HP 2648 running at 50 hz

[locsharp]

Hello,

I got an HP2648 terminal from the US.

I read in the manual that if you run the machine with 230V 50Hz power ( like we have in Europe ) beside changing a couple of fuses , you have to also replace the display timing card crystal.
The one required is 17.55 Mhz but I am not able to find this anywhere.
Is there a way to solve this ?

Thanks

Ste