Within fifteen minutes I had dug up two generic QRP kits and a 2400 Bd ISA modem with a nice 1:1 audio transformer. One kit didn't work. I didn't want to waste time trouble-shooting it, so I tried the second one, a 20m TX. 20m rig works fine, varactor circuit works fine, now for a quick modification. A copy of the schematic for the 80m rig that didn't work is above. Aside from component values, design of the 20m rig is the same. It would appear that the easiest way to modulate this CW TX would be to alter the voltage and frequency between the wiper of R1 and where it connects with R2 and C1.
No comments:
Post a Comment