Check the relays. If it’s in all bands then check the T/R relay, if it’s just some bands, check the filter relays. In either case bad relay contacts would account for both problems. Sent from an iPhon

#v3 #ubitx #ubitx-help

Check the numbers for maximum charging current to the battery and make sure your panel doesn’t exceed it. A few charge controllers let you set a maximum charge current but most don’t. Clark Martin KK6

If you have a variable voltage supply use that while monitoring the current to slowly increase the supply voltage until the current gets up to around 200 mA. Then start probing see where the current i

Cheap replacement unless it’s failure mode is to send Vin to Vout, then… ouch. Clark Martin KK6ISP

To verify, if you have a low power transmitter (oscillator) that can tune around the offending AM BCB frequency, turn it on near the µBitX and see if you can interfere with the interfering signal. If

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hex files are executable images, i.e. you don’t compile them, they’ve already been compiled and linked. To download it to the arduino you need to use avrdude directly. Something like: avrdude -p atmeg

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It’s the black wire connected to the black terminal. It just has a strip of red from where it separated from the red wire. Clark Martin KK6ISP

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No need to “steal”, you can just “use" it.:) Yes, one MCU’s outputs can certainly be another MCU’s input. No resistor or pull up or down is needed, the output is driven high or low. Any MCU’s input is

One of my goto tools is a logic probe. It’s 30-40 years old, the LEDs are a little hard to read at times but it still works great. It would quickly diagnose a problem like this by testing each pin of

Additionally, for the SSB tests what was the AF signal source? Clark Martin KK6ISP

Sorry, but you description below is akin to bad driving directions… (turn right at the green house, etc). It would be far easier and more accurate to specify where the signal was measured (and how). i

Use an RF probe or oscilloscope to trace the signal through the relays / filters. Clark Martin KK6ISP

Except that you’ll have voltage across the PA V+ and main V+. If the PA V+ is actually negative the parasitic diode in the final transistors will conduct and you’ll have reverse voltage to the main V+

Years ago I zero beat (although I didn’t call it that) an NE555 running at 60Hz to the AC line by connecting an analog voltmeter between them. As it neared zero beat the meter started swinging back an

What is the idle current into the PA with the mic PTT pressed (or the equivalent)? It should be 400 mA max. That’s measuring the power just into the PA section. The radio as a whole should be 500mA ma

#ubitx-help #ubitx #v5

If you are in or near the US, try tuning in WWV on any of it’s frequencies. Clark Martin KK6ISP

I’m quite familiar with reactance from years of working with it. Clark Martin KK6ISP

Quite normal. The receiver input is to a mixer through a transformer. At DC the transformer shows approximately 0 ohms. And in general many RF devices will show approx. 0 ohms DC resistance for one re

Ah, you picked the good one, based on a Linear Technology chip. Many Buck-Boost converters will not operate well near unity (Vin = Vout), but this one does. I’m using one as a built in charger for a L

Power is always applied to the finals, Tx or Rx. In Tx the bias supply is activated, which, through the bias pots, biases the MOSFETs up to the idle current. If the FETs are heating in Rx it’s because

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