
(At this point, you know you are talking to a salesman, and you might as well talk to the wall.)
Just like pretty much everything else, these days, crystals have been relegated to "commodity" status. Which means no one makes their own, as they outsource to Asian suppliers. Which is why they are all cheap, and perform that way.
In fact, I will stick my neck out further, without even seeing what is inside your TT, and go as far as to say if you do get a "new" crystal that it will be worse, than what you have.
Guessing what era that TT was made, I will wager it uses a HC-49 holder. Which is the typical holder used in commercial electronics, back then. They are ok. Biggest flaw is it is a resistance-weld holder. Which is going to limit performance, as it will not be as clean (internally) as one would need, for really good performance.
And you are going to step down, to a HC-49/s.
I am sure there is 1000 things you can do, to improve your TT. Changing the crystal is not one of them.