Ranger Communications (Shanghi) Inc.
Model No: VX-129CN VIRAGE NIGHT TALKER
SOLID STATE 40 CHANNEL AM MOBILE CB RADIO
The VX-129CN is a double sideband, amplitude modulated, transmitter/receiver combination intended for mobile operation in the citizens radio service. The transmitter has 40-channel capability in the 26.965 - 27.405 MHz band utilizing phase locked loop (PLL) technology.
CIRCUITS AMD DEVICES TO STABILIZE FREQUENCY
All 40 channels of transmitting, and receiving, frequencies are provided by PLL (Phase Locked Loop)(IC 2, MB8719) circuitry.
The purpose of the PLL is to provide a multiple number of frequencies from a VCO (Voltage Controlled Oscillator) with quartz crystal accuracy and stability locked to crystal oscillator reference frequency.
The reference crystal oscillator frequency is 10.240 MHz.
1. Circuits For Suppression Of Spurious Radiation
The tuning circuit between frequency synthesizer and final amp and "PI" network L11, L12, L13, L14, C56, C57, C58, C59 in the output circuit serve to suppress spurious radiation. This network serves to impedance match final rf amplifier to the antenna and to reduce spurious content to acceptable levels in the frequency synthesizer.
2. Circuits For Limiting Modulation
A very effective ALC (Automatic Level Control) circuit is used to limit audio gain so as not to over modulate beyond 90%. The dynamic range of the AKC circuit for this purpose is over 50 dB.
The output audio level is sensed and applied to IC1 mike amp/limiter to provide mike gain inversely proportional to rf output.
To eliminate modulation percentage variation due to power supply voltage change a supply voltage sensor circuit is incorporated into the ALC system.
- Model VX-129CN
- Channels 40
- Frequency Range 26.965 ~ 27.405 MHz
- Emission AM
- Frequency Control Phase-Lock-loop (PLL) Synthesizer
- Frequency Stability 0.001%
- Temperature Range -30°C to +50°C
- Antenna Impedance 50 Ohms
- Antenna Connectors Standard SO-239 type
- Input Voltage 13.8V DC
- Size 7 7/8" (W) x 9 1/4" (D) x 2 3/8" (H)
- Weight 5.0 lbs.
- RF Power Output AM : 4W
- Spurious Emission -55 dB
- Audio Distortion 10%
- Frequency Response 300 to 2500 Hz
- Microphone Dynamic
- Sensitivity for 10 dB (S+N)/N < 1.0 uV (AM)
- Squelch Sensitivity < 0.5 uV
- Image Rejection More than 65 dB
- AGC Figure of Merit 100 mV for 10dB Change in Audio Output
- Audio Power Output 2.5W @ 10% Distortion
- Audio Response 300 to 2500 Hz
ALTERNATE MICROPHONES AND INSTALLATION
For best results, the user should select a low-impedance dynamic type microphone or a transistorized microphone. Transistorized type microphones have low output impedance characteristics. The microphones must be provided with a four-lead cable. The audio conductor and its shielded lead comprise two of the leads. The third lead is for transmit control and fourth is for receiving control.
The microphone should provide the functions shown in schematic below.
If the microphone to be used is provided with precut leads, they must be revised as follows.
1. Cut leads so that they extend 7/16" beyond the plastic insulating jacket of the microphone cable.
2. All leads should be cut to the same length. Strip the ends of each wire 1/8" and tin the exposed wire.
Before beginning the actual wiring, read carefully the circuit and wiring information provided with the microphone you select. Use the minimum heat required in soldering the connections. Keep the exposed wire lengths to a minimum to avoid shorting when the microphone plug is reassembled.
To wire the microphone cable to the plug provided, proceed as follows :
1. Remove the retaining screw.
2. Unscrew the housing from the pin receptacle body.
3. Loosen the two cable clamp retainer screws.
4. Feed the microphone cable through the housing, knurled ring and washer as shown Figure 2.
5. The wires must now be soldered to the pins as indicated in the above wiring tables. If a vise or clamping tool is available it should be used to hold the pin receptacle body during the soldering operation, so that both hands are free to perform the soldering. If a vise or clamping tool is not available, the pin receptacle body can be held in a stationary position by inserting it into the microphone jack on the front panel. The numbers of the microphone plug are shown in Fig. 3, as viewed from the back of the plug. Before soldering the wire to the pins, pre-tin the wire receptacle of each pin of the plug.
6. Be sure that the housing and the knurled ring of Figure 2 are pushed back onto the microphone cable before starting to solder. If the washer is not captive to the pin receptacle body, make sure that it is placed on the threaded portion of the pin receptacle body before soldering.
7. If the microphone jack is used to hold the pin receptacle during soldering operation, best results are obtained when the connections to pin 1 and 3 are made first and then the connections to pins 2 and 4. Use a minimum amount of soldering and be careful to prevent excessive solder accumulation on pins, which could cause a short between the pin and the microphone plug housing.
8. When all soldering connections to the pins of the microphone are completed, push the knurled ring and the housing forward and screw the housing onto the threaded portion of the pin receptacle body. Note the location of the screw clearance hole in the plug housing with respect to the threaded hole in the pin receptacle body. When the housing is completely threaded into the pin receptacle body, a final fraction of a turn either clockwise or counterclockwise may be required to align the screw hole with the threaded hole in the pin receptacle body. When these are aligned, the retaining screw is then screwed into place to secure the housing to the pin receptacle body.
9. The two cable clamp retainer screws should now be tightened to secure the housing to the microphone cord. If the cutting directions have been carefully followed, the cable clamp should secure to the insulation jacket of the microphone cable.
10. Upon completion of the microphone plug wiring, connect and secure the microphone plug in the transceiver.
MAINTENANCE AND ADJUSTMENT
RANGER_VX-129CN Schematic Diagram.pdf