Here is the other transmitter being replaced. This a Continental Electronics 316B. This is a 10,000 watt transmitter and until a few years ago was a backup in case we had problems with both the DX50 and the MW50. This transmitter was installed in 1961 and for a time was the only transmitter that was powered by the generator. When it was installed, CBS also installed a 60KW generator inside the building. This generator was just big enough to run the 316B and the building, but not big enough to run the main transmitter, the General Electric BT25A. Years later, a larger generator was installed that could run the 50KW main and aux transmitters and allowed KCBS to operate at full power during a power failure.
This transmitter also used a new type of modulation called 'Screen Grid Modulation', but this caused the transmitter to be very in-efficient and use more AC power than other 10KW transmitters of the time and this type of modulation never really caught on with other manufacturers
KCBS-KLLC-KITS ENGINEERING DEPT