0-22 kHz Oscilator

I need a simple 0 - 25 kHz oscilator. No need to be a very stable one becose im going to drive the output in a specer (yes im making an electronic dog wistle).Plese no 555 timers i dont have them but i have a whole bunch of transistors. I made one simple 2 transistor oscilator(It was originaly a led flasher) but it kiled the output at 17 kHz (or did i somting wrong).

I want to make it adustable whith a potencimeter(i have 10K and 120K ones).

There are some oscillator related circuits near the bottom of this website, might be somthing useful, then again there might not.

https://www.commlinx.com.au/schematics.htm