Alignment Procedures
RCI-2950 - 2970 - 2990
( Note: For DX Series, see DX Series )
PLL Synthesizer / Oscillator Frequency Alignment - Receiver Alignment
2950 Transmitter Alignment - 2970-2990 Transmitter Alignment
Equipment required for Alignment procedure:
• DC Power Supply ( 13.8 Vdc, 20A )
• Oscilloscope (50 MHz), with X10 probe
• 50 W dummy load
• Frequency Counter - 0 to 30 MHz
• Digital voltmeter or Multimeter.
• Audio Generator
• FM Signal Generator
• SINAD Meter
• RF Wattmetter ( 25~60 MHz, 100W )
Internal Alignment Points:
VR1
VR2
VR3
VR4
VR7
VR8
VR11
VR12
VR13
VR14
VR15
VR16
VR21
AM Receive Meter CAL
SSB Receive Meter CAL
SSB Squelch Threshold
AM Squelch Threshold
Carrier Balance
Transmit Meter CAL
Driver Bias
ALC ( SSB High Power )
AM Carrier ( High Power )
AMC
AM Carrier ( Low Power )
ALC ( SSB Low Power )
TX Frequency Adjustment
VC1
VC2
L27
L28
L29
10.240 Crystal Trimmer ( X1 )
10.240 Crystal Trimmer ( X2 )
AM Frequency Adjustment
LSB Frequency Adjustment
USB Frequency Adjustment
To view Main PCB Adjustment for location of adjustment points, please see this drawing - 2950 Main PCB. After viewing, press "back" to return to this page.
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The following steps are required to re-align the RCI-2950-2970.
Caution: Alignment should only be attempted by personnel trained in RF product testing and alignment.
PLL Synthesizer / Oscillator Frequency Alignment:
1. Set radio controls as follows:
Frequency:
Mic Gain:
RF Power:
RF Gain:
Clarifier:
Volume On/Off:
Squelch:
Mode Selector:
28.0000 Mhz
Fully counter clockwise
Fully clockwise
Fully clockwise
12 o'clock
On
Fully counter clockwise
FM
2. Connect a digital voltmeter to jumper J13. Adjust L17 for a reading of 2.2 Vdc ± 0.1
3. Connect a digital voltmeter to pin 3 if IC7. Adjust L21 for a reading of 1.2 Vdc ± 0.1
4. Connect a frequency counter to L61. Adjust VC1 for 10.240 MHz ± 10 Hz
5. Connect a 50 W dummy load to the antenna connector.
6. Connect a frequency counter to pin 3 of IC14. Ensure that the clarifier is precisely at the 12 o'clock position. Adjust VC2 for 10.240 MHz (± 10 Hz). Key the transmitter and adjust VR21 for 10.240 MHz (± 10 Hz).
7. Connect a frequency counter to the cathode of D45. Put mode selector on AM. Key the transmitter and adjust L27 for 10.6950 MHz (± 10 Hz).
8. Adjust VR7 fully clockwise. Leave the frequency counter connected to D45. Put the mode selector on USB. Key the transmitter and adjust L29 for 10.6950 MHz (± 10 Hz).
9. Put the mode selector in LSB. Key the transmitter and adjust L28 for 10.6975 MHz (± 10 Hz). Return VR7 to approximately the middle of rotation.
10. Put the mode selector in AM. Connect X10 probe to pin 13, IC17. Check the frequency counter for 5.930 MHz.
11. Set the oscilloscope for 50ns (.05µS) per division on the sweep selector and 10mV per division on the vertical input. Connect X10 probe to IC17 pin 13 and very carefully adjust L24 and L25 for the best waveform.
This completes this stage of the alignment procedure.
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Receiver Alignment:
1. Put the mode selector on FM, the RF gain fully clockwise, Clarifier at 12 o'clock,and the Frequency at 28.0300 MHz.
2. Connect an FM signal generator to the antenna connector. Set the modulation for ± 3 KHz, output level to 0.5 µV.
3. Connect a SINAD meter to the external speaker jack, adjust the volume control to approximately 10 o'clock.
4. Connect an X10 probe to the cathode of D12. Set oscilloscope sweep selector for 1mS per division and vertical input selector for 10mV per division.
