The Yun is pretty cool. In addition to the Arduino compatible ATMega-32U4, it has an Atheros AR9331 running linux. From https://store.arduino.cc/usa/arduino-yun ############## The Atheros processor su

Sounds like a bad solder joint, making an incomplete connection at times. I'd get it working on receive, then try pushing stuff around with a finger to see if I could get it to fail. Perhaps around th

#power #v5

Could indeed be a defect in both the Biennio BMS and in the uBitx, as you suspect. Very weird that the uBitx works (for awhile) with the Biennio, but not with a bench 12v supply. You could be right th

#power #v5

Tim, Hmmm, radio only powers up when tied to a big battery capable of supplying several amps, not when powered from a wimpy 1 or 2 amp 12v supply? Check current consumption into the uBitx when receivi

#power #v5

For portable radio use, lithium ion is ideal. Very light weight, and you know to stop charging when you reach a specific cell voltage. And even for our large off grid battery in the basement, a used p

I've been planning to build an arduino based battery evaluator as well. > My idea was to use a power transistor as a current sink into a dead short and draw it down to the low set point while monitori

Ken, Looks like you convinced Arv and Farhan. And actually, I agree as well. But given the exponential growth of this pandemic and the dire predicament that regions a week or two ahead of us are in, I

The first 1000 Tesla/SpaceX ventilators have been delivered: https://www.businessinsider.com/elon-musk-ventilators-coronavirus-gavin-newsom-arrived-california-2020-3 Impressive, was just vague talk la

Ken, Your best bet is convince the forum moderator, that would be Arv: https://groups.io/g/BITX20/message/77310 I suppose you could check with Farhan, he may still have some pull here: https://groups.

Have thought about this for all of 10 minutes. A few things come to mind, perhaps already considered My primary concern: 25psi will pop a lung. Perhaps an extra fail-safe that senses pressure going in

Yup. Here's an old thread on adding a separate CW crystal filter to the uBitx: https://groups.io/g/BITX20/topic/32840565 Jerry, KE7ER

I suspect the dimensions Jack gives here are in inches, not milimeters. RF currents in a mag loop can be astonishingly large when at above QRP power levels. For the caps shown in the photo, those curr

Arv, Here's something you'll want to remember: You just know too much https://www.agingcare.com/articles/seniors-brains-slower-because-of-too-much-information-167093.htm Jerry, KE7ER

Yes, a linear 10k pot for tuning the Bitx40. Original surface mount Bitx40 used a 10k linear pot on a varactor diode for tuning. Same as Bitx stuff going all the way back to the creation event, which

I agree, I hate using an encoder switch for a select, you often move the encoder a tick or two when you try to push it. Also, as previously mentioned, you have to hold the rig down with the other hand

Yup, I've been thinking of doing that for several years now. But you still need a button of some sort to actually make a menu selection. Jerry, KE7ER

Two encoders, one for each hand. If right handed then left hand sets the tuning speed, and verse-visa. This could feel strangely familiar to those who cut their ears on a regenerative receiver. Jerry,

Here's how calculate the quiescent current, so no signal present: For DC, T9 is just a piece of wire, and the 2.2 ohms at R89 is small enough to be disregarded. So we have 12v across R85,R86, and the

#v6 #ubitx

Unfortunately, harmonics on the v3,v4 are significantly worse when the relays are in sockets. See this thread: https://groups.io/g/BITX20/message/61018 Do not use sockets for the three relays used to

#ubitx-help #v3

These caps have been removed since the first uBitx ever shipped, which was the v3 board.

#ubitx #v6