brainwagon

More early reading on vacuum tubes. To be honest, I never really understood (or frankly studied) the physics of semiconductors, which always seemed a bit abstract to me. Having read some of these early texts on how vacuum tubes work, they seem fairly straightforward by comparison. I wonder if I go back and read some […]

I believe that it was the Amateur Radio newsline podcast which mentioned the following: A Miami based Radio Station – The Disco Palace – has started broadcasting a DRM SW channel of ‘best of Disco music’ for listeners in Europe and North America. via New DRM channel of Disco Music  :: DRM. So, today I […]

As part of my delvings into things vacuum tubes, I of course found that many others have been down this road, including this rather interesting receiver built by Alan Yates. Being a novice at this, I was intrigued by the fact that his circuit used the 12DZ6 tube, which could apparently be powered by ordinary […]

For the last week, I’ve been embarking on a ham radio “trip down memory lane”. Well, it would be memory lane if I had any real memories of the tube-based equipment that were staples of the ham shack until probably the 1970’s or so. But if I have a personal philosophy of my little projects, […]

This morning, I see K6FIB back, this time in all caps as he said he would be, along with perennials KC7VHS and WA5DJJ. Good clean signal. Still no trace of him on WA0UWH’s grabber, but KK7CC has no trouble getting him:

Monitoring the QRSS part of 30m this morning for the first time in a while, got this new face: Addendum: A few minutes later, I tuned up the band so I could see WA5DJJ, and got this nice screen grab, along with KC7VHS:

While over at Ham Radio Outlet the other day, I noticed a new QRP/homebrewing book on the shelf published by the RSGB: International QRP Collection, edited by Rev. George Dobbs and Steve Telenius-Lowe. It’s not an ideal book from the homebrewer/QRP viewpoint: it includes a bit too much operating/equipment reviews for my taste. Still, it […]

My trip to Powell’s also netted me Erroll A. Smith’s The American Checker Player’s Handbook, a nice little tome published in 1944. It mostly is an introduction to the famous two-move openings, systematically organizing the forty-seven two-move openings into 7 so-called “Master” openings, and then the Major Variations. There are two principle areas that I’d […]

In addition to the checkers books that I got the other day, I also picked up a couple of radio books. One was an old book on electric circuits (perhaps the subject of a post some time in the future) and the other was this book from Lindsay books on constructing tube-based regenerative receivers. Lindsay: […]

One of the chaps that I talk to occasionally on IRC has built an IOio satellite antenna, and was nice enough to post a recording he did with it while tracking AO-51. A nice little recording, and proof that the IOio has plenty of gain for the receive side. A recording of AO-51 – KJ6AKQ.

Roger, G3XBM once again turned me on to an interesting link, this one on a group of hams who are experimenting with communication over optical frequencies. This is a topic that has interested me greatly in the past (I seem to be interested in the extremes of amateur radio, both in terms of long wavelengths […]

I’ve been a little too busy to fire up the soldering iron and build anything, but I’ve been pondering putting together one of Roger’s G3XBM radios. I ordered a couple of high impedance crystal earphones just to be ready, but in the mean time, I’m studying the circuit diagrams fairly closely: XBM80-2 An Experimental 80m […]

This month’s QST had a pointer to a potentially interesting voice codec that I hadn’t seen before. It appears that Broadcom has developed a voice codec, and released it under the terms of the GPL for royalty-free use. It’s actually two codecs: one at 32kbps, and the other at only 16kbps. I haven’t done much […]

Looks like an RTTY contest is currently going on, and nothing is better for revealing band openings. I tuned up to 15m to see what was going on, and the normally quiet 15m band was alight with stations: Imagine what the band would look like if I had a real antenna! Addendum: 20m is even […]

Here is the tiny clever bit from last night’s demodulation experiment using HF radiofax. For the purposes of this experiment, I record a single channel audio of the HF fax transmission. The audio is centered at an audio frequency of 1.9 Khz, and varies (except for start/stop pulses) between 1500 and 2300 Hz. I begin […]