Software Defined radio - CHEAP

Jan 22, 2008
423
Catalina 30 Mandeville, La.
In true ham fashion, where we are typically so tight ( money wise), that we squeak when we walk, I found a really neat little device that opens many SDR doors, for next to nothing, relatively. My primary HF rig at home is a Yaesu FT-950. I've been looking at the DMU-2000 from yaesu for the panadapter features like bandscope & waterfall display. The DMU-2000 provides that, plus waveform visualization, swr, & other features, I'm not as interested in, and costs about $1200. The device is this software defined receiver that I found on Amazon. It's actually sold as an over the air TV receiver. This is about the size of a large USB memory stick and plugs into a PC USB port. It has an antenna connection and includes a small antenna. This thing operates from like 24MHz through 1700MHz. My FT-950 utilizes a 65.45MHz IF and includes a simple TMP coax connection on the IF board for the DMU-2000 connections. 65.45MHz is within the range of the device and when combined with free software, I can get an effective panadapter with some rig control through the standard CAT interface as well. I just ordered one and am sourcing some cables to interface it to the radio. I originally put two in my cart, but decided I would do some testing before I wasted another $10 on a second one.

Fascinated with this SDR, I began searching for more info and found some other interesting projects, such as AIS receiver that utilizes openCPN for plotting. Might be the absolute cheapest way to get AIS. Here's a link for more info on the AIS utilization.

I thought you guys might be interested in this and would like to hear your opinions.
 
Feb 17, 2006
5,102
Lancer 27PS MCB Camp Pendleton KF6BL
Thanks Forrest. The AIS stuff would interest me. Will look into it. The link is not working. I will try later.
 
Jan 22, 2008
423
Catalina 30 Mandeville, La.
I cancelled my ARRL membership a few years ago. The QST's were piling up unopened. I know these things have been around for some time, but it's new to me. I'm having the interface cable made up and should be up and running within a week or so. Looking forward to playing around with it and hope it's not a total piece of crap. But I'm only in it for about $25 total.

The links work for me Brian. Here's the actual URL's below:

http://www.amazon.com/RTL-SDR-RTL28...e=UTF8&qid=1397662284&sr=8-1&keywords=rtl-sdr

http://www.rtl-sdr.com/category/marine/

http://www.hdsdr.de/index.html
 
Feb 17, 2006
5,102
Lancer 27PS MCB Camp Pendleton KF6BL
Yes, it is working now. Thanks.

I was involved, all be it on the test side, in SDR several years ago. It was on military satellite radios and it was very interesting. I always thought it would never work, but I was wrong. Now it is really interesting how it has moved into the ham community.
 
Mar 12, 2008
557
Jeanneau 49 DS San Pedro, CA
Very interesting. I passed the info along to some friends cruising in Malaysia right now. I had helped them with setting up a GPS dongle so they could use their computer as a backup chartplotter, but didn't have a way to get AIS onto the charting software. They use OpenCPN to all they route planning. This might be the ansew for them.
 
Feb 17, 2006
5,102
Lancer 27PS MCB Camp Pendleton KF6BL
I looked at the site and am a little disappointed in the abstract use of SDR (Software Defined Radio). To me, this is not SDR but just a GUI for use in tandem with radios. SDR are in fact real radios that have more functions controlled by embedded software and less hardware. SDR is not a graphical user interface to the radio but the radio itself.

I am sure that others may disagree. However, having worked on "real" military satellite SDR platforms, this page does not even closely represent what SDR is all about.
 
Jan 22, 2008
423
Catalina 30 Mandeville, La.
Brian, your definition is pretty narrow. All SDR's that I'm aware of have some degree of actual radio hardware. The device I pointed out is a basic wide band radio receiver. What is done with the signals it receives is defined by the software you couple with it. Most military or satellite radios are specialized, narrow use devices that lend themselves to embedded software well. The RTL dongle is a receiver with embedded software specifically for decoding over the air television. It's designed for asian television standards and that part of it is useless here. What is useful is the raw data from the wide band receiver can be accessed and used by user defined software. In this mode, it will not demodulate anything by itself. This is where the SDR part comes in. It's not a high grade receiver by any means, but it's only $10 and suitable (performance-wise) for AIS, or in my case, a panadapter bandscope. The fact that it is so cheap is what is driving so many people to create software for every use imaginable inside the bandwidth. It can't be all of that with just an interface.
 
Feb 17, 2006
5,102
Lancer 27PS MCB Camp Pendleton KF6BL
Yeah, I guess my expectations were a wee bit too high. LOL
 
Jan 22, 2008
423
Catalina 30 Mandeville, La.
I received my interface cable this week and have setup the dongle as a panadapter on my FT-950. I'm using the free hdsdr program that has the options of sync'ng to the IF and controlling the rig through the regular CAT control via serial connection. I'm still poking around with the software, mostly using it as a receiver. I can can set it up to view an entire band while operating the radio independently if I want. I can quickly tune to a signal on the scope or waterfall just by clicking it. The video below describes what I'm doing with it, except he's using an FT-857. I see myself using it primarily as a bandscope, but it could easily be used as a second receiver if needed. I can see myself operating PSK on the low end of 20 meters using the rig's receiver, while simultaneously monitoring a SSB net. Others who operate split freq's may see some benefit, but that's not really my thing. Anyway, It works fantastic for what I wanted, and cost me about $30 total. I will be ordering a couple more of these to play around with.

http://youtu.be/tshlXgarnBQ
 
Feb 17, 2006
5,102
Lancer 27PS MCB Camp Pendleton KF6BL
Thanks Forrest for that information. Sounds like you are going to have a blast with that software package. I was using a data package some time ago that had the waterfall feature. It was very easy to visually see where data was and just click on it. Now that I find convenient. If you get the AIS version let us know how it works.

While I was in Afghanistan I was using a spectrum analyzer to track drifting carriers on a satellite. It also had a waterfall function that made it easier to see anomalies in the carriers.