Icom IC-703 - D Adjusting the Transmit Signal from the TNC

70
10
DATA COMMUNICATION
D Adjusting the transmit signal from the TNC
NOTE: For packet operation the transceiver can be
set to one of two data speeds: 1200 bps or 9600
bps. Data speed is set in initial set mode (item “36
9600 MODE”; see p.81).
q Push [POWER] for 1 sec. to turn power OFF.
w While pushing [LOCK], push [POWER] to turn
power ON.
• Initial set mode is selected and one of its items ap-
pears.
e Push [MENU] one or more times to select the item
“36 9600 MODE.”
• [M-CH] or [Y]/[Z] can also be used.
r Rotate the main dial to select the data speeds:
1200 bps or 9600 bps.
t To exit initial set mode, push [POWER] for 1 sec.
to turn power OFF.
y Push [POWER] to turn power ON again.
•The conditions selected in initial set mode are now ef-
fective.
When setting data transmission speed to 9600 bps,
the
DATA signal coming from the TNC is applied ex-
clusively to the internal limiter circuitry to automati-
cally maintain bandwidth.
NEVER apply data levels from the TNC of over 0.6
Vp-p, otherwise the transceiver will not be able to
maintain the band width and may possibly interfere
with other stations.
NOTE: Read the instructions supplied with your
TNC carefully before attempting packet operation
with the IC-703.
1.When using a level meter or synchroscope, adjust
the TX audio level (
DATA IN level) from the TNC as
follows.
0.4 Vp-p (0.2 Vrms): recommended level
0.2 Vp-p–0.5 Vp-p (0.1 Vrms–0.25 Vrms):
acceptable level
2.When not using a measuring device.
q Connect the IC-703 to a TNC.
w Enter a test mode (“CAL”, etc.) on the TNC, then
transmit some test data.
e When the transceiver fails to transmit test data or
transmits sporadically (TX indicator doesn’t appear
or flashes):
Decrease the TNC output level until the transmit
indicator lights continuously.
When transmission is not successful even though
the TX indicator lights continuously:
Increase the TNC output level.
Main dial[LOCK][MENU]
[MODE] Main dial[POWER]
[Y]
[Z]
10