Tracking Generator


This is a tracking generator for the Tektronix 492 based on KE5FX's design. It takes the place of a TR-503 tracking generator but has a different architecture. The design is essentially the same as KE5FX's, but uses attenuator/amplifier pairs instead of isolators and has a different PLL circuit for generating the 110MHz LO.

I had trouble keeping signals from the tracking generator out of the Tek 492's LO outputs when using isolators. This caused the 492's noise floor to increase dramatically. I replaced the isolators with attenuator/amplifier pairs to provide more isolation over a wider band.

There is currently no output leveling loop so the output is a bit bumpy.

Output trace: