Radio Modification Information

HR2600 Alignment Instructions - (Taken from the Uniden Service Manual)

Alignment of P.L.L. and Carrier Oscillator Portion

1. Test equipment required:

     DC Power supply (13.8V)                 Oscilloscope
     DC Voltmeter                                      Frequency Counter
     Dummy Load (50 Ohm)

2. Preparation for Alignment:

     RIT SW : Off                                         Mode SW : AM
     RIT : Middle Position                          TX SW : Off
                                          Remove the PCB (B 751, PB-100) from the Main PCB.

3. Alignment Procedure:

	Preset to:	Adjustment	Remarks
1	Mode : RX, AM SG : 28MHz	L315	Connect an oscilloscope to TP306. Adjust L315 For 6.200MHz +/- reading on the oscilloscope.
2	Ditto	L318	Connect the oscilloscpe to TP304. Adjust L318 for 38.695MHz +/- 20Hz reading on the oscilloscope.
3	Mode : RX, AM SG : 29.6999 MHz	L317	Connect a DC Voltmeter to TP303. Adjust L317 for 5.5 +/- 0.1V reading on the Dc Voltmeter.
4	Mode : RX, CW SG : 28 MHz	L8	Connect the oscilloscope to TP2 (R61). Adjust L8 for 10.6950MHz +/- 20Hz reading on the oscilloscope.
5	Mode : RX, LSB	L9	Adjust L9 for 10.6925MHz reading on the oscilloscope.
6	Mode : RX, USB	L10	Adjust L10 for 10.6975MHz +/- 20 Hz reading on the oscilloscope.
7	Mode : RX, USB	VR11	Connect the oscilloscope to TP1 (R7). Adjust VR11 for 38.6925MHz +/- 20 Hz reading on the oscilloscope

Click Here to see Alignment layout

Alignment of Transmitter Portion

1. Test equipment required:

     DC Power supply (13.8V) more than 10A
    AF S.S.G. AM FM (1kHz, 500Hz and 2400Hz)
    RF VTVM                                      Oscilloscope
    DC Ammeter                                RF Power Meter
    AF VTVM                                      Dummy Load (50 Ohm)
    FM Linear Detector

2. Preparation for Alignment:

     VR13 : Clockwise                       RIT SW         : Off
     VR14 : Counter Clockwise        Meter SW     : RF
     VR4   : Clockwise                       MicGain SW : Off
     SWR/CAL : Middle Position      TX SW          : Off
     Freq. : 29.000 MHz

3. Alignment Procedure:

Preset to: Adjustment Remarks

1 Mode:USB
No Mod. VR13
Remove the B751(PB-100) from the Main PCB.
Connect a DC Ammeter (+) to TP4, (-) to TP3.
Adjust VR13 for 50mA reading on the DC Ammeter.

2 Ditto VR14 Connect a DC Ammeter (+) to TP4, (-) to TP2.
Adjust VR14 for 50 mA reading on DC Ammeter.

3 1mV Mod. L25 Disconnect DC Ammeter. Reinstall the B751 to the Main PCB.
Connect A RF Power meter to the ANT. jack. Connect a RF VTVM, an oscilloscope and a FM Linear Detector across a RF Dummy Load to the RF Power meter.
Adjust L25 for maximum reading on the RF VTVM.
During this step, set the AF oscillator so that the output is less than 20V.

4 30 mV Mod. VR5 Adjust VR5 for 32.5V reading on the RF VTVM.

5 Ditto VR7 Adjust VR7 so that the carrier leakage at USB and LSB becomes minimum and almost equal.

6 Mode: CW
No Mod. VR4 Connect a SW between Pin 8 and 9 of the ACC connector.
With the SW turned on, adjust VR4 for 34.5V reading on the RF VTVM.

7 Mode: AM
No Mod. VR8 Adjust VR8 for 10W reading on the RF power meter.

8 Ditto VR12 Adjust VR12 so that "9" LCD just lights on.

9 1 kHz, 30mV
Modulation VR6 Adjust VR6 to obtain the 80% negative reading on the oscilloscope.

10 1kHz, 1mV
Modulation
INDIC: MOD VR9 Adjust VR9 so that "9" LCD just lights on.

11 Mode: FM
1kHz, 30mV
Modulation VR3 Adjust VR3 for +/- 4kHz deviation reading on the FM Linear Detector

12 FM No Mod
RPT SW: ON VR303 Adjust VR303 for +/- 0.6khz deviation reading on the FM Linear Detector.

13 Mode: CW
No Mod.
Vol. : Max VR10 Connect a AF VTVM across a dummy load (8 Ohm) between Pin 1 and Pin 2 of the ACC connector. With the SW turned on, adjust VR116 for 0.4V negative reading on the AF VTVM.

Click Here to see Alignment layout

Alignment of Receiver Portion

1. Test equipment required:

     AF VTVM                                     DC Power supply (13.8V)
     Oscilloscope                                Dummy Load (50 Ohm)
     S.S.G. (29.000MHz, 1KHz, 30% Mod. 1kHz 1.5kHz Dev.and 50 Ohm Impedance)

2. Preparation for Alignment:

     NB SW     : Off                               Mode     : AM
     RIT SW     : Off                               Squelch : Min. (Auto SQ Off)
     RPT SW   : Off                               RF Gain : MAX
     VOLUME : MAX                           TX SW   : Off
     RIT            : Middle position

3. Alignment Procedure:

     Preset to: Adjustment                                                        Remarks

1 RX 29MHz
1kHz,30% Mod L1 ~ L6                                 Alignment of sensitivity
Adjust coils for maximum reading of the AF VTVM. (During this step, set the S.S.G. attenuator so that the standard output is less than 0.5W (2v/8ohm)).

2 Ditto     VR2                                Alignment of Squelch
Set the output of the S.S.G. to 66dB +/- 2dB and squelch to maximum. Adjust VR2 so that squelch just breaks.

3 No Mod.
Meter : RF     VR1                                Alignment of S-Meter
Set the output of the S.S.G. to 46dB, no modulation.
Adjust VR101 so that "9" LCD just lights on.

Click Here to see Alignment layout

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