5 watt, 80 meter QRP CW Transceiver
Posted on Oct 31, 2012 4946
1. Full 5 watt output using a power MOSFET final that is resistant to high SWR and thermal runaway. This final is very efficient and runs much cooler than traditional bipolar designs. 2. Highly sensitive and selective superhetrodyne receiver with plenty of audio to drive a speaker. About 100 Khz of tuning range is provided through a varactor diode along with a switchable RIT control. 3. Full break-in keying with a unique T/R switching system. Work is continuing on a printed circuit board and this circuit is expected to be available as a complete kit including all electronic parts, PCB and instruction manual at a future date. My prototype was built on Radio Shack universal boards.
This month, we`ll begin by building the VFO. The VFO uses a JFET for stability and a varactor diode to provide the necessary tuning. Many other JFET`s such as the 2N3819 or 2N4416 can be substituted for Q1 and Q2 but pay attention to the pinouts