Thought you would appreciate a recent project inspired by the fabulous EMRFD. This started as a test bed W7ZOI universal tx to evaluate my stock of RF BJTs and employ some FT-243s in the shack. That was interesting by itself but the 16-32 dBm output (choice of device really matters!) did not reach the intended targets using my 40m dipole. So, add a W7EL RF PA and a nifty, clean 7W emerges after damping output from Q2. The final is pleasantly efficient and needs only a modest heatsink to survive key down for 60 seconds. KFS then reported S7-9. Success. Time to box it up and go XTO, add a meter output at 30dB down and an RF driven LED indicator. Left room to add an ATtiny85 CQ keyer but ran out of time. Had to move house and knock down my 40-6m antennas. That was the most painful part of moving. So this rig sits while I find a new place to hang antennas. Eventually, the TX will get a RX mate when it is possible to box up a 40m DC RX with Si5751 and OLED display. Am still trying to solve how to mount an OLED display cleanly in an aluminum box. First, I have to reconstruct my workbench.
Keep up your good work, and that is no April Fool’s joke.
73,
Chuck KE5HPY
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This is a very nice transmitter that you could use to check-in to the Sunrise CW Net on 7.123 MHz, especially on Sundays when KA5TJS of Texas is the net controller. (Mouser has a 7.124 crystal
ReplyDeletein stock that would work.)
Also, this project reminds me that just tuning in to a WEB SDR with a computer or smartphone makes a great receiver, so building a transmitter first really makes good sense these days in my opinion.