Here's the schematic for the CRK5A from the RCA field Service manual. They don't call out native osc frequency, but take note of the frequencies next to the remote function switches. Somehow I missed those the first time I looked at it. Also, on the CTC-9-11(CRK3A-B,) they call out 19.125kc as the native oscillator frequency. CRK3A-B Looks like the same basic circuit using the 2N406.