Magnetic Loop Antennas

These look pretty interesting. I have heard of them beofore - you can make a physically small antenna for the low bands, but they also work well for all HF bands. Different designs yield different levels of efficiency and frequency coverage.

Check out these sites for more:
http://www.alexloop.com/
http://www.standpipe.com/w2bri/

AA5TB has a nice list of a bunch of other sites at the bottom of his:
http://www.aa5tb.com/loop.html

RFSpace SDR-IQ and FT-2000

If you read my blog you have seen my posts in the past on the FT-2000 and other higher-end radios. The FT-2000 is probably the next radio I will get. It seems all of the newer "higher end" radios all have, or have the provisions of, spectrum scopes - very useful tools for scanning the bands. The IC-756proIII has one built in (probably the most popular full spectrum scope radio there is right now), as well as the IC-7700 and IC-7800, with the IC-7600 now taking the IC-756proIII to a whole new level. Yaesu seems to be a bit behind in the eye-candy department. They seem a bit more in-tune with the knobs, buttons, and meters - what we adjust to make the radio do what we want it to do. Take a look at the FT-2000 and FTdx9000 series radios. The only one of those that has a spectrum scope built in is the FTdx9000D. All the others have the option of the DMU-2000 (for the FT-2000 series, and 950 as well) or the addition of other accessories to the other FTdx9000 series radios.

To make a spectrum scope work, the right way where an entire band can be seen on the screen, not the passband (the RF that is narrowed down to just what you are listening to after the filtering in the IF stages), a very wide RF signal has to be fed in for the device doing the processing to read. If the information isn't there you can't see what is there. The object of a spectrum scope is to see where signals are within a band - all up and down the band, well outside the range that any radio can hear in it's passband.

Most radios have a 15-20kHz front end on them. If the first IF is forwarded on to the spectrum scope's processor you are limited to 15-20kHz of spectrum - not much, considering an FM signal is about 12-15kHz wide alone. So the raw RF has to be analyzed by the processor, pre-stage one filtering. This allows the computer to see everything, filter it to whatever the user specifies, and centers it on the bandwidth selected based on the frequency of the VFO.

Yaesu has a device to do just this - the DMU-2000, which is the same processor from the FTdx9000 series only in a stand-alone box that works with the FT-2000 and FT-950 series. However, as anyone can see watching the scope, the processing speed is pretty slow. The scope doesn't move fluidly - it jumps around and when you scroll the band there is a bit of lag between the spectrum display and the frequency the VFO is on. Watch any of the YouTube videos on the FT-2000 with the DMU-2000 display and you'll see what I mean.

RFSpace has a device called the SDR-IQ that does what the DMU-2000 does - taking raw RF and letting your computer analyze it and display it - only, it does it MUCH faster. Watch the video on the SDR-IQ with the FT-2000, it really is pretty spectacular. The display tracks the VFO very quickly. There is no lag time and it is very smooth, unlike the DMU-2000.

The FT-2000 is most definitely still on my radar - as well as the add-on devices for the spectrum scope. I am not sure if the DMU-2000 is worth the $$ for what it does. It does a lot, but there seems to be some debate with the FT-2000 community as to how good of a unit it is. The quality, speed, and user interface seem to be lacking but it has a lot of features. The SDR-IQ is obviously a higher quality unit, but it is only a signal display device in this case (either a spectrum scope or waterfall). It doesn't have the other applications that the DMU-2000 does, and it doesn't allow for compact flash storage of the radio's parameters.

Note: the SDR-IQ is a software defined HF receiver. It can run as a stand-alone receiver, but in the context of my analysis here I am looking at it as a tracking panoramic adapter for the FT-2000, bringing the spectrum scope to the rig in place of the DMU-2000.

Thoughts on Digital Modes and Computer Applications

I haven't run digital modes for over a year now. I just got away from having a computer along with the radios. It just seems so much easier to run CW or SSB with a key or a microphone than to wire up a computer to a radio. However, I wanted to give PSK31 a try again. I got a new laptop computer for my birthday last summer and have not run any ham radio applications on it what so ever since.

