Max038 High Frequency Waveform Gen.
The Maxim Max038 is used in many function generators as a single chip Sinewave, Triangle Wave and Square Wave generator which is phase locked to a master oscillator. This chip is used in the BWD604 series minilabs to give a good stable output signal with low distortion at the lower Frequncies. 2% THD at 1 Mhz, rising to 10% THD at 20 Mhz.
The small board shown at the top is a Max038 function generator selling for $57 on eBay.