[amsat-bb] Ten Tec 2510 additional frequencies?

Hello.

I am looking for a way to add additional frequencies to a Ten Tec 2510. The manual indicates that additional crystal oscillators would be made available to extend transmit range up to 437.0 Mhz when available, but I havn't been able to find out anything on this. Is there anyone on the list that has done this modification or has a circuit board diagram or templete?

Thanks and 73,

James, AA5AO