In 2009 I built the above compact 40M CW transceiver. I surprised myself at how good it worked. It uses 4 MMIC devices is VTO tuned and at the time had a IRF510 to deliver 5 or 6 watts of RF.
About a year ago one of those typical screwdrivers in the wrong place caused a catastrophic short and smoked the IRF510 and a bunch of other parts. I replaced the IRF510 with a 2N2219A as I had a bad batch of IRF510's (from Sanchez's boyfriend). It puts out 16 Volts PTP and thus now a whopping 640 Milliwatts.
Last night around 1930 PST, I noted a lot of 40M CW activity (some contest thing) and thought I would drag out this jewel. Well, I did that and after finding all of the stuff needed to make it airborne, it was 2000 and the signals all dropped off the scope.
This led to the Reverse Beacon Network where I was spotted calling CQ on 7030 kHz some 800 miles away running less than 3/4 of a watt. Thus, the conclusion it doesn't take much to get on the air.
But be aware it is a sophisticated superhet design using MMIC devices, a homebrew crystal filter at 5.185 MHz and break in keying via a NE555 TR switch. Sidetone rides along for free. That said you must not lose sight of the fact that a direct conversion receiver with a 7030 kHz crystal-controlled transmitter at 640 milliwatts will give you the same 800-mile RBN spotting.
Check out the N2CQR/KK4DAS High School DCR project and start 2025 with a fun project!
BTW in this rigs' original form with the IRF510 it would beat the pants off of a Paraset and small enough to fit inside Virgina Hall's wooden leg which I believe she named Cuthbert.
Join the Homebrew fun in 2025 -- build something. It is also a great diversion from what is soon to unfold with the new government.
73's
Pete N6QW