Archive for April, 2017

A Couple of Interesting Software Defined Radios

April 3, 2017

For several years I have had a Perseus Software Defined Radio (SDR) manufactured by Microtelecom in Italy. The Perseus is an excellent radio and I have used it extensively for medium wave and long wave DXing. But it is not inexpensive.

There are other SDRs on the market at lower price points. I had not owned any of them until just recently.

The SDRplay has been popular since its introduction. A new version has recently been made available called the RSP2. The unit (including the SDRuno software) can be purchased for less than $200. A USB cable is required (not included) and you may need adapters for the antenna connectors. Details about the RSP2 are here:

http://www.sdrplay.com/rsp2/

The RTL-SDR dongle has been around for quite awhile. It was originally manufactured as a TV tuner. It was found that the I/Q data can be accessed directly, so the dongle can be used as an SDR. An overview is here:

http://www.rtl-sdr.com/about-rtl-sdr/

Earlier versions were only capable of reception on frequencies above 24 MHz. There is a new version called the “RTL-SDR blog V3” that allows reception of much lower frequencies. This web page describes how this is done with a V3 dongle, using the SDRsharp software:

http://www.rtl-sdr.com/rtl-sdr-blog-v-3-dongles-user-guide/

The RTL-SDR dongle is available for about $20. It is very small, with a USB connector on one end, and an antenna connector on the other.

Installing software and getting either of these SDRs running is not trivial but it is not difficult either. Readers should take a look at the respective web sites to understand the process. Among the various SDRs on the market today, there are a lot of variations in features available, and hence some SDRs may not work for a particular application. One thing for sure, there are SDRs available that provide a lot of capability for much less money than traditional hardware-only solutions.

Differential GPS (DGPS)

April 3, 2017

Long-time readers might remember me discussing listening to Non-Directional Beacons (NDBs) on the longwave band (frequencies below the AM broadcast band). A fairly recent addition to the inhabitants of longwave are the Differential GPS stations, which can be found between about 283.5 and 325 KHz. The Wikipedia page with background information is here:

https://en.wikipedia.org/wiki/Differential_GPS

As a digital signal, decoding software is required to be able to DX and log these stations. As luck would have it, Chris Smolinski of Black Cat Systems has written an excellent program called “Amalgamated DGPS” for Windows and Mac. It can be downloaded here:

http://www.blackcatsystems.com/software/dgps_decoding_software_sdr.html

The software can be run using real-time audio from a suitable longwave receiver (or an audio recording). It also functions taking an I/Q recording from a Software Defined Receiver (SDR). This is the way I use the program. I set up my Perseus SDR to record the entire DGPS range (283.5-325) for some period of time. This is an “I/Q” file. The software is then run using the I/Q file as input. It then lists the various DGPS stations it was able to decode.

For each station listed, make note of the “count”. Chris warns that the DGPS error detection protocol is not very robust, and false decodes are common. If the count is just 1, I would say it is fairly likely that a false decode has occurred.

 

 

Playoff Bound

April 3, 2017

The Blue Jackets clinched a playoff berth during March and were 10-6 during the month. But their offense has sputtered over the last couple weeks. So even with the beat goalie in the league, one wonders if they can make much of a run in the playoffs. A President’s Cup for the best record in the NHL regular season was not out of the question. But with last night’s 3-2 loss to the Capitals, Columbus has its first 3-game losing streak of the season. The Jackets are 6 points behind Washington with 4 games to go for both. But no matter what happens, this is the best season in franchise history for the Blue Jackets.

NCAA Women’s Tournament

April 3, 2017

Congratulations to South Carolina on their national championship. As a player, Dawn Staley went to three Final Fours but was never able to win it all. Now she has a championship as a coach. Mississippi State has a great team but I was not surprised at the outcome of last night’s game. With players like A’ja Wilson, Carolina is tall inside. Kentucky had absolutely no luck in three games against the Gamecocks, losing all three by wide margins. The Cats had a win in their meeting with MSU.

The UK women managed a #4 seed in the NCAA, so got to play their first and second round games at home in Memorial Coliseum. Ohio State, after losing early in the Big Ten Tournament, were a #5 seed. But the Bucks were placed in Lexington. In the first round, Kentucky edged Belmont and Ohio State beat Western Kentucky to get up a second round matchup between the Cats and the Bucks. OSU won 82-68 to move on to the regionals in Rupp Arena in Lexington. The Buckeyes were no match for #1 seed Notre Dame and lost in a rout.

I was as surprised as anybody at Mississippi State’s upset win over Connecticut in the national semifinals. Gino Auriema’s smile after the game reminded me of the Facebook meme: “Don’t cry because it ended, smile because it happened”. The Huskies will continue to be a dominant force in women’s college basketball for years to come.

Wrapping Up March

April 2, 2017

You would think with all the stuff that went on in March, I’d be able to keep up with this blog. But, nooooooooo. I guess I was too busy doing stuff to write about stuff. In any event, in the next few posts I’ll try to get caught up, probably only to get behind again. And so it goes :-).

It’s been a great NCAA Tournament as usual. Despite all the upsets, the championship game tomorrow night will feature two #1 seeds. I had been expecting that Mark Few and Gonzaga would eventually break through and make a Final Four. They have a good enough team to win it all. It would be funny if North Carolina finished runner up for two years in a row. But I really like their inside game, and they could easily win tomorrow.

Kentucky had a lot of momentum after winning the SEC Tournament, and managed to beat UCLA in a regional semifinal, avenging a regular season loss in Rupp Arena. The Cats gave North Carolina a good game in the regional finals, but came up short.