so anyway i finally got my little 40m CW transmitter putting out a signal after about three weekends of fighting with it. its based on that W7ZOI design from Solid State Design, the crystal controlled one. nothing fancy, just wanted to build something that actually worked with my own hands before i started buying more commercial rigs.

the issue is the output is sitting around 800mW when i was expecting to get closer to 1.5W based on the schematic. im running it off 12V regulated supply, the IRF510 is getting warm but not crazy hot. i checked the drain voltage and its about where it should be. only real deviation i made from the design was using a 2N7000 in the driver stage because i couldnt find the original specified part locally, figured it was close enough but maybe thats the problem?

also noticed a slight chirp on the keyed signal which i know is classic stuff with crystal oscillators but i thought the buffer stage was supposed to help with that. maybe my layout is messy. anyway just wondering if anyone has built something similar and ran into the same power output issues

the 2N7000 substitution is almost certainly your issue with the output power, that driver stage really does matter more than people think. the original part had better gain at HF and the 2N7000 isnt quite getting the IRF510 gate swinging hard enough, so youre probably not getting full enhancement on the FET. try a BS170 if you can find one, lot of guys use that as a drop-in for driver stages in that design.

on the chirp, check your crystal loading caps and make sure the osc stage supply is well decoupled from everything else. even a small voltage dip when you key up can pull the crystal frequency a bit. i had the same exact symptom on a 30m rig i built a few years back, turned out to be a 100uF cap that was borderline dead. swapped it and the chirp basically vanished.

nice work getting it on the air at all honestly. i spent like two months trying to get my first homebrew thing to do anything useful and ended up scrapping most of it. 800mW on 40m CW will still get you contacts if the signal is clean, so dont get too hung up on the power number before you sort the chirp out. a clean 800mW beats a dirty 1.5W every time