Standard Test Conditions; Vco Alignment; Tcxo Calibration - RF Technology Eclipse Series Operation And Maintenance Manual

6.1 Standard Test Condition
TCXO calibration may be periodically required owing to normal quartz crystal aging. A drift
of 1ppm/year is to be expected.
Each alignment phase assumes that the preceding phase has been successfully carried out, or
at least that the module is already in properly aligned state with respect to preceding
conditions.
6.1 Standar d Test Condition
The following equipment and conditions are assumed unless stated otherwise:
• AF signal generator with 600Ω impedance, 50-3000Hz frequency range, with level set to
387mV RMS.
• Power supply set to 13.8Vdc, with a current capable of >5A.
• RF 50Ω load, 30W rated, return loss <-20dB.
• Jumpers set to factory default positions.
Model
T800A
T800B
T800C
6.2

VCO Alignment

1. Select a channel at the center frequency (half way between the highest and lowest
frequencies for the model in question).
2. Disconnect the Audio input (no signal input).
3. Key the PTT line.
4. Measure the voltage between pins 9 and 1 of the test socket (TUNE V), and adjust C99 to
obtain 4.5±0.25V, while the TX LED is ON and the ALARM LED is OFF.
6.3 TCXO Calibr ation
1. Select a channel at the center frequency (half way between the highest and lowest
frequencies for the model in question).
2. Disconnect the Audio input (no signal input).
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RF Technology T800
6 FIELD ALIGNMENT PROCEDURE
Alignment Frequency
Range
806-830
850-870
928-942
Align F
818MHz
860MHz
935MHz
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