marconi basic-7b assembly manual
TRANSCRIPT
8/9/2019 Marconi Basic-7B Assembly Manual
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Marconi Basic-7B Assembly Manual
www.marconi-japan.com
01/05/2010
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1. Tools & Supplies
You will need:
30W soldering iron with a narrow tip.
Soldering iron holder with a moistened
cleaning sponge.
Board
60/40 alloy solder.
Desoldering braid.
Scotch tape
Small needle-nose pliers.
Diagonal cutters
Screw drivers.
Cutter Tester.
Receiver or frequency counter.
12V @250mA regulated DC power source or
dry batteries.
Telegraph key.
Antenna.
Tools are below.
Frequency of VXO is checked by a receiver.
Frequency counters are useful.
You will need a Power Supply.
Or a 12volt 1.2AH Battery.
You will need a telegraph key.
You will need an antenna.
A dipole antenna is recommended
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2. Parts Inventory
Packages are below.
Place small parts onto the check list and then tape
them to in place to make sure you have all of the
parts.
Parts Check List (1)
Parts Check List (2)
Parts Check List (3)
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Parts Check List (4)
3. Practice of soldering
3-1 Making Dummy Load
Solder a 51 resistor on a back of fem
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le terminal.
Bend the leads to finish th
3-2 Making RF Probe
Solder two diodes as in th
Use diagonal cutters to hol
Solder two disc capacitors
Cut the wires. Short wire
long. Long black wire is 5 1
Take off vinyl film.
1W dummy load.
schematic.
d small parts.
as in the schematic.
are 2 1/2 inches (60mm)
/2 inches (140mm) long.
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Solder the wires on terminals of alligator clips.
Solder them together to finish the RF Probe.
4. Installing Stabilizers
Install four long bolts into the holes of the PCB to
stabilize PCB while soldering.
4/10 inches (10mm) in depth
5. Inserting Terminals
Insert the 24 male terminals into the holes of PCB with
pliers.
12VDC = 2
KEY & RIT = 5
VC = 2
CHECK POINT = 2
AF-GAIN = 3
PHONES & SP. = 5
ATT & ANT. = 5
Solder the terminals on the PCB.
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6. Assembling DC power supply port
6-1 DC Connecter & SwitchCut the wires. Long wires are 4 inches (100mm) long.
Red short wire is 2 1/2 inches (60mm) long.
Solder the parts.
Connect the terminals.
6-2 DC plug cableParts
Solder the wires on the connecter.
6-3 TestingSupply plus 12 volts and check the voltage at the
terminals with a tester. The final transistor will be
destroyed if you supply minus 12 volts.
Use a pair of pliers to insert and remove the
terminals.
Insert
remove
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7. Assembling TR switch
7-1 TR switchSolder the parts on the PCB.
Solder 15k ohm to improve timing.
7-2 Key Jack cableCut the wires 4 inches (100mm) long.
Solder the female terminals and a stereo jack.
7-3 Key plug cableParts.
Solder the wires and stereo plug.
CautionA stereo jack and monaural jack are very similar.
A monaural jack has a switch inside.
A stereo jack does not.
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Connect a key.
7-4 Testing
Connect a key to the PCB and supply 12 volts.
Check the voltage at the emitter of Q6.
It will be about 12 volts.
Push down the key.
The voltage will get lower than 0.5 volts.
Check the voltage at the collector of Q5.
It will be about 0.001 volt.
Push down key. The voltage will get about 12 volts.
Use Diagonal cutters and scotch tape to hold
parts while soldering.
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8. Assembling VXO
8-1 VXOSolder the parts on the PCB.
8-2 Variable Capacitor cableCut the wires 2 inches (50mm) long and take off vinyl
film.
Solder the parts.
8-3 RIT Potentiometer cableCut the wires 7 inches (170mm) long.
Solder the parts.
8-4 Adjusting VXO FrequencyInstall the VC and the potentiometer to the PCB.
