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Hi Reg et al. SSB modulation of the uSDX is very interesting to observe: With Single Tone, we have a near perfect modulation. With Two Tone, we have a high level of intermodulation. My electronic

Pascal's question about SSB distortion in the uSDX+ served to focus my attention on the widely reported problems with severe SSB distortion in the uSDX+. The distortion problem was part of my

Pascal, Thanks for joining. I'm not sure it's great, but it is at least high signal to noise. I'm sufficiently interested in the distortion issue I bought an HP 339A audio distortion analyzer.

Hi Reg, New member here, g’day to all. Have been playing with the QCX-SSB since it’s debut, I realised that I can “gate” modulate a zero voltage “drain-source” switching mode class E

Nice radio. I didn't know that the Argonaut lived on. It certainly should. As an example, for the filters I plan boards for 2, 4, 6 ,8, 10 & 12 bands. I see no reason that the keypad should be

Very nice. Thank you. I'm already sufficiently familiar with the calculations that I'd just use my pocket calculator (very old school, it the coin cell dies I can use my slide rule), but others may

Please look at how the TenTec Argonaut VI handles the keypad issue. Much less room needed. https://www.rigpix.com/tentec/model539.htm All the seldom used options can be in a menu system. Just my

I have made a 3-D printable parametric solenoid coil form. https://github.com/profdc9/RFBitBanger/tree/main/CAD This may be of interest because it is a FreeCAD model that calculates the inductance

Pluggable band modules make a lot of sense, especially in an experimental radio. I need to look at the 4375 as I'm not familiar with it. The Mega328P has a 15 kSa/s 10 bit ADC. That provides a

I have made many PCBs, and I have 40+ open source hardware projects, and I am currently working on my own QRP rig http://www.github.com/profdc9/LittleDX The rig uses the USDX finals, but currently I

I'd like to consolidate this discussion in a single place as multiple lists are getting confusing. I'm quite impressed by the uSDX design concept, though less so about any of the implementations.

After obtaining a non-smoking dummy load for my little transmitter, here's where the investigation wound up: * Breadboard implementation (no ground plane) * Class D operation into a resistive load

... Perfect ! Siemens SIOV protectors: honkin' potted Siemens blue Blocks ! B32K230 B60K385 $5 & $7@ at a Surplus place, new in box

Isolation transformer benefits: superior conducted EMI suppression isolated ground so you can safely use a Variac. Stiff voltage regulator I paid $270 total with shipping and tax for mine.

Hmm... perhaps I'm missing something here.? ? While I have a whole-house protector in the service panel, all I use in addition at my bench is an off-the-shelf consumer device for computer/media

I am thinking of making a batch of DIY WHSP's for my own use: -- Can anyone look in the QEX or QST indexes ?? Simple circuits:? mostly MOV's across the AC lines, and some bits. I think the ~ $300

Not the same brand and *way* more than I paid, but this is what I'm using for my bench. The computers are on UPS https://www.ebay.com/itm/165769191345?

OK a bit of math. I'm using conventional operational mathematics notation where * is convolution and . is multiplication. d(w-w1) is a delta operator in frequency. The normal representation

Seems on topic to me. Safety, EMI/EMC and damage protection are key aspects of owning a lab. I have all my lab gear running off a Topaz 2.5 kVA ferroresonant isolation transformer. And everything

My apologies to David Daniels. I'd completely forgotten I'd made him co-owner. Reg