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Showing posts with the label transistor

Lab Notebook: The Rockmite isn't Transmitting

 KO6BTY took over debug implementation last night. She wired the RF out from the Rockmite directly to Project TouCans antenna out and... Nothing. Looking at the schematic , that leaves a few choices for what's going on. My favorite for the moment, because it's easy, and because the part is actually very bent, is the T/R switch transistor: The transistor is a 2N7000  MOSFET. Wikipedia lists its maximum current as 200 mA and I can see where we could have exceed that when the Rockmite was shaking loose in TouCans (several of the nylon spacers sheered after a fall.) Also, keep in mind that the power bump has more current traveling through this part of the circuit in any event. After that, we'll be looking at whether or not the oscillator is still oscillating. But actually! Good news! If the oscillator weren't oscillating, the receive branch also wouldn't work, and it most certainly is working!

Lab Notebook: TouCans Debug: It Wasn't the RockMite PA Transistor

Since we returned from camping, Project TouCans has been pretty much off the air. We still have receive, a keyer, and a sidetone, but the rig just isn't transmitting. Last week I thought the issue might be the output transistor of the RockMite. It is not. I removed the original transistor, replaced it with a new one, and to no avail! Here's the before And after There was no change in the operation of the rig. No signals were spotted by the RBN or either of the Utah or Half Moon Bay SDRs.