开云体育

What if you remove the LED and resistor and drive an Arduino pin directly? -- Colin - K6JTH http://tangokeys.com

My QDX is generally "remote" in my attic at my main QTH, running off a laptop up there, 30 feet feet from where I'll sit and "operate." I like the QDX for remote digital work, because there's no audio

Hans, I was helping a friend who knocked off D103 from his SMPS (Rev2) PCB 2. I noticed that D103 is on the back of the board, while my Rev 1 has it on the front. While checking the pictures of the

Easy way is to check for short across the big yellow tantalum capacitor on each board. Test in both directions with a multimeter on a low ohms scale. It should read open in at least one direction.

good morning Michael, yesterday I replaced the 4 bs170s and the problem remained the same, the strange thing is that I made many QSOs in cw with 5/6W on the bands here in my area, then I tried to

Did you only apply power, or did you turn it on? If the former, you might be OK. If the latter, what happened? I wouldn't think just applying 26 volts would damage the supplies, if they were off...

K3KDW, No, I would not order the new boards.? I believe that you have damaged the 5 volt and 3.3 volt devices.? You could check with Jeff Moore W1NC on QRZ.com for his email address.? He can

That pdf is gold. So I only have a few ohms between vcc and gnd and vdd and gnd. I don’t know what normal measurements are though. Is it worth ordering a fresh set of SMPS boards?

Thanks Hans, I'd tried tracking through the labyrinth of documentation about this but it's very difficult without spending a shed load of time deciphering it.? It it's not obvious it isn't worth

K3KDW, You want to measure the resistance on the bottom of the mainboard with the power supplies removed.? Attached is a PDF with the pin locations. 73 Evan AC9TU

Thanks for the reply! Could you guide me on where to test?

Same here. I ended up finding a seller on Amazon a few weeks ago and grabbed one. Todd K4MSW

I agree, my Motorola Service Monitor has a TO-3 zener diode on a huge heat sink protecting its 5 volt supply. Gotta love brute force.

Unplug the SMPS boards and check the resistance to ground of both the 3v3 and 5v0 supply rails on the main board. If the 3 volt rail shows only a few ohms or less there is a high probability that the

I accidentally fed 26v to my QMX. That's what I get for keeping too many running projects laying around, especially when they require wildly different voltages but the same plug format. Next time I'll

First time installment of a firmware on a new QMX (no EEPROM file) will not initalize all menu settings correctly. In the menu the keyer setting defaults to straight and tip. Change it to to e.g.

If you're interested in ordering the?VIFLY ShortSaver you might as well order them directly from China via AliExpress and save some money. I ordered some from?VIFLY Drone thinking that I was helping

How about just using an attenuator with a bypass for receiving? QRPGuys have one for 25 dollars or so. Don Meyerhoff WA2SWX

Oh, yes, that was a nice trick.? I figured out the problem with 15m is that the cutoff frequency is too low, and 21.074 MHz is actually more than 3dB down.? I did the transmitter test at 19MHz, well

I accidentally plugged in a 26v supply from another ongoing project. Do you suspect I'm ok after replacing the SMPS boards or is this disaster likely more serious?