Re: Does QCX Mini have DIY emission indication function? #qcxmini
John Pagett G4YTJ
Alan,toggle quoted messageShow quoted text
You are right, that there can’t be a single ended indicator. But what the circuit diagram shows and what is reality can differ. Let’s assume there’s some capacitance to ground at the LED. To charge this capacitance, current would flow through one diode (with a smaller amount through the junction capacitance of the other diode). To discharge the stray capacitance, the current will then pass through the other diode, passing through the LED on the way.
I’m not saying that this is what happens, just that it’s a possible explanation.
Tomorrow afternoon happens to be a “do some electronics / radio” session over Zoom with a couple of friends. I’ll lash something up and see what results I get.
Pagett’s axiom - When reality and theory differ, reality takes precedence.
On 17 Mar 2021, at 17:19, Alan G4ZFQ <alan4alan@...> wrote: