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Folks, my QMX had the Q103-Q104 issue. I managed to unsolder and move Q103, and now the short has disappeared. I also replaced D101 with a THT one (it went off at first power-on, I had not checked

Hi I probably need glasses but I have searched in vain for the expected current consumption of the QMX built for 9V (or indeed for 12V), when transmitting. The description gives the current on

Hello All I have still not found the problem with this 2nd QMX build. I originally thought this 706Hz tone was the only problem and it still is. However there is a bit more to it than just the

Hello Jerry 77424 is my order. No email when it shipped or if it shipped. It’s been Your tracking number is RR372736230TR You can track it on

I understand your frustration Chris, but the point of this hobby (and I believe Hans' product line) is experimentation and you cannot do that without at least SOME investment in test equipment and

In another message on this platform (that I cannot find right now), I saw a recommendation for the (relatively) inexpensive ?UD18 usb power monitor that also works for 12V devices like QRPLabs uses

I see this as an example of the perfect being the enemy of the good. We are trying to get an idea of the performance of a QRP transmitter.? We aren't measuring the temperature of the big bang. We

Check the accessories that came with your probes! That scope (like most) usually comes with special little probe tips to plug them in to a BNC/TNC connector. It looks funny because it has no outside

Eek, I didn't realize that such small mismatches would have such a huge effect on accuracy... Consider myself corrected.

Hi Steve, The datasheet for the MCU is unambiguous about this in section 6.2 on Absolute Maximum ratings. It is just so easy to be overwhelmed by all the info in the datasheet! I thought it would be

FWIW? ?The trouble with reading power accurately . . . A 1 : 1:05 SWR from a poor match or system implies a voltage reading across 'supposedly 50 ohms' that's 5% different to nominal/expectation

This is a valid concern. Unfortunately it's a very difficult thing to find when the problem is buried in an app note and not clearly obvious in a data sheet. Multiple voltage power-on sequencing

I made this for my QLG2, figured I'd share it. https://www.thingiverse.com/thing:6213918 SMA and USB both mounted on the long axis. I also glued a 3.5mm jack to the USB connector so that I could

Hello Paul What I found is once you've heated up Q103, if you can actually see the solder bridge when you nudge Q103 away from Q104, my trick is to nudge Q103 intentionally CLOSER to Q104. Then nudge

I’ve also been able to move Q103 with lots of flux and hot air. But I always get anxious about damaging components with hot air. ?I’m a lot more comfortable with an iron. ?An alternative that I

I bought a 10W 20dB attenuator from eBay for about ?23, wanted something to keep the spectrum analyser I've borrowed from my radio club happy. This is much better: This looks good enough to get

Here's what my my home made dummy load, cobbled together on a bit of veroboard with 4 x 50R resistors does: SWR varies from 1.03 at 3 MHz to 1.1 at 30MHz, terrible. It's got an attenuator - a 2k2

I have one of these ( http://shop.qrp-labs.com/kits/dummy ) sitting in front of me right now. Very unsophisticated construction, regular old off the shelf 1-watt resistors, the nanoVNA tells me it's

The DIY pad is unnecessary and very special resistors and construction are needed to stay linear and resistive at RF. ?It will give imprecise results at best and as described may also introduce SWR

Yes! ?Put a 39k resistor in parallel with that 10k and you have 50dB attenuation FWIW I use that set up together with an AD 8307 style (set up for -60dBm to 0dBm) power meter. ?That 50dB