See for any additional tuning information. The picture below was copied from the same site.


The KF163 is normally programmed using a diode array chip S353 as shown below but can just as easily be done with a collection on diodes (1N4148 or 1N914) mounted on an IC socket.

Control Pins.

Pins 2 to 11 are used as control pins. Pin 2 goes low when you are receiving on channel 1, Pin3 goes low when you transmit. Pins 4 and 5 are the same for channel 2 and the pattern is repeated up to channel 5.

As diodes are used to ground certain pins then you mast make sure that the diode ‘points’ to pins 2 to 11.





Frequency Steps

If pin 28 is connected to pin 1 via a diode, anode to pin 28, then the channels work in 12.5K steps and that is the version described here.


The programming is as follows.


Coarse Setting.

For setting the large frequency increments you use the B1 to B8 set of pins. It is normal binary at 1.25MHz per bit, so if B1 goes from low to high the frequency goes up by 1.25MHz.


Fine Setting.

For setting the smaller frequency increments you use the A1 to A7 set of pins. It operates in the same way as the B set but the increments are 0.0125MHz, 12.5kHz.


If a pin is open circuit it is logic 1, when shorted to its control pin by a diode it is logic 0.






Worked Example.


To protect the Cadet channel freqs the example is for a generic 156.800MHz.



B8, B2, A7, A5, A2 and A1 are shorted to TX1 (pin3) by diodes.

This leaves B7 (80MHz) + B6 (40MHz) + B5 (20MHz) + B4 (10MHz) + B3 (5MHz) + B1(1.25MHz) + A6(0.4MHz) + A4(0.1MHz) and A3(0.05MHz) at logic one = 156.800MHz.



As the receiver Intermediate Frequency is 21.4MHZ low, then the synthesiser must be set to 21.4MHz below the required receive frequency.

For the example above it would be 135.4MHz

B8, B5, B2, B1, A7, A5, A4, A3, A2 and A1 are shorted to RX1 (pin2) by diodes.

This leaves B7(80MHz) + B6(40MHz) + B1(10MHz) + B3(5MHz) + A6(0.4MHz) at logic one = 135.400 MHz.