Making the VFO PLL for High Frequency

Homebrew multiband SSB transceiver part 6

Programmable IC TC 9122 DEVIDER was only able to divide frequency up to approximately 14 MHz at 6-volt voltage.
For the ability devider is 1 to 3999.
Therefore, if the frequency that must be shared exceeds the capacity it should be held down Conversion, which required pre-mixer.
For example the 5266 KHz IF frequency to be work in the 14250 KHz band is required to vfo frequency 14250 + 5266 = 19516 KHz PLL so must be made
who worked around 19516 KHz.

In this project the set Oscilator Reference 1KHz, was
Xtal oscillator taken 16 MHz. Because 16MHz crystal
available lots in the market.

From the block diagram above can be calculated that the frequency of
into the TC 9122 to work on 14250KHz is 19516KHz -16000KHz = 3516KHz. 3516 numbers are still under number 3999 of the divider TC 9122. So the 14250KHz working frequency must be programmed for the TC9122 to 3516 that if written in BCD: 11 0101 0001 0110
Control circuit used for IC CD4029 up / down counter that can be programmed.

To move UP / DOWN is used two IC CD4011 also as debouncer. Encoder dial can
use mechanical systems that available in the market. Dial encoder can be used from the component MOUSE computer unused / damaged.

To make the VFO on the other band, the market can be found in the crystal
with frequency 3, 5, 6, 8, 10 and 16 MHz that can be tried to achieve the desired frequency band