Dilshan Jayakody published a new build:
The 1750Hz tone bursts are often used to trigger repeaters. There are several methods to build 1750Hz tone generators which including TC5082 divider, using MCUs, etc.
In this post, I present another 1750Hz tone generator which I built using 74HC4060 high-speed 14-stage binary ripple counter and 7.168MHz crystal. In this design, 74HC4060 is used to drive the crystal and divide its output by 4096. By using 7.168MHz crystal, this circuit produces 1750.0Hz square wave output with a 50% duty cycle.
See the full post on his blog.
from Dangerous Prototypes http://bit.ly/2Z2Offd