开云体育

Hi all As is normal, none of the MLCC in the QMX have any markings are all. So where are any of you seeing "103" on a capacitor which is supposed to be "225" (2.2uF)... I'm feeling lost... 73 Hans

Mike, Yes, it's connected by a trace. Walt - KK4DF

Steve, Thanks so much.? I completed my QMX build today, went through all the preliminary power board checks, loaded the firmware, and began testing.? No power out on any band!? Your inspection #3

No marking, it's just an unmarked tan SMD.? The component next to C509 is resistor R510. C510 is closer to the USB port, and is also a tan, unmarked capacitor.

Rick! What is the marking on your C509?!

Hang on, I was looking at R510, which is right next to C509. Maybe that's what you saw too, Karl.

Hello all, I just finished building my first QRP Labs project, a QCX-Mini for 10 meters.? I am new to this group and this is my first post.? Is this the appropriate group to discuss the QCX-Mini??

My C510 is also marked 103, which is 0.01uF, as you mentioned. I can confirm C510 is listed as 2.2uF in the assembly manual. That said, my QMX works fine. Would it work even better with the specified

Hi, Can anyone confirm somthing for me on my QMX build.? On the power supply board the central one with 3/3 pins. Looking down onto the plug when it is plugged in, is the centre pin conted to Q101

Ok, looking more closely at both, my Q103 is clearly further away from Q104 than Giuseppe's is. So Giuseppe, be careful and be extra sure there's no short between Q103 and Q104!

Q103 and Q104 can look close, but still be ok. There's close and then there's too close. Mine pictured here are fine, no problems.? Q103 is centered on its pads. Although the tab extends off the pad

Pathway for receive is exactly what I thought! But C510 being marked with "103" means 10 + 000 or 10000 pf = .01μf... right? Parts says 2.2μf. That marking should be "225" or 22 + 00000 pf = 2200000

If you look at the TAB of Q103, it looks like it's sitting on one of the contacts of Q104. Looks like you need to move Q103 away from Q104-- The short is to the pad of Q104, there's no way moving Q104

It looks like C509 is a crucial pathway for RX_In

Got that pin soldered that I left un-soldered after misunderstanding the instructions. Have found a missing part! C509 is not on the board. C510 is and it is a 0603 sizes SMD marked "103." C510 is

Thinning the herd a bit.? Offered for sale is my QRP Labs QCX 40 meter CW transceiver. This is the "classic" model. Firmware is at version 1.08. Transceiver is mounted in a Ba-Ma-Tech aluminum case.

Karl, THIS MIGHT BE IT: *Make sure your QMX is set to VFO A before performing the RF sweeps.* If it's set to VFO B, the RF Sweep doesn't work right and shows graphs like you posted. Yeah, I just had

From my experience swapping them made it worse. I used new capacitors so their values may have been not exactly the same as the originals, but they should have been as they were marked correctly.

Karl, there is one more fix for you to make. Refer to http://qrp-labs.com/qmx/qmxtrouble.html the section *Low 20m output power on early QMX builds* Capacitors C525 and C516 values incorrectly swapped

Dan, When you have IC403 removed, check the voltage at the junction of R401 and R402, in both receive and transmit. It should be 2.5V in both cases. If you have a short at one of the bandswitch