MC3372 Datasheet, Motorola

acitance probe or a “sniffer” to view the wave
  – form without altering the frequency. Typical level is 450 mVpp. VCC Waveform 1 OSC1 2 OSC2 2 OSC2 15 k T.

OPERATING CONDITIONS VCC = 4.0 Vdc, RFIn = 100 µV, fmod = 1.0 kHz, fdev = 3.0 kHz. MC3371 at fRF = 10.7 MHz (see Figure 11). Pin 1 Symbol OSC1 Internal Equivalent Circuit Description The base of the Colpitts oscillator. Use a high impedance and low c.