CALAMP WIRELESS NETWORKS INC. BDD4T881S2 Manual De Usuario
120 20190-001
Paragon-III Technical Manual
30
5.2.3.2 Synthesizer
Alignment
Single channel: Connect the Multimeter to either side of L309 (T881) or the long lead of L1 in the
VCO (T857) (this measures the synthesizer loop voltage).
1. T881 (800 MHz) Tune VCO trimmer CV300 for a synthesizer loop voltage of 10V DC.
2. T857 (UHF) Tune VCO trimmer C6 for a synthesizer loop voltage of 10V DC.
Multiple channels (adjusting as shown for single channel above):
1. T881 (800 MHz) Adjust the VCO loop to 10V using the middle frequency channel.
2. T857 (UHF) Adjust the VCO loop to 10V using the middle frequency channel.
All channels should lie within the upper and lower limits of 16V and 3V respectively for the
T881 and T857 or within 13V.
T881 and T857 or within 13V.
Note:
Normally, the fast TX key option is installed and the synthesizer is always ener-
gized. In the case where that option was not fitted, key the transmitter by pressing
the front panel Carrier button to make the above adjustment possible.
gized. In the case where that option was not fitted, key the transmitter by pressing
the front panel Carrier button to make the above adjustment possible.
5.2.3.3
TX Frequency Error Adjustment
1. Apply the following settings to the IFR:
-
Receiver mode
-
IFR RX frequency to match the main radio TX frequency
-
IF Filter set to 30KHz
-
Zoom the RF Error window: select 10Khz range
2. Key the transmitter by pressing the front panel TX-Key button and measure the carrier output
frequency. It should be within ±300 Hz. If it is not, adjust the TCXO (IC700) to trim to meet the
requirement, preferably within 100Hz.
requirement, preferably within 100Hz.