Yaesu FT-100D Operating Manual page 24

Installation
ACCESSORY INTERFACING
found on an FM Service Monitor used in a communications service center). In most cases,
the Packet Data Input level (set via a potentiometer inside the TNC) must be adjusted to
provide a deviation of ±2.75 kHz (±0.25 kHz). Check with your packet node's sysop if you
have any questions about the appropriate deviation level for your network.
The setting of the 1200 bps Packet Data Input level is much less critical, and satisfac-
tory adjustment to the optimum (±2.5 - ±3.5 kHz) deviation can usually be done "by ear"
by adjusting the TNC's 1200 bps TX Audio Level potentiometer so that the outgoing
packets (as monitored on a separate VHF or UHF receiver) are slightly lower than the level
of your speech. If you have the optional MH-368SJS DTMF Microphone, set your TNC's
tone output to be about the same level as that of the DTMF tones produced by the MH-
368SJS.
The "RX 1200" and "RX 9600" lines are fixed-level audio outputs, not affected by the
setting of the AF (GAIN) control.
CW Key/Keyer Connections
All commonly-available keyer paddles should work perfectly with the built-in Electronic
Keyer. The wiring configuration for the paddle is shown below.
For straight-key operation, only the tip and shaft connections
are used.
Note: Even when using a straight key, you must use a three-
conductor ("stereo ") plug.
If
a two-conductor plug
is
used,
the key line will be constantly shorted to ground
When using an external electronic keyer, be absolutely cer-
tain that it is configured for "positive" keying, not "negative"
or "grid block" keying. The "key-up" voltage of the FT-J 00
is +5V, and the "key-down" current is only about I rnA.
For CW automated keying using a personal computer, with an
external memory keyer providing for manual sending, it usu-
ally is possible to connect the keyed lines together via a "Y"
connector. Check with the documentation accompanying your
keyer and your
contest/DX
software for any cautions which
need to be observed.
22
FT-IOO
MICRO MOBILE OPERATING MANUAL