TTI TCB-880 - Transmitter Section Alignment

5-2 Transmitter Section
5-2-1 Test Equipment Required
• RF Power Meter • DC power supply(13.8V/3A)
• 50 ohms load (non-inductive) • Spectrum analyzer
• RF attenuator (30dB) • Frequency counter
• Oscilloscope • Coupler
• Audio generator • Modulation meter
5-2-2 Alignment Procedure
Step Setting Connection Adjuster Adjust for
1
RF Power Adj.
Channel : 19CH
Function : AM or FM Mode
CB/ANL Off/DX
MIC : Transmit
Volume : Optional
Squelch : Optional
RF Gain : Optional
MIC Gain : Minimum
Connect dummy load and RF
Power Meter to the EXT–ANT
connector on the set(Figure 3)
L302
L701
L702
L703
Maximum
indication on
the Power
Meter(4.0W).
If indication is
not in 4W
range, ACP
Adjustment(R
V911)
2 Frequency Adj.
Channel & Frequency :
19CH, 26.956 MHz
Function : AM or FM Mode
CB/ANL Off/DX
Mic : Transmit(No Mod)
Volume : Optional
Squelch : Optional
RF Gain : Optional
MIC Gain : Optional
Connect dummy load and
Frequency Counter through
Coupler to RF Power Meter.
Connect RF Power Meter to
EXT-ANT connector on the
set(Figure 2).
CT302 Be sure that
the indication
of the
transmitter
frequency is
27.185MHz
±300 Hz on
the Frequency
Counter
3
AM Modulation Adj.
Channel & Frequency :
19CH, 27.185MHz
MIC: Transmit
Function : AM Mode
CB/ANL Off/DX
Volume : Optional
Squelch : Optional
RF Gain : Optional
MIC Gain : Max
Connection the audio
generator (set to 1 KHz)to the
microphone.
Connect the modulation meter
through the RF attenuator to
the ANT Connector. Adjust
the audio signal level to obtain
by 50% modulation.
When you increase the audio
signal by 20 dB, the
modulation should not exceed
95% Modulation(Figure 3).
RV231 85% ~ 95%