[TenTec] Drift in Omni V

[Don and Diana Cunningham]

Hi, group!
I got a nice Omni V this week, my first.  It has considerable drift, more 
than I thought it would have since several use it for RTTY.  All I can see 
in searching the internet is a reference to "crystal aging".  Are there any 
pointers I am missing in my research as to what to look for to cure some of 
this drift?  I would like to use it on RTTY, but this one is not stable 
enough at present.  Thanks for any advice.  I really like the rig otherwise, 
and would like to solve this!
73,
Don, WB5HAK