Monitoring the control voltage of an added AGC circuit or the output of a logarithmic detector such as the AD8307 can give a useful S-meter indication. A diode detector on the audio read by a 10 bit A

The MAX7400 is a low pass filter, however if the uBitx crystal filter is doing its job there should already be a sharp lower cutoff frequency of around 300 Hz. So the total system is effectively a goo

The MAX7400 switched capacitor audio low pass filter is an interesting part. Simple to use, and only draws a couple ma. Has an internal oscillator that Andy is tuning with the 1n4148 used as a varicap

Easiest is to add an audio filter of some sort between the phone jack on your uBitx and your headphones. For most of us, easiest means best. Strong adjacent signals will cause audio distortion, for th

I'm fine with letting conversations wander where they will, so long as folks remain civil. A good way to learn more about other forum members. Though admittedly, that EFHW thread did get kind of long

Normally you could take this up with the group moderator. But in this case, perhaps your best plan is to start your own forum. ;-) 95% of the messages here aren't of much interest to me. That's OK. So

You want one set of pullups to 3.3v on the i2c bus, the ones on the Raduino for the si5351 are sufficient for this. That i2c bus is relatively slow, if you load it down with traffic from Nano to Teens

If building a new board for external low pass filters, could spend an extra $0.50 on a processor to interpret serial commands from the Raduino. If wires kept short could use the i2c bus, pin count imp

I agree with Curt. A good student project would be to get the uBitx, and then try to improve it somehow. Lots of fodder in this forum if looking for ideas of what to do. Jerry

Jonathan, A search on the web and on ebay for "ssb transceiver kit" gives a few kits that require more assembly than a uBitx, but none that I am familiar with. Perhaps the Klopik out of Russia, if wan

Jonathan, Be aware it might not be as trivial as it looks. The transformers are described here: http://www.hfsignals.com/index.php/ubitx-circuit-description/ Search for "Coil Details". The KiCad files

Could be that you got bad parts. Or could be that the part is getting too hot, and going into thermal shutdown. So you need a better heatsink. On page 2 of this Fairchild datasheet for the LM78T05, it

Gus, If the display freezes up that means the Nano has gone off the rails for some reason. First, make sure that the 5v supply on the Raduino coming out of the LM7805 is a good solid 5v when it fails.

#ubitx #ubitx-help

Mark, >> I double checked for polarity being backwards and it is wired correctly... > The bench power supply is outputting 12v and 2 amps, but at the bitx the voltage drops to 0.49v So, you measure 12

Like Ian, I think the uBitx main rail is a good candidate for a series diode. We don't care much if we lose a half volt there. The hfsignals.com wireup diagram shows a shunt diode that conducts if the

#ubitx

Nothing terribly wrong with what you have done, seems better than most I've seen described here. But I'd have a switch in line with the PA-PWR, as you suggest. When the power switch for the rig is off

#ubitx

Putting things like diodes and switches on the ground return back to the power supply is a bad idea. There are many other ways that the ground return could be completed. For example, some power suppli

The BNC socket included with the kit is not machined to tight enough tolerances, the hole to receive the pin is cut too large in some cases, and the center conductor is an open circuit. This is not an

#ubitx-help #ubitx

As I mentioned in a previous email, there are issues with the documentation on hfsignals.com They do check the boards before shipping, but it is still possible to have trouble bringing them up. Most o

That video is dated Dec of 2016, right when they started shipping with the Raduino (and thus with L4 not installed). And at the very start of the video, Farhan states that the unit he is debugging has