CQ-Log

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CARRIER OSCILLATOR PORTION


Test equipment required:

     

Power Supply: 13,8 V

Frequency Counter

DC Voltmeter

Oscilloscope

       

Step

Condition

Adjustment

Procedure

1

CH: 1
Band: Mid.
Mode: RX

L17

Connect DC Voltmeter to TP1 (lead of R72). Adjust L17 for 1.2 V +/- 0.1 V on DC Voltmeter

2

CH: 19
BAND: MID
POWER: Max.
AM, No Mod.

VC1

Connect Frequency Counter to Ant. jack. Adjust VC1 for 27.185000 +/- 20 Hz on Frequency Counter.

       

 

TRANSMITTER PORTION


Test equipment required:

     

Power Supply: 13,8 V

Frequency Counter

DC Voltmeter

Oscilloscope

AF VTVM

RF Power Meter

Deviation Meter

Audio Oscillator


Preparation alignment:

 

S/RF-SWR-CAL

S/RF

MIC GAIN

Max.

Step

Condition

Adjustment

Procedure

1

CH: 19
BAND: MID
POWER: Max.
AM, No Mod.

L19
L20
L18

At first, turn down the coar of L18 to end. Connect Oscilloscope to TP2 (lead of R79). Adjust coils for maximum reading on Oscilloscope

2

CH: 19, BAND: MID
POWER: Max.
AM, No Mod.

L20
L15
L14

Connect RF Power meter to Antenna jack. Adjust coils for maximum reading on RF Power Meter.

3

CH: 1, BAND: LOW
CH: 40, BAND: HIGH
POWER: Max.
AM, No Mod.

L11

Adjust L11 for minimum difference between the follow conditions of the set:
CH: 1, BAND: LOW
CH: 40, BAND: HIGH

4

CH: 19
BAND: MID
POWER: Max.
AM, No Mod.

VR3

Adjust VR3 so that the needle of built-in TX Power Meter point Brank sone of "Sig. 9"

5

CH: 19
BAND: MID
POWER: Min.
AM, No Mod.

VR501

Adjust VR501 so that the RF output power level is over 1.5 V and under 4.0 V in every channel.

6

CH: 1
BAND: MID
POWER: Max.
FM

VR801

Connect Deviation Meter to Ant. jack and AF Oscillator to Mic jack. Set AF Oscillator to 30 mV output. Adjust VR801 for 4 kHz deviation.

7

CH: 19
BAND: MID
POWER: Max.
AM, No Mod.

VC1

Connect Frequency Counter to Ant. jack. Adjust VC1 for 27.185000 +/- 20 Hz on Frequency Counter.

       

  

RECEIVER PORTION


Test equipment required:

     

Power Supply: 13,8 V

RF Signal Generator

Dummy Load 8 ohm

Oscilloscope

AF VTVM

     


Preparation alignment:

 

MIC GAIN

Max.

S/RF-SWR-CAL

S/RF

NB/ANL

Off

RF SSG

Modulation: 30% AM 1000Hz

Step

Condition

Adjustment

Procedure

1

CH: 19, BAND: MID
VOL: Max.
SQ: Min.
MODE: AM

L7, L6
L5, L4
L1

Connect RF SSG to Ant. jack and AC Voltmeter to Ext. Speacer. Then adjust coils for maximum reading on AC Voltmeter.

2

VOL: Max.
SQ: Min.
MODE: AM

L2
L3

Adjust L2 for maximum output of noise level in LOW BAND CH 1. Then adjust L3 by same way of adjustment for L2 in HIGH BAND CH 40. Ant then adjust L2 by turn CW in LOW BAND CH 1 so that the same noise level of adjustment for L3.

3

CH: 19, BAND: MID
VOL: Max.
SQ: Max.
MODE: AM

VR2

Set the output level of RF SSG to 1000uV. Adjust VR2 for 2 V output reading on AC Voltmeter.

4

CH: 19, BAND: MID
VOL: Max.
SQ: Min.
MODE: AM

VR1

Set the output level of RF SSG to 100uV. Adjust VR1 so that the needle of built-in signal meter point "S-9".

5

CH: 19, BAND: MID
VOL: Max.
SQ: Min.
MODE: FM

L801

Adjus VOL to obtain 2 V output on AC Voltmeter. Set the level of RF SSG to 100uV. Adjust L801 for maximum reading on AC Voltmeter.

       

 

Improved receive gain

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
2SC1674 (Q2) with an 2SC2999 (or similar low noise and high gain transistor) to achieve this improved signal to noise ratio.
Re-Adjust L1 and L2
The gain will improved with more than 6dB with the same signal to noise ratio.

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