The resistor named R can be replaced by a 50 Ohm type if the power supply is 5 Volts. The dividing ratio can be programed with IC2. For the ratios see table 1. Example: If the input signal has a frequency of 10MHz, the crystal frequency output is 10.240-10.000=0.24. Now looking at table 1, we see we can make 24 by combining the 8 and 16 program switches (pin 11 and pin 12 closed to Vcc). By trimming coil T the output will lock to 10MHz. To use this PLL in the 3 meter band (100MHz), divide the oscillator frequency by 10. Next feed this signal to pin 4 from IC1 by a 8pF capacitor. The adjust voltage coming from IC2 pin 5 should be connected to the oscillator's varicap by a 4k7 resistor. As described here, the PLL will make frequency stepping of 10kHz, to change it to 5kHz apply around minus 9V to pin 4 from IC2. When using this PLL in the 3 meter band, this will result in stepping of 50kHz instead of 100kHz.

Build your own LC Meter and start making your own coils and inductors. This LC Meter allows to measure incredibly small inductances making it perfect tool for making all types of RF coils. LC Meter can measure inductances starting from 10nH - 1000nH, 1uH - 1000uH, 1mH - 100mH and capacitances from 0.1pF up to 900nF. The circuit includes an auto ranging and "Zero Out" function to make sure the readings are as accurate as possible ... [more]