GW4ALG: 80 m Transceiver

GW4ALG 80 m Transceiver

This home made QRP transceiver covers 3.5 to 3.6 MHz and is CW only. It has the following features:
- 5 watts RF output;
- Full break-in operation;
- AGC;
- Clarifier/Independent Receiver Tune (IRT)
- Crystal ladder IF filter (about 600 Hz bandwidth)
- SWR indicator (LEDs for foward/reverse power)
- Built-in sidetone generator
- 12 v DC operation

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This rig was used in NFD 2000 and was used for my operation as HB/GW4ALG/P.

Block diagram

Block Diagram

Circuit diagram

VFO

VFO Circuit

Receiver Front-End

Front End

AGC Amplifier

AGC Amplifier

Transmit Mixer

Transmit Mixer

Signal Level (Peak-to-Peak Voltage, key down)
'4.9 MHz IN':	1.2 Vpp
'VFO IN':	8.5 Vpp
BF981, g2:	0.7 Vpp
2N2222A, base:	2.5 Vpp
'3.5 MHz OUT':	4.0 Vpp

Driver & Power Amplifier

Driver & PA Circuit

Signal Level (Peak-to-Peak Voltage, key down)
'From TX Mixer':	4.0 Vpp
2N3866, collector:	15 Vpp
2N6456, base:	9 Vpp
2N6456, collector:	25 Vpp
'To SWR Detector':	45 Vpp

SWR indicator

SWR Indicator

Product Detector

Product Detector

Sidetone Oscillator & Audio Amplifier

Sidetone & AF Amplifier

Power Supply & TX/RX Switching

ps.bmp (29118 bytes)

Component connection information

Component Connections