ILER-DDS V2.1 VFO/DDS.
Page 13
ILER-DDS WIRING
The wiring is very simple but is important how you do it.
We don't want it to just work......
it should work PERFECTLY!
The position and wiring of the ILER-DDS will strongly affect the reception of noises in the receiver (see
"Digital noises").
Some advices to be taken into account:
For the output signal use good quality, fine coaxial cable (ej. RG-174).
Place the encoder as close as possible to the ILER-DDS block. If it is far away, and wires go by
or over the transceiver circuit may introduce switching noises whenever the encoder is used.
Even the supply wires to the connector or the ON-OFF switch may affect the nose level. Try with
only one wire, the positive one, as the negative will be routed through the coax shield.
It is not advisable to wire the LCD.
The LCD should be sandwiched with the control board!
By the way: Do not forget to place two 100 nF capacitors directly between the encoder pins!
If need be, you will have to make changes on the wire routing or the wire type; it will be a "trial and error"
procedure.
Sometimes low level noises detected may disappear when the antenna is connected, and do not
affect adversely the reception. In that case: you don't have to fight them!
By following the previous advices, the wiring of the ILER-DDS is very simple. Please check the drawing:
The wiring described is from the back of both the encoder and the control board.
Your ILER-DDS kit can incorporate two types of rotary encoder. The two models are the same but have
their terminals positioned differently. Type A has the encoder terminals on top and the "push-switch" are
below. The type B has all the above, the encoder terminals are shorter and the switch are longer.
