The NE602 is a low-power VHF monolithic double-balanced mixer with input amplifier, on-board oscillator, and voltage regulator. It is intended for high performance, low power communication systems. The guaranteed parameters of the SA602A make this device particularly well suited for cellular radio applications. The mixer is a Gilbert cell multiplier configuration which typically provides 18dB of gain at 45MHz. The oscillator will operate to 200MHz. It can be configured as a crystal oscillator, a tuned tank oscillator, or a buffer for an external LO. For higher frequencies the LO input may be externally driven. The noise figure at 45MHz is typically less than 5dB. The gain, intercept performance, low-power and noise characteristics make the SA602A a superior choice for high-performance battery operated equipment. The later NE612 or SA612 is an improved pin for pin equivalent.
I'm going to leave the rest to see if anybody actually reads these pages and asks me for some oscillator circuits. This would include both fixed and variable oscillators as well as fixed and variable crystal oscillators - all in the HF region.
Note that up in the VHF region it is almost impractical to design variable oscillators, the drift will kill you. I'd recommend using 3rd or 5th overtone oscillators using crystals, see "Figure 9. Typical Application for Cellular Radio" from the 602 mixer PDF data sheet.
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