[TenTec] OMNI-VI question

[wt4t at reagan.com]

Have a beautiful OMNI-VI,new to me. I noticed the frequency readout is off about 
.68 on the readout. checked with my Sig gen and then with a zero beat on WWV. Went Thur the manual,nothing about this problem. Is this something that TEN TEC needs to fix or can I do this my self? I realize no big deal,but would like to have things as they should be. be grateful for any help on this.
73
dale wt4t