The phase 3 is
assembly of a local oscillator, Si570. If the
previously installed microprocessor (phase 2) can be
described as 'brains' of Genesis G59, then the local
oscillator is the 'heart' of G59 transceiver.
It is very important that special care is taken while
assembling components in LO section, especially with
orientation and soldering of Si570 and other SMT
components.
The components installed in this phase are marked with
letter G in
suffix.
For the component values refer to component data
sheet which is supplied with your kit.
In this phase you will be installing
components outlined in red.
Component
placement
Click Picture
to Enlarge
Click Picture to
Enlarge
The first step is to install Si570 circuit.
Note the orientation of the IC and position of pin 1
(top left corner).
Do
no overheat while soldering ! Do not apply any solder
directly onto the pins of Si570. Instead heat up the
pads on PCB board and apply small quantity of solder
until it melts underneath the Si570 pins. If required
remove protective solder mask layer (red protection
film) from pads 7 and 8.
Make sure that Si570 is positioned exactly in
the centre of PCB layout.
Install SMT capacitors C5G, C18G and
C19G.
Installation of
IC3G
Note the position of IC3G in relation to pads of two
other SMT integral circuits (bottom
layer).
Align the
IC3G over pads and position the pin index mark to
the top. Solder it with minimum heat required to
reflow solder between pin pins and pads.
Installation of capacitor C16G
(through hole) and C17G (SMT)
Note: Follow the instructions of
installations of above capacitors exactly as described
below.
Locate the holes for C16G on the top of the PCB.
Solder
C16G leads carefully using minimal amount of solder.
Do not run the solder onto square SMT pads.
Cut off the leads as close to PCB as practically
possible.
Position
the C17G over the square pads and solder.
Installation of
IC2G
Locate
the position of integral circuit IC2G (bottom
layer).
Position
the IC2G over the pads as shown on photo
below.
Note that IN pin is marked with white dot and
has pointed lead.
Install
SMT capacitor C12G (bottom layer).
Install
inductors L1G and L2G.
Install resistors R1G to R11G.
Install
resistors R12G to R19G.
Install
capacitors C1G, C2G, C3G, C4G, C6G, C8G, C9G.
Install transistors TR1G and TR2G.
Install
electrolytic capacitors C13G and C15G (C15G capacitor
is not shown on the photo, it is located above resistor
R12G).
Install
capacitor C11G.
Note: capacitor C11G connects output of IC2G
to input of IC3G.
Install
resistors R8N and R7N which are located at top middle
part of PCB close IC3S power supply section.
Resistors R8N and R7N provide +12V to IC2G. If
you fail to install them you will have no power on
amplifier IC2G !
This
completes assembly of phase 3.
Voltage and frequency check
1. Connect 12V DC
power supply to plug DC1S.
Note: Do not connect USB cable yet
!
2. Check
voltages on the following pins of IC1G
(Si570).
| pin |
voltage
[V] |
| 1 |
0 |
| 2 |
3.27 |
| 3 |
0 |
| 4 |
1.16 |
| 5 |
1.16 |
| 6 |
3.19 |
| 7 |
3.25 |
| 8 |
3.25 |
Si570 current
consumption
Measure
the voltage over resistor R5G. It should read
approximately 83mV which correspond to current
consumption of 83mA.
LO frequency check
Upon the
power up the Si570 will oscillate at a default
frequency of 56.320 MHz.
Connect frequency counter to pin 4 and 5 to check the
LO frequency.
IC2G
amplifier voltage check
Check voltage of IC2G (IN +2.84V and OUT +4.38V)
IC3G
divider: output voltage check
Check voltage on resistors R12G to R19G. The output
voltage should be +1.65V.
IC3G
divider: output freqency check
Connect the frequency counter to resistors R12G to
R19G. The frequency output should read 14.080
MHz.
Next phase: G59 USB connection to GSDR software
Block
Diagram | Phase
1: Power Supply | Phase
2: Microcontroller circuit | Phase
3: Local osciallator Si570 |
Phase 4: G59 USB connection | Phase
5: G59 Receiver assembly | Phase 6: G59 Input-Output HP-LP Filters |
Phase 7: Band pass filters and control logic
| Phase 8: CW monitor
| Phase 9: Transmitter circuits assembly
|
Phase 10:
Microphone preamplifier
| Phase 11: Si570 Quasi oven circuit
| GBOX assembly
|
