https://tiny.tilde.website/media/O9oD2ardV1Yg3RTlsAc
The AD9850 + Arduino WSPR beacon that a friend and I built was heard across the Eastern US _and the Canary Islands_. This is on 300mW, all powered via USB. Less power than an LED light bulb. Into some wire I tied to a tree about 2m from the ground.
(I had to look up that the Canaries are in Europe when they so clearly look like Africa, I suspect colonialism is to blame).
(I am VE3XEU btw)
Next stop: build a 1W amplifier and aim for the mainland!
@insom #WSPR is definitely all about grepping the deep -dbm signals. But 300mw is ripping. Was it a random end fed wire or a dipole?
Also, do you have a good plan or even schematic for making such #QRP amps or are you homebrewing? I am no hardware dev, but was pondering making one myself for my HF HT and QRP CW radios, to perhaps boost .1w to 5w...?
@insom Oh, that’s grand! The simplest I’ve seen yet, and no doubt good for QRP. Just a noodle of resisters. Yes, I could make that and play with it. I might get an Elmer to help with deciding values to calculate and test.
Thanks heaps!
@Shufei I am homebrewing, which is why I went for the Advanced class license. My amplifier is basically just a Class A common emitter circuit -- like this -- https://www.electronics-tutorials.ws/amplifier/amp5.gif -- with the values being kind of discovered by trial and error for my set up.