The Completed Transceiver-G3VPX


Pic-A-Star - building a box for it

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Front View
Push button and tri-colour LED to right of mic socket are for SWR indicator system which uses the 12-LED S-meter and is under development.
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Rear View
Phono for linear switching, small jack sockets for PC link an audio out, CW key, power, on/off switch, earthing terminal. Note there are three PC link sockets - an extra one is to link the SWR PIC to the PC calibration software.
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Side View
Supports for top and bottom are soldered pieces of brass angle. SWR bridge unit now added botton right.
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Side View 2
Note the G6ALU logic and timer boards mounted vertically beneath the BPF unit. SWR PIC board added bottom right.
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Underside View
Fuse and reverse protection diode for PA bottom right. Screened power lead from fuse to PA is 5A mains core replacing central core in a piece of RG58.
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Top View
7 LPFs - separate for 7 and 10Mhz.
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Detail of PA compartment mounting
driver amp in brass box and screened compartment for antenna soclet.
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DDS filter
in brass box Pletronics 200MHz osc unit middle left - before addtion of Harry (G3HNR) heater.
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Harry (G3HNR) Unit
heater / temp control unit added to crystal oscillator. 8v regulator for this at top.
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PICSWR board
Working but much work to do on calibration software. Use PIC16F876 + 20Mhz Xtal. Other chip is ST232 for RS232 communication with calibration software on PC. Forward and reflected voltage from SWR bridge are fed to two ADC inputs of the PIC.
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SWR bridge
installed in LPF enclosure. On transmit, the PIC sends serial data to the status board 12-LED display for forward or reflected display. A small push button and a triclor LED on the front panel allow stepping through Tx options:fwd -refl.- low power refl - ?swr -Star default. On receive the PIC passes serial S-Meter telemetry from the DSP unit straight through to the 12-LED display.
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SWR bridge Rear
close up.
created with darktable 4.6.1