5. Adjust L8 for the best SINAD reading and the least distorted wave form on the Scope. Do not try tuning this coil for the maximum, as this will result in degraded receiver performance.
6. Adjust L9, L11, L12, L13, L14, L4, L3, L5, and L6 for maximum on scope. Reduce generator level if necessary, so as not to exceed vertical height on scope.
7. Adjust L6 and L5 for best SINAD.
8. Put the mode selector on LSB, signal generator to 28.0290 MHz, modulation off, output level at 0.5 µV. Tune L15 and L16 for maximum waveform on scope.
This completes the Receiver stage of the alignment procedure.
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2950 Transmitter Alignment:
1.Connect an audio generator to pin 2 and ground (pin 1) of the Mic connector. The Mic gain should be fully counterclockwise. Set generator 30mV RMS, 1KHz sinewave. Set mode selector to LSB.
2. Adjust VR14 fully counterclockwise.
3. Adjust VR12 fully counterclockwise.
4. Connect a wattmeter and a 50 W dummy load to the antenna connector. Set the wattmeter for 30W scales.
5. Key the transmitter and slowly increase the Mic gain until you obtain approximately 10W. Adjust L19, L48, L47, L46 and L43 for maximum reading on the wattmeter. Reduce Mic gain if necessary to maintain about 10 to 15W on the meter.
6. Increase the Mic gain to maximum (fully clockwise). Key transmitter and adjust L34 for maximum power output. Power will typically be 30-35W.
7. With the Mic gain still maximum on LSB, Key the transmitter and adjust VR12 for 25W.
8. Put the mode selector on AM. Key the transmitter with no modulation applied and adjust VR13 for 10W.
9. With the mode selector still on AM, re-connect 1 KHz audio generator to radio and adjust VR14 for 90% modulation. Use the modulation meter or oscilloscope with RF sampler.
10. Put mode selector on FM. Key the transmitter and check for 4 KHz deviation ± 0.5 KHz. There is no deviation adjustment provided in this radio. Simply check for sufficient transmitt audio. Usse the deviation meter or the service monitor.
This completes the 2950 Transmitter stage of the alignment procedure.
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2970-2990 Transmitter Alignment:
1.Connect an audio generator to pin 2 and ground (pin 1) of the Mic connector. The Mic gain should be fully counterclockwise. Set generator 30mV RMS, 1KHz sinewave.
2. Adjust VR14 fully counterclockwise.
3. Adjust VR12 fully counterclockwise.
4. Connect a watt meter and a 50 W dummy load to the antenna connector. Set the wattmeter for 100W scales.
5. Key the transmitter and slowly increase the Mic gain until you obtain approximately 10W. Adjust L19, L48, L47, L46 and L43 for maximum reading on the watt meter. Reduce Mic gain if necessary to maintain about 40 to 50W on the meter.
6. Increase the Mic gain to maximum (fully clockwise). Key transmitter and adjust L34 for maximum power output. Power will typically be 100-200W.
7. With the Mic gain still maximum on LSB, Key the transmitter and adjust VR12 for 100W.
8. Put the mode selector on AM. Key the transmitter with no modulation applied and adjust VR13 for 50W.
9. With the mode selector still on AM, re-connect 1 KHz audio generator to radio and adjust VR14 for 85% modulation. Use the modulation meter or oscilloscope with RF sampler.
10. Put mode selector on FM. Key the transmitter and check for 4 KHz deviation ± 0.5 KHz. There is no deviation adjustment provided in this radio. Simply check for sufficient transmitt audio. Use the deviation meter or the service monitor.
This completes the 2970 Transmitter stage of the alignment procedure.
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Ranger Communications, Inc.
401 W. 35th Street
National City, CA 91950
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