Specifications
4. The middle RX/TX frequencies should be halfway between the lowest and the highest frequencies.
• NOTE: There should be 4 channels programmed with a total of 3 different frequencies.
PLL ALIGNMENT
1. Connect an RF dummy load or power attenuator (50 watt minimum rating) to the antenna connector.
2. Connect a VOM or DVM to TP1, accessed through a hole in the VCO cover.
3. Set the CHANNEL selector to the highest transmit frequency.
4. Press the push-to-talk (PTT) switch. Adjust TC5 for a 7.0 VDC reading on the VOM. Release the PTT
switch.
5. Change the CHANNEL selector to the lowest transmit frequency.
6.
Press the PTT switch. The VOM should read 1.5 VDC ± 0.2V VDC. If not, re-adjust TC5 slightly for a 1.5
VDC reading. Release the PTT switch.
7. Return to the highest transmit channel and verify that the TP1 voltage does not exceed 8 volts in transmit.
On the lowest transmit frequency, the voltage must be 1.5 ± 0.2 VDC, and on the highest transmit
frequency, the voltage must be less than 7.5 VDC. Repeat steps 3 through 6 if necessary.
8. Set the CHANNEL selector to the lowest receive frequency.
9. Adjust TC3 to obtain a 2 VDC reading on the VOM.
10. Change the CHANNEL selector to the highest receive frequency. Verify that the DC voltage does not
exceed 7.0 VDC. If it does, re-adjust TC3 for a 7.0 VDC reading.
11. The following chart shows typical voltages at TP1:
CHANNEL
TP1 VOLTAGE
TRANSMIT RECEIVE
Lowest Frequency 1.5 VDC 2.0 VDC
Highest Frequency 7.5 VDC 7.0 VDC
TRANSMITTER
TRANSMITTER ALIGNMENT
1. Connect a 50 ohm RF dummy load or a power attenuator (50 watt minimum rating) through a watt meter
(50 watt scale) to the antenna connector.
2. Turn RV2 (Automatic Power Adjustment) fully clockwise.
3. Connect variable DC power supply (10 Ampere capability) to the DC power cable on the radio. Set the
voltage to 12 VDC measured at the radio during transmit. (Voltage drops in the power cable during transmit
will lower the voltage at the radio).
4. Set the CHANNEL selector to a mid-frequency transmit channel.
5. Press the PTT switch.
6. Adjust RV2 for 40 watts, or the desired power output (10 - 40 watts). Release the PTT switch.
MONOGRAM SERIES LBI-38864B
ALIGNMENT PROCEDURE
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Nov. 94