Why is Service Bulletin 4 significant for the KTR-953?
KTR-953 Service Bulletin 4 addressed the replacement of the original crystal over assembly in the unit with a more accurate, higher reliability Temperature Compensated Crystal Oscillator (TCXO) assembly. The TCXO provides instant-on operation eliminating the need for the 2-3 minute warm up time as with the original crystal oven assemblies. The effectivity for this SB is as follows: • KTR-953 P/N 064-1015-00 units with serial number 3196 and above have SB 4 incorporated during original manufacturing. • KTR-953 P/N 064-1015-00 units with serial numbers between 2940-3195 have SB 4 incorporated during original manufacturing but were not stamped. • KTR-953 P/N 064-1015-01 units with serial number 25644 and above have SB 4 incorporated during original manufacturing. • KTR-953 P/N 064-1015-01 units with serial numbers between 25350-25643 have SB 4 incorporated during original manufacturing but were not stamped. The cost to incorporate SB 4 is approximately $2000 (2010 pricing). While KTR-953
