Alinco DR-635 - Manual (Page 61)

59
Maintenance / Reference
Problem
Packet
communication does
not function.
APRS does not
function.
Possible Causes
a. TNC is not connected or set
properly.
b. The unit is not in the packet
mode.
c. The squelch is open.
d. The data transmission speed
is not configured.
e. A PC cable other than the
straight type is used.
a. The unit is not in the packet
mode.
b. The unit is not configured for
automatic transmission.
c. The squelch is open.
d. The GPS receiver is not
geolocating.
Potential Solutions
a. Make sure the connections and
configurations are properly set.
b. Switch to the packet mode.
c. Adjust the squelch level where it
will open by reception of a signal.
d. Adjust the speed by the PC.
e. Use a straight type PC cable.
a. Switch to the packet mode.
b. Use the PC to set transmission
time separation.
c. Adjust the squelch level where it
will open by a reception signal.
d. Wait until the GPS receiver
properly geolocates.
IMPORTANT: When reception frequencies fall in any one of the formulas below, the unit may
receive a non-modulated signal.
This is due to the structure of frequencies of this unit and not a malfunction of the
unit.
• (Reception frequency on the MAIN side - 45.1MHz )
= Reception frequency on the SUB side - 43.4MHz (In u-u)
• (FM reception frequency + 10.7MHz) x 4 = UHF reception frequency - 90.2MHz
• (FM reception frequency + 10.7MHz) x 5 = UHF reception frequency
• (UHF reception frequency - 45.1MHz) x 2
- (VHF reception frequency - 21.7MHz) x 6 = 45.1MHz
• (UHF reception frequency - 45.1MHz) - (VHF reception frequency - 21.7MHz) x 3
= 21.7MHz
• In case you are monitoring the 3 multiple of TX frequency, you may hear your
voice from the unit but this is normal.
• EMS-57 DTMF equipped microphone
(This comes standard with the DR-635T)
• EJ-50U TNC unit
Optional accessories
• EMS-53 Microphone
(This comes standard with the DR-635E)