Kit Progress

By JonathanGuthrie, 25 July, 2018

A year or two ago, I bought a dummy load kit at the Texas City Hamfest. It's basically a bunch of 1K 3W resistors, a mason jar, a couple of perforated metal disks, and an SO-239. Some assembly required. I made some changes to the design, replacing the SO-239 with a BNC connector, and adding BNC connectors for sample and AM envelope detector outputs, and it's now done. The guy who sold me the kit gave me way more than 20 resistors, though, so I have a bunch of 3W resistors left over, not to mention the fact that I misplaced the resistors so I bought even more. I've got enough resistors to build at least three more of these things, but who needs four dummy loads? I want to build one more to see if I can do better than the perforated disks that don't work very well for soldering bunches of resistors to.

Anyway, I wanted to test out this new dummy load, and I wanted to test it before immersing the resistors in mineral oil, and I had an S-Pixie kit that I bought incredibly cheap from which I'd never gotten completely working, so I figured what he heck? It's only supposed to put out about a watt, so I wouldn't need the oil. I hooked it all up and, nada. So, I looked into what was wrong to see if I could figure out what's wrong.

Well, now I know what's wrong with the S-Pixie. The 1uH inductor that's in the low pass filter is defective. It's an open circuit. So, I've ordered a fixed inductor assortment from Taiwan, and when it gets here I'll have a chance to check out my new desoldering pump and the, as of yet still untested, dummy load.