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While working on my intended LPFs I've also looked briefly at an LPF for 80m & 60m. A quick linear simulation using QUCS shows that close to 20dB attenuation at 7MHz might be possible for 0.6dB

If this is the one you need? -- Cheers, Chuck

I asked GPT4 and it gave me a complete code segment written in C using the Hilbert transform, which creates a 90° phase shift and mixes it with original signal. I'm not a C expert so can't say how

Phil, The output of D103 should be "approximately" 3.3V (that's not a minus sign) and 2.426V is way on the low side. Grounding the LIN_REG_EN pin and turning the 78M33 OFF is good. Does it stay OFF

Ron, I failed to ask in the last post... how did you derive that value to set?

Presumably when ssb is implemented other modes like psk31. and the like will become available?? or am I on the wrong track? . Paul DJ0CU G4ADF

This might give some idea: https://github.com/threeme3/usdx It is already done. 73 Barb WB2CBA

Pretty sure the idea is to use an EER (envelope elimination and restoration) technique similar to what Guido PE1NNZ implemented on his QCX modification and later (tr)uSDX. There's a big thread here

I know it's not implemented yet, and it's unknown if it ever will be, and I have very little interest in SSB anyway, but I can't help to wonder. What is the original idea? There's a synthesizer

My QMX kit arrived with the short in place. I removed Q104 (the little one) and the pad was still shorted to Q103’s tab. Using just a soldering iron I first lifted Q103’s two leads. ?Then I

Note that for the QMX (not the QDX) There are unpopulated holes for potential use of these diodes at D503 and D504. The jury is out on whether these are needed pending additional testing. -Steve

OK, but how is FT8 a beacon mode? Just call CQ and never answer, and then scrape spots off pskreporter or some such? Or are you listening for FT8 and doing some kind of reverse beacon thing? I

Andy it's exactly what they are guaranteeing they won't do, but that is off topic so won't expand further.

I uploaded photos of my soldered QMX boards and asked it to check for problems, solder bridges, out gave me a whole raft of tips where to look regarding Rx problems, so yes it's very much on topic

Thanks for you ticket reply to my question, Hans. I've ordered one of each Progrock2 and QLG2. It would certainly be considerably cheaper than the alternatives! They will be boxed with a stable psu

Yes Bob but before 2021, where exactly it was trained is a bit of a secret, but for sure the internet as well. Paul DJ0CU G4ADF

Hi Nigel It IS on my ToDo list for U3S... but, I'm sure you can imagine, my ToDo list is not very short. 73 Hans G0UPL http://qrp-labs.com https://www.buymeacoffee.com/g0upl

My impression is that is due to the QMX reporting a 3200 Hz receiver bandwidth, i.e. the digi bandwidth, instead of the actual CW bandwidth. Gary W9TD

Hi Willie, Thanks for prompt response! I will try to expand current scenario, are you sitting comfortably? <grin> Short version: During the monthly beacon team meeting last night mention was made

IMHO, this method is valid also but requires two diodes. Why not eliminate the spike at the source? If you have two QDX, you might try using the L14 diode in one of them and see if it gives you any