|The Corsair 2007 is merely a refined version of the original Corsair.
Lessons learned & feedback from others who have built the circuits have led to the circuit you now see above.
A LM386 audio IC is used to series modulate Q2. The LM386's output on pin 5, sits at half the supply voltage. But is swung plus and minus with the audio being fed to it's input.In the high current version Q4 allows Q2 to draw more current without damaging the LM386.
The PA, Q3, is a IRF530 which is configured as a linear amplifier. To set up you should, by adjusting RV2, set the DC voltage at TP1 to 2.5 VDC. Then by moving the turns on L6 further apart or closer together, get the RF power to read 10 Watts.
It must be noted that Q2,Q3 & Q4 must have heatsinks and that
Q3 & Q4 should be mounted using a TO220 insulation kit.
The table below shows the component changes needed to the PA and Filter section to use the CORSAIR on other bands.