- 14 -
is +3 Vdc. A valid
T/R CTRL
input disconnects INPUT
B
and bypasses INPUT
A
directly to
the RX OUT. Antenna voltage is also removed from input ports when
T/R CTRL
is activated.
This reduces chances of damaging the
NCC-1
when the receiving antennas are located close to
transmitting antennas and allows the DX Engineering
ARAV
series active antennas to mute,
protecting them from transmitted energy.
Internal Jumpers
The
NCC-1
motherboard has jumpers that configure the antenna jack power and transmitter muting
options. With the unit unplugged and no power connected, remove 6 screws on each side of the
cover and lift it off.
To configure the jumpers, turn the
NCC-1
so the components match the orientation of
Figure 1
.
The Default jumper positions as shown:
HD1
– Antenna A Power:
OFF
HD2
– Antenna B Power:
OFF
HD4
– Antenna Power Source:
13.8V
HD5
– TX Mute Polarity:
NOR
or Low (Most transceivers) Both Jumpers Installed.
Figure 1: NCC-1 Jumper Locations
The jumpers are small plugs that fit over and connect two of the pins on the associated header. The
jumper is removed by pulling straight out and installed by aligning with two pins and pushing
straight in to fully seat the jumper.
