H A R D W A R E I N S T A L L A T I O N
C H A P T E R 1
Note:
Although not necessary, if you prefer to connect your paddles to a
serial port on your PC you may do so using the pin-out shown in
Table 4: PC Serial Port Pin-Out
Serial
Port Pin*
Keyer Signal
4 (DTR)
Common
6 (DSR)
Dot
8 (CTS)
Dash
* Assumes a 9-Pin connector
(9) External Keying Lines (AMP RLY TX1, TX2 & TX3)
These three independent keying lines can be used to key external devices such as linear power
amplifiers or transverters. One or more of the keying lines can be used at any one time, can be given
a delay and can be assigned on a per band basis on the Antenna Form (see page 150). For example,
you may have an HF amplifier that covers 160-10 meters and another amplifier for 6 meters. You can
assign
TX1
to bands 160 -10 meters to key the HF amplifier and
TX3
to 6 meters to key that
amplifier when you select the 6 meter band.
These keying lines each use an open collector Darlington transistor switch that is rated at 400mA,
50VDC maximum. To ensure that your amplifier keying circuit does not damage the Darlington
transistor switch, it is safest (even for modern amplifiers) to insert the circuit shown in Figure 3 below
between each of TX1, 2 and/or 3 and your amplifier(s).
Figure 3: Protective PTT Circuit Between TX1-3 and Amplifier
(10) External Frequency Reference Input
Accepts input from an optional 10MHz, 0 to +10dBm reference source, such as a GPS disciplined or
high precision clock source. This enables greater frequency stability for those operators requiring such,
e.g. for VHF+ operators operating in the GHz range.
[The rest of this page has been left blank intentionally]
9
2003-2008 FlexRadio Systems
