Also would have to pay not less, called the is a very big deal. It is interested or not -But now you can make it yourself easily, with a little investment. Try do like the features of this project. The heart in working of this circuit is the IC XR-2206. 1. Voltage control oscillator (VCO) that has the frequency out to, depending on the value of the capacitor between pin 5-6 and the resistor between the pin 7-8. The square wave signal will has signal strength is about 12 volt peak to peak, So if you want to use TTL circuits using voltage 5 volt.
Also must add dc converter circuit with IC-SN74LS00. All equipment except the power transformer 12volt, can be assembled onto the print, as shown below. You should solder correctly and successfully. After a successful check. Sure that the power supply to the circuit. And adjust the circuit.