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Connect the PF Probe, the key and supply 12 volt.
Connect the RF Probe at the CHECK POINT.
Turn the potentiometer anticlockwise to stop RIT.
Tune T2 and T3 at oscillating frequency.
RF Probe will show about 6mA at peak.
Tune T1 and adjust the width of variable frequency.
Use a receiver to check the frequency. The core is at
ceiling, VXO oscillates 7.020~7.040MHz. The core is
at bottom, VXO oscillates 6.990~7.033MHz.
The VC capacitor is full and T1 is tuned at 7.000MHz,
VXO oscillates 7.000~7.035MHz.
Turn the potentiometer clockwise to work RIT.
Push the key down to stop RIT.
Use scotch tape to hold a IC and a jumper wire
while soldering.
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9. Assembling Driver
Solder the parts on the PCB.
10. Assembling RF POWER AMP.
Solder the parts on the PCB.
Making L1Insert the enameled 0.32mm diameter wire into
the hole of ferrite bead to hold with fingers.
Hold the wire and wind the wire 10 turns.
Count up to 10.
1
2
3
10
Take off enamel film with sandpaper.
Pre-solder the wire.
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11. Assembling Low Pass Filter
Solder the parts on the PCB.
12. Testing Transmitter
Connect Power Supply, key, Dummy Load, and RF
probe. T4 is broad. It is not necessary to tune T4.
Dummy load and RF probe is at ANT terminal.
Push the key down in short time.
DC current will be over 100mA.
Making L2 & L3Insert the enameled 0.4mm diameter wire into the
hole of toroidal core to hold with fingers.
Hold the wire and wind the wire 19 turns.
Take off enamel film with sandpaper.
Pre-solder the wire.
The final transistor 2SC2053 will overheat and be
destroyed if you hold the key down too long.
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13. Assembling AF Power Amp.
13-1 AF Power Amp.Solder the parts on PCB.
Solder 1.2k ohm as in the schematic to decrease the
gain from 200dB to 80dB when you want to do it.
13-2 LM386 Jumper wireCut red wire 7 inches (170mm) long.
Insert the wire into +T/R holes and solder them.
13-3 AF GAIN Potentiometer cableCut the wires 4 inches (100mm) long.
Solder female terminals,wires,and a potentiometer.
13-4 PHONES jack cableCut the wires 5 inches (120mm) long.
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Solder them.
13-5 SPEAKER cableCut the wires 18 inches (450mm) long.
Solder wires and a speaker.
13-6 Testing AF Power Amp.Connect Power Supply, speaker, jack, potentiometer.
Turn the potentiometer clockwise.
Touch the AF-GAIN terminal with a finger to check the
circuit. It makes noise when the circuit works.
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14. Assembling AF Preamp.
Solder the parts.
15. Assembling SBM
Solder the parts.
16. Assembling RF Amp.
16-1 RF Amp.
Solder the parts.
Solder D8 and D9 as in the schematic.
Solder 2 7/10 inches (70mm) jumper wire as in the
schematic.
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16-2 RF Amp. Jumper wire.Cut white wire 4 inches (100mm) long.
Insert the wire into +R holes and solder them.
16-3 ATT Potentiometer cable.Cut the wires 4 inches (100mm) long.
Solder them.
16-4 ANT. cableParts.
Solder the parts.
16-5 Testing Receiver Connect the modules to the PCB & supply 12 volts.
Tune T5 & T6. Do not touch T7. It is a transformer not
at resonance. The core of T7 is very weak.
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17. Assembling SIDETONE
17-1 SIDETONESolder the Parts.
17-2SIDETONE jumper wireCut yellow wire 5 1/2 inches (140mm) long.
Insert the wire into +T holes and solder them.
17-3 Testing SIDETONEConnect the modules to the PCB and supply 12 volts.
Do not forget to install the Dummy Load at the ANT
terminal or you will destroy the final transistor.
Tune the volume with VR2.
18. Completion