AFSK Output Level
The DE1200 modem is shipped with the audio output level set for 50 millivolts p-p.
This
is the proper drive level for the dvr 2-2 radio from Kantronics.
If
your radio
requires a different level of drive, you
can
move jumper J3 to the low position (center
pin and pin
L)
to provide 10 mv p-p, or you can remove jumper J3 to provide 2 volts p-p
of audio drive.
If
none of the factory jumper settings provide the proper drive level for
your radio, you may
install
a lOK potentiometer at R18 to allow adjustment from
about 10 millivolts to 200 millivolts p-p. You may optionally remove resistor R16 (lOOK
ohm) and
install
a lOOK ohm potentiometer at R18, allowing adjustment of the audio
output from 10 millivolts p-p to a maximum of 2 volts p-p.
If
you
are
connecting the DE1200 modem to a hand-held radio, refer to the Section on
"Interfacing the DE1200 to Hand-Held Radios" in
this
manual.
Equalization
There
are three
jumper-selectable equalization positions available, allowing
optimum performance with your radio. The unit is shipped from the factory with NO
EQUALIZATION selected (jumper Jl on the center post and N). Partial equalization
can
be selected by placing the jumper
on
the center post and P, and full equalization is
selected by removing the jumper.
If
you
are
using audio directly from the discriminator
of your radio, no equalization is the required setting. For those using audio from the
external speaker jack, you may need to select partial or full equalization. The best
selection
will
be determined by observing the retries over a period of time, and the
fewest retries indicates the correct setting.
Interfacing the DE1200 to Hand-Held Radios
The DE1200 modem is shipped ready to connect to most mobile or base radios. If you
are
to
use
a hand-held radio, jumper J2 should be moved to connect the
center pin with the pin marked
HT.
In some cases, you
will
require a different value
of resistor in the Push-to-Talk circuit as described below.
ICOM hand-helds (2AT, 02AT, 2GAT, etc)
Move jumper J2 to the
HT
position. Next connect the following pins from the DB-15 to
your
HT
as
listed:
DB-15
Connect
to
6
1
No connection
2
Earphone jack tip
3
Microphone jack tip
8
No connection
9
No connection
10
No connection
11
Earphone jack shell
DE1200 Modem
April
3, 1990
e
Copyright 1990, Kantronica Co.,
Inc.
All Rights Reserved.
Duplication of this manual without permission of
Kantronica Co.,
Inc.
is prohibited.
