brainwagon

Well, I was bored, and it was getting close to midnight. There was nothing really going on on any of the amateur radio bands, so I got to thinking. Light travels about 186,000 miles per second, or about 186 miles per ms. On 10Mhz, NIST broadcasts a standard time signal from stations in Colorado, and […]

Ordered a new Collins 500hz filter for my FT-817 from W4RT, and installed it (really simple, remove some screws, disconnect speaker, plug in the module in the obvious place, reconnect speaker and screws and you are done). It really does help with cw and digital. As an example, this morning I tuned down around 7.039 […]

Somebody is sending out a CQ. I just noticed it at the end of a recording I did, but he’s retransmitting again now. I’ll let the recording go for a while, then try to figure out who it is. Until then: Addendum: It was WB5FKC.

Well, I woke up this morning, kind of bleary eyed, and decided to see if I could reach any of the other QRSS grabbers during the morning hours. VE1VDM’s grabber is apparently only receiving his transmit signal, but W1BW was up and running… There I am, drifting up in frequency across the bottom. Copy is […]

Well, I was experimenting a bit. I dusted off my QRSS3 iTunes beacon idea, and set it going. VE1VDM had his “big ears” grabber going, so I started watching it. He’s in grid FN85ki, which is roughly a 3000 mile path. To help assure success, I was sending 5 watts (horrendous, I know, but I […]

I was monitoring the 30m PSK31 subband this evening, and it seemed to be fairly quiet and also picking up some pretty good DX. I heard WP3UX and WP4U chatting with ZL4AS. The first two stations are in Puerto Rico, about 3600 miles away, and the ZL is about 7000 miles away. I think that […]

Sven Grahn’s Space Tracking Notes talks about his efforts in using radio to track satellites. There is all sorts of really good stuff in here, a lot of it having to do with tracking the secret launches of Russian satellites during the Cold War. Very, very neat stuff.

Yesterday, I was playing with WebSDR, an awesome software defined radio that you can access from the web, and I noticed that there was a Morse signal on the 40m band that just repeated “D” endlessly, and right next door, another that repeated “C” endlessly. A bit of digging revealed that these were “letter beacons”, […]

Tonight was a momentous occasion. Using 5w of power into a low end fed antenna, I managed to get two contacts. The first was Chuck, KB7OGE on 30m, and the second was Don, W7DTG via 40m. It’s very odd. I can’t seem to hit hams who are just a few miles from here (probably because […]

While mucking around last night, I ended up asking myself how i could find out what the attenuation of the TV antennas atop Sutro Tower would be. While trying to answer this question, I found out about Splat! SPLAT! A Terrestrial RF Path Analysis Application For Linux/Unix I haven’t worked out the attenuation from Sutro […]

I need to remember to bookmark DJ1YFK’s website. He’s a regular on the #hamradio irc channel, and he has a bunch of nifty stuff on his website. I was most interested in his experiments with simulated Morse at various noise levels, which duplicate some experiments I’ve been tinkering with for the last few days. DJ1YFK […]

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 […]

I have been monitoring 30m to try to detect some of those MEPT (Manned Experimental Propagation Transmitters) that I wrote about a few weeks ago, without any real luck. I’ll be trying again this weekend, but since I was bored, I decided to tune down to 10.000 Mhz and try receiving the time signal. It’s […]

Well, I decided to try again to record some of the beacons that are on 30m. I recorded 1 hour of what sounds like white noise starting on July 5 around 18:30 UTC, and then ran it through an FFT and mapped out the frequency ranges that represent 10.14000 to 10.140200 Mhz. Here’s a processed […]

I’ve been bitten by the QRPP/QRSS bug, and am considering a project where I build a MEPT (that stands for Manned Experimental Propagation Transmitter, apparently), which is a simple beacon transmitter that many people are using to experiment with on the 30m band. QRSS activity is usually in the range from 10.140 to 10.1401 (yes, […]