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I found an analysis of tantal dish capacitors ( https://www.utmel.com/blog/categories/capacitors/various-reasons-for-the-failure-explosion-and-burning-of-tantalum-capacitors ). It's worth reading and

Hello brains trust, Well firstly, on the assumption that Hans will read this - well done on an amazing design.? The more I learn about this radio the more impressed I am. My status is overall pretty

Hear hear, THANK YOU, great idea Ted... I think adding an #experimental tag to the topic subject line would be a great way forward; that way we can continue to encourage and learn from all the

Hi all Thanks to Muhsin TA1MHS for sending me the attached page 9 advertisement from the latest Nov 2023 QST magazine. Since some of you guys love a good story, pending the maybe-someday-forthcoming

Experimentation is at the heart of amateur radio. Like any science, that's how we find stuff out and twist our brains into different perspectives. Observe - hypothesise - experiment is how I was

Joe, with this entry you are telling everyone that DHL is a bad supplier. Then you post another message that it's not DHL, but Fedex. If you only read the addresses, you will come to the conclusion

Hello Aaron The BaMaTech enclosure was for the original QCX Classic that I retired in 2020 when I launched the QCX+. If you have a QCX+, the BaMaTech enclosure won't fit. If it's the QCX+, then the

Hi, I agree totally that the BPF is needed here. Even more selective if there would be room for it. Strong signal will be demodulated at the first non-linear element in the receiver front-end, the mux

I built my QDX a few months ago and it passed all the standard tests with flying colors. IIRC, I saw 4-5w on all the bands I tested, using my MFJ QRP power meter. I built it for 12v, and haven't

Hello Ryuji You are correct about average to peak power ratio. But this isn't the point. The point is that there are sophisticated RF Power meters that do thermal stuff or measure r.m.s. Then there

Hans, OK, one more thing. I hope you don't think I'm being argumentative, just exchanging ideas. Ideally, to use ceramics you need several (more than 2) in parallel with some series resistance. I know

http://shop.qrp-labs.com/qcxpcase

Hello everyone, Today I got my 20m QCX + kit in the mail can't wait to get it on the air. I followed the link to MaBaTech ( https://www.bamatech.net/geraetegehaeuse/qcx-gehaeusebausatz.html ) to order

Hi Jim There isn't any baud rate setting. It just has no relevance in this context. USB serial communications in FS USB ("Full speed" use a 12 Mbit/s rate but that includes all the USB packet

Hi all I don't recommend deleting L401 which will have a performance impact - how much, depends on the circumstances. As previously discussed I don't believe the strong IP3 performance of the QSD

Hi Jim There isn't any baud rate setting. USB serial communications in FS USB ("Full speed" use a 12 Mbit/s rate but that includes all the USB packet overhead. Data transmission occurs on the USB

Hans, I did check the ESR of a single 220uF ceramic and it measures 0.22 Ohms at 1kHz. Randy

Hans, I used 2 x 220uF caps rated for 6.3V for a total of 440uF.? The 3.3 and 5V supplies look clean on my oscilloscope. I have used ceramics in my designs exclusively for several years on LED and

Hi Randy Congrats on the successful repair and the DX. Do bear in mind, you're in uncharted territories... A 470uF tantalum is 470uF. An MLCC has a considerably lower capacitance at DC than its rated

When I was replacing some leaky electrolytics on my TS-850's carrier board, my RF engineer friend (who has been doing hands-on design work for space applications for many years), made a pointed