My RigBlaster Plus came with a CD for digital mode software and other applications. However I got my RigBlaster about 5-6 years ago so the software on the CD is surely out-dated. Rex, W8WZZ, was using DigiPan on PSK31 during Field Day - and apparently it was a brand new version (to me anyway). So I went online and downloaded the new version of DigiPan and tried it out.

My laptop (a Toshiba) doesn't have a COM port on it (the old DB-9). All it has are USB ports. My GPS and my RigBlaster (as well as my TS-2000's data port) are all DB-9's. So I got a USB-Serial port adapter at Radio Shack before we went to Canada so I could use my new computer with the mapping software. It wasn't straight forward to get it set up, but I got it working and was able to directly track my location on the computer in real time.

So back to the RigBlaster. I had to jump through the same hoops getting this USB-Serial adapter to run properly with it. I had a few more bugs to work out with the sound card and the cable from the RigBlaster to the radio, but I was able to get it to work.

I have to say, it felt pretty neat re-visiting the waterfall display and yellow tracers! I worked 20m for a bit and had a lot of fun. I have only worked one station so far, but I know I can get on the mode again. That's pretty cool!

I also loaded a few other applications - WSJT and WinRad. I used to work Meteor Scatter on 6 and 2 meters with FSK441 when I was back at my Dad's house (I had beam antennas on a rotator up on the roof). That was over three years ago now. Anyhow, I downloaded the latest WSJT version to see what was new over there. The modes list on there is about three times as long as I remember - I guess there has been a lot of experimentation (or there is a lot of experimentation) going on!

I still don't have WinRad figured out yet. I saw this was able to be used with the SDR-IQ from RFSpace and is a free program so I figured I would see what it was all about. To get the most out of this program you need to feed an IF signal in to it (what the SDR-IQ does, in conjunction with the proper interface to your radio). Basically, it turns the computer in to your receiver - the radio still works how it works but the RF that goes through the regular radio is split to the computer as well so you can monitor the RF (such as on a waterfall display, spectrum scope, etc).

I don't have any way to feed an IF signal in to my computer, but I can run audio in. The waterfall display is pretty sophisticated and I would be curious to play around with it to see what all it can do. There is something intriguing about watching all the signals flow on a display and move around as you tune the bands!

To that note, if anyone knows how to get WinRad to read the straight audio input without it's radio simulation or whatever it does send me a message. I can't seem to figure out how to turn that off. The only way I can get anything to go through the WinRad processing is if I hit the "start" button, but that activates the radio simulation. My audio is fed on top of it.

Ham Radio Deluxe is another application I downloaded. I used this to control my TS-2000 in the past, but that was on a couple other computers. The new laptop doesn't have it so I figured I would put it on. This program also allows you to log and there is a really handy DX spotting feature (when connected to the Internet). The spotting feature is probably why I used the program most in the past - you can watch specific bands individually or all bands and as soon as a station is spotted it shows up on your screen. All you have to do is click on the spot and the program (which is a computer control program for radios by design) flips your radio to the exact frequency, no VFO knob to scroll or buttons to push!

For some reason my USB-Serial port adapter is giving me fits with Ham Radio Deluxe. There is a start up screen you get for activating your radio. The computer has to read the operational data from the radio (frequency, mode, user settings, etc) and then once that happens the computer and radio can talk to each other. My first problem was getting the COM port that my adapter was on to show up in the program. Somehow when I closed the program and re-booted it the rest of my COM ports activated in the program so I was able to select the one I needed. However, I can't get the computer to read my radio's initial data. The PC indicator activates on my radio's display saying there is some type of connection/signal, but I can't get the computer to read the data. I tried calibrating the data rate of all three devices (the radio, adapter, and program) but that didn't work. I tried automatically detecting the settings and that didn't work. So I don't know. If any of you have some ideas, fire away! Otherwise I will play around with it some more and see what happens. It would be nice if the computer just had a plain old DB-9!