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Test equipment required:
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Power Supply: 13,8 V |
AF SSG |
RF VTVM |
DC AM-meter |
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AF VTVM |
FM Linear Detector |
Oscilloscope |
RF Power Meter |
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Dummy Load, 50 ohm |
Preparation alignment:
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VR112 |
Clockwise |
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VR113 |
Counter Clockwise |
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VR103 |
Clockwise |
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SWR/CAL |
Clockwise |
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RF Gain |
Middle position |
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PA SW |
Off |
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INDIC SW |
RF |
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Mic Gain Sw |
Off |
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RF Power |
Max. |
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Frequency |
28.000 MHz |
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Step |
Condition |
Adjustment |
Procedure |
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1 |
USB |
VR13 |
Remove the B002 (PB-100) from Main PCB. Connect a DC AM Meter to TP4 (+) and TP3 (-). Adjust VR13 for 50 mA reading on the DC AM Meter. |
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2 |
USB |
VR14 |
Remove the B002 (PB-100) from Main PCB. Connect the DC AM Meter to TP4 (+) and TP2 (-). Adjust VR14 for 50 mA reading on the DC AM Meter |
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3 |
USB |
L25 |
Connect a RF Power Meter to Ant.jack. Connect a RF VTVM, an Oscilloscope and an RF Linear Dectector across an Dummy Load to the RF Power meter. Adjust L25 for maximum reading en the RF VTVM. During this step, set the AF Oscillator so that the output is less than 20 V. Repeat this step two times. |
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4 |
USB |
VR5 |
Adjust VR5 for 32.5 V reading on the RF VTVM. |
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5 |
USB |
VR7 |
Adjust VR7 so that the carrier leakage at USB and LSB become minimum and almost equal. |
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6 |
CW |
VR4 |
Connect a SW between Pin 8 and 9 of ACC connector. When turn on the SW, adjust VR4 for 21 Watt reading on the RF Power Meter. |
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7 |
AM |
VR8 |
Adjust VR8 for 10 Watt reading on the RF Power Meter |
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8 |
AM |
VR12 |
Adjust VR12 so that "9" LCD just light on. |
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9 |
AM |
VR6 |
Adjust VR6 to obtain the 85% negative reading on the Oscilloscope. |
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10 |
AM |
VR9 |
INDIC: MOD. Adjust VR9 so that "9" LCD just light on. |
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11 |
FM |
VR3 |
Adjust VR3 for +/- 3 kHz deviation on the FM Linear Detector. |
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12 |
CW |
VR10 |
Connect an AF VTVM across a Dummy Load (8 ohm) between Pin 1 and Pin 2 of ACC connector. When turn on the SW, adjust VR10 for 0.4 V reading on the AF VTVM. |
Test equipment required:
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Power Supply: 13,8 V |
Dummy Load 8 ohm |
AF VTVM |
Oscilloscope |
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HF SSG: |
28.000 MHz |
1 kHz |
30% Mod. |
Preparation alignment:
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NB SW |
Off |
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PA SW |
Off |
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Beep SW |
Off |
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VOLUME |
Max. |
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RIT |
Middle position |
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Mode |
AM |
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Squelch |
Min. |
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DX/LOC |
DX |
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Frequency |
28.000 MHz |
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Step |
Condition |
Adjustment |
Procedure |
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1 |
AM |
L1 L2 L3 L4 L5 L6 |
Alignment of sensitivity. Adjust coils for maximum reading on the AF VTVM. |
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2 |
AM |
VR2 |
Alignment of Squelch. Set Squelsch to maximum. Adjust VR2 so that the squelch just breaks. |
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3 |
AM |
VR1 |
Alignment of S-meter. Adjust VR1 so that "9" LCD just lights on. |
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4 |
FM |
L401 |
Adjust L401 for maximum reading on the AF VTVM. |
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5 |
AM |
L203 |
Adjust L203 for maximum reading on the AF VTVM. Noise Generator output: 50 Hz SQ wave 2 V P-P. |
Quieting of AM reception and improving gain of incoming signals is a common request from radio operators. In the first stages of the HF input 2SC1674 transistor can be found. This transistor is responsible for the amplification of a small detected signals. A problems exist if the transistor itself is noisy as is such the case of the 2SC1674 when compared to other low noise packages. Along with the amplification of the incoming signals is transistor noise. Replacement of this transistor with a higher gain, lower noise transistor greatly improves the signal to noise ratio of your receiver.
We will use an 2SC2999 transistor that has higher gain lower noise characteristic. Replace the
Test equipment required:
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Power Supply: 13,8 V |
Oscilloscope |
Frequency Counter |
DC Voltmeter |
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Preparation alignment:
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PA SW |
Off |
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RIT |
Middle position |
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Mode |
AM |
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Frequency |
28.000 MHz |
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Step |
Condition |
Adjustment |
Procedure |
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1 |
AM |
L315 |
Connect the Oscilloscope and Frequency Counter to TP306. Adjust for 6.200 MHz +/- 20 Hz |
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2 |
AM |
L318 |
Connect the Oscilloscope and Frequency Counter to TP304. Adjust for 38.6950 MHz +/- 20 Hz. |
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3 |
AM |
L317 |
Connect the DC Voltmeter to TP 303. Adjust for 6.5 V +/- 0.1 V |
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4 |
CW |
L117 |
Connect the Oscilloscope and Frequency Counter to TP1. Adjust for 10.695 MHz +/- 20 Hz |
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5 |
LSB |
L118 |
Connect the Oscilloscope and Frequency Counter to TP1. Adjust for 10.6925 MHz -40 Hz to + 0 Hz |
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6 |
USB |
L116 |
Connect the Oscilloscope and Frequency Counter to TP1. Adjust for 10.6975 +/- 20 Hz |
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7 |
USB |
VR111 |
Connect the Oscilloscope and Frequency Counter to TP5. Adjust for 38.6975 +/- 20 Hz |
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Adjustment |
Description |
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VR304 |
Amplifier Gain Adjustment |
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Only in President HR2600 |
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Adjustment |
Description |
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VR301 |
DC Balance Adjustment for Balanced Mixer |
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L303 |
9-10MHz Signal Balance Adjustment to Mixer |
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L304 |
14-18MHz Signal Balance Adjustment to Mixer |
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Connect Oscilloscope to IC304 pin 2. |
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Adjustment |
Description |
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VR302 |
DC Balance Adjustment for Balanced Mixer |
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L313 |
22MHz Signal Balance Adjustment to Mixer |
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L314 |
36-40MHz Signal Balance Adjustment to Mixer |
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Connect Oscilloscope to IC305 pin 2. |
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Adjustment |
Description |
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L310 |
High Band Adjustment |
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L319 |
Low Band Adjustment |
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Connect Oscilloscope to Output Terminal for VCO. |
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Band |
Frequency Range (Without ChipSwitch or Frequency Modification) |
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A |
28.000 to 28.4999 MHz |
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B |
28.500 to 28.999 MHz |
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C |
29.000 to 29.4999 MHz |
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D |
29.5000 to 29.699 MHz |
Fvco = F + 10.6950MHz + a
F = Transmitting and Receiving frequency
Fvco = VCO Output frequency
a = 0kHz for CW/FM/AM
a = +2.5kHz for USB
a = -2.5kHz for LSB
