Operating instructions

RF Technology T350/T500 Page 17
6 FIELD ALIGNMENT PROCEDURE 6.1 Standard Test Condition
6.1 Standard Test Condition
The following equipment and conditions are assumed unless stated otherwise:
• AF signal generator with 600Ω impedance, 150-3000Hz 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.
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 Calibration
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 carrier frequency at the output connector, and adjust XO1 until the
correct carrier frequency is measured, ±50Hz.
6.4 Modulation Balance
1. Set RV3 fully counter clockwise (CCW) (sub-tone off).
2. Set RV1 fully clockwise (CW) (maximum deviation)
3. Set RV2 mid-position
4. Set JP7 for flat response
5. Key the transmitter on