Alignments
RCI 2950, 2970, & 2990 ALIGNMENT PROCEDURE
1.0 INTRODUCTION
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
1.1 Connect digital voltmeter to jumper J13. Adjust L17 for a reading of 2.2 VDC ±0.1 volts
1.2 Connect digital voltmeter to pin 3 of IC7. Adjust L21 to 1.2 VDC ±0.1
1.3 Connect a frequency counter to L61 and adjust VC1 for a reading of 10.240 MHz ±10Hz
1.4 Connect a 50 ohm dummy load to the antenna connector
1.5 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.
1.6 Connect a frequency counter to
the cathode of D45. Put mode selector on AM. Key the transmitter and adjust L27 for
10.6950 MHz ± 10Hz.
1.7 Adjust VR7 fully clockwise. Leave the frequency counter connected to D45. Put the mode selector on USB. Key the transmitter and adjust L29 for 10.6925 MHz ± 10 Hz.
1.8 Put the mode selector in
LSB. Key the transmitter and adjust L28 to 10.6975 MHz ± 10Hz. Return VR7 to
approximately the middle of rotation.
1.9 Put the mode selector in AM. Connect X10 probe to pin 13, IC17 Check the frequency counter for 5.930 MHz.
1.10 Set the oscilloscope for 50nS
(.05µS) per division on the vertical input. Connect X10 probe to IC17 pin 13 and
very
carefully adjust L24 and L25 for the best waveform.
RECEIVER ALIGNMENT
2.1 Put the mode selector in FM, the RF gain fully clockwise, Clarifier at 12 o'clock and the frequency at 28.0300 MHz
2.2 Connect an FM signal generator to the antenna connector. Set the modulation for ±3 kHz, output level at 0.5µV.
2.3 Connect a SINAD meter to the external speaker jack, adjust volume to approximately 10 o'clock.
2.4 Connect X10 probe to the
cathode of D12. Set oscilloscope sweep selector for 1ms per division and vertical
input
selector for 10mv per division.
2.5 Adjust L8 for the best SINAD
reading and the least distortion wave form on the scope. Do not try tuning this coil
for
the maximum, as this will result in degraded performance.
2.6 Adjust
L9,L11,L12,L13,L14,L4,L3,L5 and L6 for maximum on scope. Reduce generator if
necessary, so as not to
exceed vertical height on scope.
2.7 Adjust L6 and L5 for best SINAD
2.8 Put mode selector on LSB.
Signal generator to 28.0290 MHz, modulation of output level at 0.5µV. Tune L15 and
L16 for maximum waveform on scope.
TRANSMITTER ALIGNMENT
RCI-2970 LEVELS ARE SHOWN IN [ ]
3.1 Connect an audio generator to
pin 2 and ground (pin 1) of the Mic connector. The Mic gain should be fully
counterclockwise. Set generator for 30mV RMS., 1 kHz
sinewave
3.2 Adjust VR14 fully counterclockwise
3.3 Adjust VR12 fully counterclockwise.
3.4 Connect a wattmeter and 50 ohm dummy load to the antenna connector. Set the wattmeter for 30W scales [100W]
3.5 Key the transmitter and slowly
increase the Mic gain until you obtain approximately 10W. Adjust L19, L48, L47
and
L43 for maximum reading on the wattmeter. Reduce Mic gain if
necessary to maintain about 10 to 15W on wattmeter
[40-50W].
3.6 Increase the Mic gain to maximum
(fully clockwise). Key transmitter and adjust L34 for maximum power output.
Power will typically be 30-35W [100-120W].
3.7 With the Mic gain still maximum of LSB, key the transmitter and adjust VR12 for 25W [100W].
3.8 Put the mode selector on AM. Key the transmitter with no modulation applied and adjust VR13 for 10W [50W].
3.9 With the mode selector still on
AM, re-connect 1 kHz audio the generator to radio and key transmitter. With Mic gain
at
maximum, adjust VR14 for 90% modulation. Use the mod
meter or oscilloscope with RF sampler [85%].
3.10 Put the 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 transmit audio. Use the deviation meter or the
service monitor.