Design
Progress on CC-Series development proceeds at a reasonably-good clip right now. One of my last big hardware bugs to stamp out is some nasty microphonics that seem to be generated by the combination product detector/BFO. Today, I believe that I made some significant progress towards solving it and wanted to share what I learned. I've done a [...]
Continue reading about Single-Ended Mixers and Reverse Isolation
As I've previously noted, the VRX-1 is a nifty little basic direct conversion receiver, but it has some shortcomings that could be problematic under certain circumstances. Here's a story of one of those issues and the cure that was found. Dave AA7EE purchased and built a VRX-1 kit a while ago but was never fully [...]
I decided to make my initial Project X prototype PCBs at home using the old tried-and-true method of toner transfer (via Pulsar Professional paper and foil). Since I'm a novice at PCB layout, I didn't feel comfortable paying the money for a few proto PCBs from a board house, then finding out that I did [...]
Continue reading about Creating PCBs with "PCB Fab-in-a-Box"
I've been absent from the blog for a while because I've been knee-deep in developing the prototype for the first radio kit for my as-of-yet-unnamed open source kitbiz. The design makes extensive use of JFETs in cascode configuration. JFET cascode amps and mixers are very solid performers, but the issue of widely varying Idss in [...]
I'm up to my elbows in the design work for the 2010 FDIM QRP Challenge, and I think I've come far enough along to give the rig a name. I'm happy to announce that I've dubbed this project Clackamas, in keeping with my tradition of naming my creations after Oregon rivers. The receiver is pretty [...]
A little while ago, I got a hankering to work on a SSB transceiver. It's something that I've never homebrewed before, and it seemed it like it might be fun to tackle. The BITX20 seemed like an obvious choice, and W7ZOI recently published an improved bidirectional amp which would be nice to try in the [...]
While I was away on my honeymoon, I noticed that the upcoming kit that I've been hinting about for months has finally been released. The Four State QRP Group announced availability of the VRX-1 direct conversion receiver. The VRX-1 is a simple 40 meter VXO-tuned receiver (crystal on 7.030 MHz), but it's not your typical [...]
Well, I've pretty much put the finishing touches on my secret QRP project for a well-known QRP club. The beta testers are currently working on building it, and hopefully the club can make an announcement about the kit fairly soon. It's not a very complicated circuit, but it's somewhat novel and has a bit of [...]
