brainwagon

Well, I’ve been mucking around with my RF probe circuitry a bit tonight, and encountered something pretty strange. I have two digital multimeters lying around, and my newly rebuilt RF probe/dummy load that I described earlier. I hook one multimeter to it, and I get a reading of 14 volts. I get my other cheapie […]

This duplicates a posting I made on the wsprnet.org website. Aircraft reflection? Or something else? | WSPRnet On Saturday, Jan 10th, I had my transmit-only beacon that I wrote sending both a visual MEPT indicator (the MV that you can see in the attached image) and the WSPR beacon, and tried out a simple program […]

More digging around for information about the RF probe, I found this link to the NJQRP’s presentation at Atlanticon 2000. It’s a cute little QRPP rig built Manhattan style, and includes a discussions of the RF probe setup to measure it’s output. Neat. Atlanticon Kit – It’s a Snap!.

My dummy load experiment still has a few unanswered questions, but I found that the ARRL Handbook has had a circuit which is basically what I built, minus the one series resistor. It looks like this: Okay, they use a germanium diode with considerably lower voltage drop, and include a 4.7M ohm resistor in series […]

G3XBM dug around and found inks to a couple of sites with interesting historic recordings of ham radio transmissions. Here’s one, and here’s another with lots of shortwave recordings. G3XBM’s posting.

Okay, this is pretty basic stuff really, but it’s part of my trip toward additional homebrewing, and it might be of some vague interest, so here we go. If anyone spots anything horribly wrong here, please feel free to help me learn by leaving me a comment here. Before Thanksgiving, I was having quite a […]

W8LIW’s grabber on 30m is currently showing my “MV” beacon transmissions as well as the DFCW of VE1VDM (I presume) and the flying W of W1BW, as well as the faint sawtooth of WB3ANQ. I can’t spot myself on W1BW’s grabber at the moment: my ability to get into Concord, MA seems limited over the […]

Okay, I hadn’t been doing any WSPR beacon operations since before Thanksgiving (which was also before my new callsign) and I was kind of bored today, so I dug out my power supply, tuner and interface and set my computer beaconing again on 30m. It’s a combination beacon: using WSPR above 10.140100, and a visual […]

Well, this morning I decided I wanted to get the K1EL keyer that I put together mounted in a proper aluminum case. The sad thing was, I didn’t really pay enough attention to internal clearances, with the net result that I did a pretty crappy job. I’ll probably try again sometime soon, but in the […]

I subscribe to a number of different mailing lists related to radio topics. Something that has intrigued me for quite some time is VLF or Very Low Frequency radio, especially so-called Part 15 or “lowfer” operation. There has lately been some overlap with my interest in software defined radio. Some people have recognized that there […]