Alinco Dj-296t Circuit Description Manual

CIRCUIT DESCRIPTION  DJ-296T  
1) Receiver System
The receiver system is a double superheterodyne system with a 30.85 MHz first IF and a 455
kHz second IF.
  
1. Front End
The received signal at any frequency in the 216.00 to 249.995 MHz range is passed through the
low-pass filter (L2, L3, L8, C2, C9, C10, C11, C62 and C189), high-pass filter (C56, C57,
C58, C61, L22, L25 and D15), and amplified by the RF amplifier (Q9). The signal from Q9 is
then passed through the tuning circuit (C12, C14, C65, C66,...

ADJUSTMENT  DJ296T 
1) Required Test Equipment 
The following items are required to adjust radio parameters: 
1. Regulated power supply   Supply voltage:       5 - 14 VDC  
                         Current:             3A or more 
2. Digital multimeter        Voltage range:        FS = Approx. 20V 
                         Current:             10A or more 
                         Input resistance:       High impedance 
3. Oscilloscope             Measurable frequency:  Audio frequency 
4. Audio dummy...

•  All SSG outputs are indicated by EMF. 
•  Supply voltage for the transceiver: 13.8VDC 
   
2) Adjustment Mode 
The DJ-296 does not require a serviceperson to manipulate the components on the printed-circuit board, except 
the trimmer when adjusting reference frequency and deviation.  Most of the adjustments for the transceiver are 
made by using the keys on it while the unit is in the adjustment mode.  Because the adjustment mode 
temporarily uses the channels, frequency must be set on each channel...

Reference Frequency Adjustment 
1. In the adjustment mode, select channel 1 by rotating the main tuning dial. 
2. Press the PTT key to start transmission. 
3. Rotate TC1 on the Main board until the value on the frequency counter matches the one displayed 
on the LCD. 
  
High Power Adjustment 
1. In the adjustment mode, select channel 2 by rotating the main tuning dial. 
( “L” at the upper-left of the display disappears). 
2. Hold down the PTT key to start transmission. 
3. While watching the reading of...

S-meter (1) Adjustment  
1. In the adjustment mode, select channel 7 by rotating the main tuning dial.  
The S-meter will show a single star. 
2. Enter “0” dBu (EMF) with the transceiver tester.  
3. Press the F key. The transceiver beeps indicating the new setting has been stored successfully.  
  
S-meter (FULL) 
1.In the adjustment mode, select channel 8 by rotating the main tuning dial. 
 The S-meter will show all six stars. 
2. Enter “+20”dBu (EMF) with the transceiver tester.  
3. Press the F key....

DCS Code 255 Test  
This function is only for checking the DCS, not adjusting it. 
1. In the adjustment mode, select channel 15 by rotating the main tuning dial. 
2. Press the PTT key. A 255 DCS code is automatically sent. 
3. Check the deviation with the transceiver tester. 
  
Tone Burst Test 
This function is only for checking the tone burst, not adjusting it. 
1.In the adjustment mode, select channel 16 by rotating the main tuning dial.  
2. Press the PTT key. A 1750Hz tone burst is automatically...

SPECIFICATIONS  DJ296T
GENERAL
Frequency coverage         TX: 222.000 – 224.995MHz
                         RX: 216.000 – 249.995MHz
Mode                     F3E (FM)
Channel steps               5, 10, 12.5, 15, 20, 25, & 30KHz
Memory channels           160 channels + 1CALL channel
Antenna connector          BNC (50 ohm unbalanced)
Frequency stability          +/- 5 ppm
Microphone input impedance  2K ohm nominal
Power supply requirement     7.0 to 16.0 V DC (negative ground)
Current drain (at 13.8 V DC)...