AlimentProcedure

FCC ID: CKEJHS-500

Parts List/Tune Up Info

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FCCID_125343

                   VHF/FM RADIO TELEPHONE            JHS-500

                       Alignment    Procedure

This section describes the alignment procedure for the radio.
Please refer to the alignment location diagram.


1. Test Equipment:


The following test equipment is recommended for radio alignment.


* Communication Monitor (HP8920B or equivalent)
* DC Voltmeter (>1 megohms input impedance)
* DC Power Supply ( 10 to 20 volts at 10 amp)
* RF Coaxial Cable
* Power Cable


2. Initial Setup


NOTE:
> Connect DC power cable to radio and set voltage on power supply for 13.8 volts.
> Connect radio to Communication Monitor.
> Turn on radio and note 16 channel on LCD segments light.


VCO
> Set the power supply voltage to 13.8 V
> Select radio channel 16
> Use high impedance prove to measure the VCO control voltage at TP1
> Align the trimmer capacitor C317 for RX
            VCO control voltage : 1.6V
> Key the radio under low power mode
> Align the trimmer capacitor C318 for TX
            VCO control voltage : 1.8V




                                           1


Reference OSC
> Set the power supply voltage to 13.8V
> Select radio channel 16 and key the radio under low power mode
> Align the trimmer capacitor C337 to obtain 156.800+/-100Hz at the room
   temperature


RF Output Power
> Set the power supply voltage to 13.8V
> Select radio channel 16 and key the radio under low power mode
> Align VR201 to obtain 0.9W RF output power
> Set the radio for high power mode
> Align VR202 to obtain 24W RF output power


Transmitter Modulation
> Set the power supply voltage to 13.8V
> Select radio channel 16 and key the radio under low power mode
> Apply a 1KHz tone at 140 mV input level to the transmitter audio input (J503)
> Adjust modulation control VR401 to obtain the maximum deviation 4.5KHz
          Note:
          HP8920B : <20Hz HPF,15k LPF, De-emph. off,Peak +/-Max


RX Tone Decoder
> Set the power supply voltage to 13.8V
> Press “WX” key and select radio channel WX1
> Provide RF signal : 162.550 MHz, -113dBm modulated with 1050Hz tone at the
  standard deviation (3.0 kHz)
> Rotate the volume control VR503 and note the location that “ALT” flashes on
  the LCD display
> Rotate further the VR501 and note the location that “ALT” turned off
  Set the VR503 between them




                                          2


1. RF PCB Alignment Location




       VR401        C337       TP1       C317     C318   VR201   VR202



2. LOGIC PCB Alignment Location




     VR501                 VR502          VR503



                                     3


PC Board VIEW

1)   RF Unit Side A




2)   RF Unit Side B




                      4


3)   LOGIC Unit Side A




4)   LOGIC Unit Side B




                          U501
                         NJM2211M




                                    5



Document Created: 2000-11-07 18:14:56
Document Modified: 2000-11-07 18:14:56

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