Tait TM9100 Service Manual

316 Transmitter Fault Finding (25W Radios) TM9100 Service Manual
© Tait Electronics Limited August 2005
Frequency Bands
Some fault-diagnosis tasks require programming the radio with the lowest,
center or highest frequency in the radio’s frequency band. The relevant
frequencies for the different bands are listed in Table 12.2. Note that the
following frequency ranges are reserved worldwide for use by distress
beacons:
■ B1 band: 156.8MHz ± 375kHz
■ H5 band: 406.0 to 406.1MHz
Do not
program the radio with any frequency in the above ranges.
Can Removal There are five cans shielding the bulk of the transmitter circuitry:
■ PAD TOP
■ PAF TOP
■ DIRC TOP
■ PIN TOP
■ LPF TOP
To remove any can, first remove the main-board assembly from the chassis.
In the case of the
PAD TOP and PAF TOP cans, first detach the heat-transfer
block from the main board. Secure the block again after removing the cans.
Follow the procedures given in “Disassembly and Reassembly” on
page 123.
Can Replacement Replace all cans that have been removed only after repairing the board.
This applies to the B1, H5 and H6 bands. For certain other bands the
transmitter will not operate correctly unless all the cans are fitted.
Table 12.2 Lowest, center and highest frequencies in MHz
Band
Lowest
frequency
Center
frequency
Highest
frequency
B1
H5
H6
136
400
450
155
435
490
174
470
530

Tait TM9100 Specifications

General

Brand	Tait
Model	TM9100
Category	Radio
Language	English