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I’m probably just ignorant but 10 C over ambient doesn’t seem all that hot to me. Anyone have measurements from a working radio? Mark KI4HQK

Update: Testing completed and deemed a success. My seemingly-kind-of-maybe-reversed-looking-shaped sweep had no trouble making a 20M DX QSO on a terrible antenna, so for me at least, this odd looking

D109 is really just a short term fail safe (if the regulator loses control of the 3V supply. It /shouldn't/ get activated unless there's a problem somewhere else (like a short to the +12 supply...) If

You might check D109 (the 3V6zener on the #2 plug-in board. Mine was "soft" and although it began conducting a bit below 3.6 volts, it allowed the voltage to climb above 5 volts and caused a hard

Hello Martin, I have the same problem,? see /g/QRPLabs/message/116603 It seems that there is no ESD protection of the CPU at all, so that you have a good chance to kill it. There was

Seems enough that you were to arrive at the reason. Takes a lot more choking at lower frequencies. -- Allison ------------------ Post online only, direct email will go to a bit bucket.

Hi Gil! I had a brief USB failure as well on my QMX, but did not manage to reproduce the issue again so far. I had an Iambic key connected to the QMX and configured as straight key to play with my

Hi pls look at: https://github.com/WB2CBA/Barb-A-Watt-QRP-POWER-and-SWR-Monitor https://www.eham.net/reviews/view-product?id=15586 /g/QRPLabs/topic/88936360 73 de muhsin TA1MHS

Allison, I didn't think those toroids would be enough, but I figured it wouldn't hurt to try. ? -- 73, Dan? NM3A There are moments when everything turns out right .... Don't let them alarm you;

I still think the least expensive, educational, and accurate mWattmeters are the ones from China listed on various sites like eBay for around $26. These use the tried and true AD8307 log amplifier

I also see similar results from the RF filter sweep at 20M on my HB QDX. The LB QDX has a mush different sweep. This difference is reflected in JTDX spectrums for the two radios - the HB receiver is

20m, 30m & 80m work on transmit and receive, just need to wait for the replacement inductor to fix 40m & 60m. Other bands do not work on transmit if preceded by trying transmit on 40m/60m a self

At 7mhz range you need a FT43-240 (large core) with at least 22 or more turns of RG316 (or 174) to effectively choke the currents. -- Allison ------------------ Post online only, direct email will go

Garrett, I believe you got it, spot on! I set up the antenna in the yard similar to my POTA setup. I got a very similar NanoVNA sweep with lowest SWR 1.15:1 at 7.060. Connecting to the QMX, I got

Thanks Dean; the copper tape seems like a good idea, as long as the adhesive layers don't impede heat transfer. In my experience the adhesive is quite thin, and you're compressing everything too, so

Ludwig Hi are we talking about the same thing here? /g/QRPLabs/message/116271 73 de muhsin TA1MHS

Hi Ludwig FYI the toroids in QMX are purchased directly from micrometals in California, US (https://micrometals.com), in large quantities (10,000 or 20,000 etc). I have no reason to suspect they

Sometime back I loaded .10 firmware into my perfectly functioning QMX only to have the same thing happen: high SWR shut down! This is into a tuner and antenna proven to be low SWR by nanoVNA and

Many thanks Allison for taking your valuable time to analyze my data. Yes 'troubleshooting by remote seculation' is indeed an endeavour with limited return on time invested (unless one gets lucky).

Garrett, Interesting thought. I did not have a choke on the feed line. I used a 25' RG-174 feed line and was about 12' away from the antenna inside a closed vehicle. I could easily try the choke. --