Thanks @richpowers! Hard to say what the parts cost. I already had some of them. For the ones I had to purchase, I bought extras, to have some on hand...

Thank you. It's a piece of 0.06" thick copper-clad @mark - the type people use to etch their own PCB's. I buy mine from a seller on eBay called abcfab...

I don't know how you figure out what power is making it to the antenna Carl, but Neil described how he calculated the DC power input to the final stag...

My AMT3000 clone is all boxed up and, at this point, I'm a little reluctant to drag out the soldering iron again to temporarily disconnect R7 - at lea...

Well, you want to avoid going over 100% on the negative peaks. Occasionally hitting 100% on the negative peaks is OK, but you don't want to go over, o...

@mark - Part 15 stations in the US don't have to pay copyright. One of the major outfits that collects fees from stations who play music does allow Pa...

I wanted to publish full details on how to build that crystal set. It was a beta build of a kit that a very talented feller was producing. My proposed...

It can!

@richpowers - without going into too much detail, the processor issue I was having turned out to be connected with grounding and screening. It's take...

Well, I finished my scratch-build of the SSTRAN AMT3000, and it's working! I'm glad that the manual and schematic were available online, so that I cou...

Yes really. To a DC power source, such as a battery, wall wart, or other power supply, an appliance looks like a resistor. The lower the resistance, t...

In answer to your first question @richpowers, you don't need to limit the current to the PC. It will draw the current that it needs. However, you want...

@carl-blare - a weak on-frequency signal is a good sign. It sounds as if the only device affected was that one transistor in the final. The MPSH17 is ...

I just checked, and the final in the EDM transmitter looks to be an MPSH17. It's the only transistor in the whole transmitter (in a TO-92 package), an...