8
4. LINE OUT Jack: This 3.5 mm. (1/8”) stereo jack outputs the Line Out port of a
selected transceiver. Normally, the tip would be the left or main receiver line output and
the ring would be the right or sub-receiver output. The jack is typically used to interface
a transceiver’s line output to the input of a computer sound card or TNC.
5. AMP RELAY (3) and AMP ALC (3) jacks: These RCA phono jacks should be
jumpered (use shielded phono cables ) to the relay and ALC jacks of the station’s linear
amplifiers. Because the Amp Relay outputs are buffered by a solid state switching circuit,
the user need not fear compatibility problems between a selected amplifier and
transceiver.
6. AUX1 through AUX4 Jacks: These RCA phono jacks are spares that can be
used for any control purpose by the user. The StationPro routes these jacks to spare pads
on the breakout pod associated with a selected transceiver. They can be used for, e.g.,
band data switching.
7. SPKR-L and SPKR-R Jacks: The station’s speakers should be connected to
these RCA phono jacks and are routed by the StationPro to the speaker output ports of a
selected transceiver. Normally SPKR-L would be used for the main receiver’s speaker
and SPKR-R for the sub-receiver’s speaker. These jacks are disconnected when
headphones are inserted into a front panel jack on the StationPro.
8. PTT Jack: This RCA phono jack is wired in parallel with the PTT line on the
microphone and also with pin 3 of the Packet/RTTY jack. Grounding this line actuates
the PTT circuit of the selected transceiver. A typical use would be to connect a foot
switch to this jack. Note that some transceivers ground their PTT line when transmitting,
so that this jack could be used in this instance for, e.g., external receiver muting.
9. +12 CTRL Jack: This RCA phono jack o12VDC when the StationPro’s
power switch is turned on. The +12V is in series with a 1000
Ω
resistor, which limits the
short circuit current to 12 mA. Because of the series resistor, the jack
cannot
be used to
power 12V accessories. This switched jack is intended to control a (user-supplied) solid
state AC power relay, which can be used as a master station power ON/OFF relay. Below
is a sample circuit diagram using an SPST solid state AC relay. Any solid state relay that
operates with a DC control control voltage of 3-15V (or more) can be used. The relay
should have a load current rating of at least 25A. A DPST solid state relay can be used if
the builder wishes to switch both sides of the 120VAC line.
A convenient way to make this relay master power controller is to mount the solid
state relay in the bottom of a deep duplex outlet box, available at Home Depot or any
electrical supply store. An ordinary duplex outlet (two 120VAC receptacles) is mounted
on the face of the box, and a heavy duty AC power cord exits through one of the side
holes. A fuse holder and an RCA phono jack mount on the other side of the outlet box. A
shielded phono cable connects this phono jack to the 12V SWITCHED jack on the rear
panel of the StationPro, and an outlet strip for the station equipment plugs into one of the
two duplex receptacles. The other duplex receptacle can be wired directly to the 120V
