Oscillator experiments continued

In my quest for a stable wide range VCO, I have found this push-pull franklin to be promising. Placing a varicap diode from each of the hot ends of the coil, the distortion that would normally be caused by using varicap tuning is cancelled out. The emitter resistors can be replaced with a single resistor, but by splitting it in 2 and strapping the emitters together through a resistor introduces some negative feedback to reduce distortion and stabilise the amplitude. I comfortably get a 4:1 tuning range from this set up.

I tried a similar circuit but with a single winding in T1 collector circuit and T2 collector grounded, but even with back to back varicap diodes the waveform was badly distorted. I'm going to try current sources in place of the emitter resistors next.