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Thank you Eric.? Got mine this week and transmitted SSB for the first time after 45 years off the air.? Great mic at a terrific price. Now back to my regularly scheduled CW practice. 72 WB0ZJJ South

Found this: /g/QRPLabs/message/84111

Dear Hans, Thanks a lot for sharing the paper, which fits perfect in the monumental amount of info you provide about all the QRP-Labs products. I think anybody interested in the innards of the

My parents got me the QMX 80-20m kit as a present for getting my license in Australia. This is my first time doing something like this but the challenge was very fun here are my problems- 1. when the

Oh boy! :-) I think we might be diving deeper into the thermal rabbit hole than expected, but let's sort this out properly... The heat dissipation of a TO-92 package is indeed lower via the case

Ahh Roelof you are far ahead of my knowledge and possibilities so I have to stick with small challenges. My loop is doing pretty well and I have been thinking of changing to a 4:1 Balun and something

Very interesting, yes, and a bit perplexing. But also very good news, that you have the processor up and running correctly. It may be safe to use in this state, but I am not sure.? You still have

Jouni, did you get the help you need to get your QMX (or QMX+) working again?

One possible and relatively common failure resulting in your original symptoms would be a shorted D109 - on Vdd rather than 12V, but can drag down the 12V line.

Please find your correct schematic here, linked from the qrp-labs qmx page (the one you got is from the qmx+ page): https://qrp-labs.com/images/qmx/manuals/schematics_rev3.pdf This is for both rev3

I have built three of these amps. The output transformer is easy to get wrong with shorting windings. I was extremely careful by pre bending the wire before threading through the cores. They all

There is nearly no heat dissipation over the transistor housing (to much thermal resistance). The most heat dissipation is over the transistor leads. The screw/washer is used to keep the transistor

My QMX+ stopped working after a few FT8 calls. One of the BS170 transistors had blown and there was a short circuit to GND via Q507. While I was replacing the transistors, I realized the possible

Thanks to Evan and Ronald and obviously to Hans for his YouTube. I checked again my QCX+ (built with 1N5819 diode which substracts around 0.4V to the DC supply) on 14,020 kHz: 1. With 12V DC suplly I

I feel your pain.? I have two QMXs and a QMX+; the QMX+ and one of the QMXs require a power cycle after an update, they fail to restart otherwise. Gave me a mini heart attack until I figured it

Allison, Evan and the group: I appreciate the detailed discussion. To clarify, I did test at 100 mA standing bias in "practice mode" (keying PTT but no RF), but I saw no improvement in power output or

Then you must be living off grid too.? ;-) Jerry, KE7ER

Success at last! Never mind. ?Pushed tune button after QMX+ went into update mode and thumb drive showed up. ?Wow talk about frustration! -- Trevor (N0YMA)

I have been trying several times to update my QMX plus to the newest firmware without success. The computer does not recognize the QMX plus. Just for giggles I updated both my QMX’s Without any

I used to work with tubes and their high voltages, even space TWTs with exposed 8000V collector radiators (!), but as I have grown older and hopefully wiser, my personal preference is to keep power