MDS 05-2415A01, Rev. A 6-1
CHAPTER 6—TROUBLESHOOTING
If difficulties are experienced with the radio system, the steps outlined below can help isolate
the faulty component. For specific instructions on performing the tests or adjustments rec-
ommended in this chapter, refer to Chapter 4—Field Tests and Adjustments. For instructions
on using the Hand-Held Terminal (HHT), refer to Chapter 3—Programming and
Diagnostics.
Troubleshooting assistance is also available from Microwave Data Systems in Rochester, NY
(Telephone No. (716) 242-9600). Please have the complete model number and serial number
of the transceiver ready when calling for assistance. Refer to the inside back cover of this
manual for more information on obtaining factory assistance.
UNIT DOES NOT TRANSMIT OR RECEIVE
1. Power Supply Evaluation
a. Check for + 13.8 Vdc at transceiver’s primary power connector.
b. Check the in-line fuse in the power cable assembly; if defective, replace with
type 3AG, 3 A fuse.
c. Check for continuity of plug-in fuse F1 (4A/Fast Blo) on the transceiver
motherboard. If it is blown, check for reverse polarity or excessive voltage on
primary power leads. When the problem has been corrected, replace the fuse.
2. Antenna System Evaluation
a. Check antenna feedline and connections. VSWR should be no higher than 1.5:1.
Higher VSWR values usually will not prevent the radio from functioning, but
may degrade system performance.
3. Operating Frequencies Review
a. Check the transmit/receive frequencies and other radio operating parameters
using HHT or PC terminal.
UNIT RECEIVES, BUT DOES NOT TRANSMIT
1. PTT Circuit Evaluation
a. Check keying signal being supplied by RTU. Measure keyline input at DB-25
INTERFACE connector; either Pin 14 or 16 of this connector should be activated.
Alternate—Pin 4 of the INTERFACE connector.
b. Apply + 5 Vdc to Pin 14 (PTT), of the DB-25 INTERFACE connector, or a ground
to Pin 16
PTT of the DB-25 connector. The transceiver should key.
c. On modem-equipped radios, check the DB-25
INTERFACE connector for proper
RTS (Pin 4) and CTS (Pin 5) signals.
d. Key transmitter with HHT using the KEY command.
Continued on next page.
To Next Page
Loading...