Copasetic Flow

 Project TouCans has been flying with its power source onboard for several months. It occurred to me I've never documented the power system in its entirety. The Battery The foundation of the power system is an Imuto potable laptop charger Using this charger as a power supply for TouCans has two advantages. First, it fits in a Progresso soup can, so it fits the form factor of the rig that's more often than not flying suspended in its own dipole antenna. Second, it has two USB-C ports. One is attached directly to a USB-C power deliver breakout board that then feeds the the latching relay that serves as the on/off switch for the rig's radio and amplifier. The other USB-C port sports a short USB-C thunderbolt cable protrudes from the can and allows the battery to be charged without opening TouCan's case. Choosing the Voltage So, we have a supply that provide up to 100 Watts. But at what voltage? That's what this gadget , an Adafruit HUSB238, determines. It's jumper...

 Soon, I'll get the bandwidth to document Project TouCans entire power supply system. For now, suffice it to say that, like the rest of TouCans, it is non-standard. One of the non-standard issues we run into is that while there's a USB-C cable accessible outside TouCans for charging the internal batter pack, the battery pack's charging indicator is hidden inside of TouCans in its optional batter pack housed in an empty can of Progresso tomato soup. Consequently, we've occasionally not charged the batteries because the USB-C connection was unhappy. Enter the MakerHawk multimeter. The meter acts as a USB-C female to female adapter, which frankly we needed. It also ships with a USB-C female-to-female barrel, I'm not sure why yet. We haven't used it. When we plug the radio in to charge, we plug the charger into one side of the meter and the internal battery pack's charging cable to the other. When the cables are plugged in correctly, (sometimes we have to flip t...

 Those of you familiar with Project TouCans can probably immagine where this is headed Could Project TouCans become Project ThreeCans? Should we have a contest to name the new incarnation? Here's what's going on. I set out to write it about this on several occasions, but haven't carved out the time. Sticklers for detail may have noticed that the keyer sprouted a pair of 5 kOhm resistors in the last few weeks. I still don't have time to explain it at lenght, but let's just say that left to its own devices, I'm pretty sure that ground at the keyer is a negative voltage compared to ground at the input of the keyer chip that lives inside  Project TouCans. This leads to the keyer rebooting itself at best, and occasionally getting so cranky that it just gives up. I believe the whole issue is the largeish amount of current that the Tuna Topper amp pulls down the Ethernet cable that supplies both power and the keying signals. The two resistor make the keyer ground more ...

The latest fun engineering problem in ham radio Project TouCans! There's an unhappy capacitor lurking somewhere! I've realized that what I thought was a water intrusion issue is not. It actually appears to be stray capacitance, but where? And is it even stray capacitance? The main, bad symptom Immediately after charging the battery, the radio when hooked up to the new charged brute merely buzzes. The magic fix There's one way around this that works somewhat reliably, and that's to do what's called a 'battery terminal rub start'. This entails the following Attach the radio to the keyer, (which  also sends p9ower up to the radio in the antenna) by plugging its Ethernet cable in. The batter is disconnected at this state. Attach the keyer's negative terminal wire to the negative battery terminal Do not attach the radio's positive terminal wire to the battery. Intead: Rub the edge of the keyer's terminal wire on the gnurled surface of the positive bat...

 I'm big into using whatever's already lying around for amateur radio, and the laptop batteries complete with an external charger—for a laptop I no longer use—weigh heavy on my mind each time I change out the (8!) AA batteries for the Rockmite 20. Well, I was finally able to put them to use . Unlike a two terminal AA battery, the MKFVP battery has a whopping 9 connector slots. I measured voltages between slots to no avail, I couldn't fine the advertised 11.4 volts I'd hopeed for. Then, the article at  https://www.electroschematics.com/laptop-battery-secrets-part-1  came to my rescue. The article was about all manner of laptop batteries rather than my specific one, but that was enough. The author also noted that the outside terminals of laptop batteries are usually the power delivery leads analagous to the two terminals of a AA battery. I'd measured the voltage between those two connector slots already, and there was nothing... zero volts. However, the author also me...