Sunday, March 1, 2015

Software Defined Radio FUN!

How technology has changed. It was not too long ago that at work I used a spectrum analyzer, O Scope, recorder, sonograph, high end receiver, simple computer, converters etc coupled to a rhombic antenna.... All in the name of Signals Analysis.

Now I can do all that and more from home. I recently picked up a NooElec R820T2 & DVB-T NESDR Mini 2 dongle from Amazon like this one.

It is not exactly plug and play. After not being able to get it to work I found and the read the instructions which I linked here.

After reading and installing everything correctly it worked great. For an antenna I have it hooked to my scanner discone which covers the freq range of the dongle (24 MHZ to 1.7 GHZ). Now I have the functionality of an analyst station in the ham shack for around 20 dollars.

If you want to learn more here are a few good resources.
RTL-SDR Website
NooElec website

The dongle is slightly bigger than a USB Stick

Antenna Port

Screen Shot, I am listening to a weather broadcast

I was not sure how useful this would be and thought if it does not work like I want no big deal. I was pleasantly surprised and have had fun listening to the spectrum I do not normally monitor. I know the software is very capable and need to read about it more and play with the settings.

Here is a youtube that I found useful when researching this particular dongle.

72 Frank

Sunday, February 22, 2015

End of an Era

The videos near the end of this post highlight the end of an era. An era that not a lot of people know about. The AN/FLR-9 or Elephant Cage (called that due to its size) is a HF Rombic Antenna that was used exclusively by the Electronic Security Command (what it was called when I served) in its mission to provide national and tactical level Signals Intelligence or SIGINT. Also, during my time, the antenna was coupled to the R-390 receivers and later the RACALs. Before my time the R-388 was the mainstay receiver and I have one in service in my shack that I use very often. 

The antenna array is composed of three concentric rings of antenna elements. Each ring of elements receives RF signals for an assigned portion of the 1.5 to 30-MHz radio spectrum. The outer ring normally covers the 2 to 6-MHz range (band A), but also provides reduced coverage down to 1.5 MHz. The center ring covers the 6 to 18-MHz range (band B) and the inner ring covers the 18 to 30-MHz range (band C). Band A contains 48 sleeve monopole elements spaced 78.4 feet apart (7.5 degrees). Band B contains 96 sleeve monopole elements spaced 37.5 feet (11.43 m) apart (3.75 degrees). Band C contains 48 antenna elements mounted on wooden structures placed in a circle around the central building. Bands A and B elements are vertically polarized. Band C elements consist of two horizontally polarized dipole antenna subelements electrically tied together, and positioned one above the other."

The array is centered on a ground screen 1,443 feet in diameter. The arrangement permits accurate direction finding of signals from up to 4000 nautical miles away.

FLR-9s were constructed at the following places:

Augsburg, Germany

Chicksands, UK

Clark AB, PI

Elmendorf, Alaska

Karamursel, Turkey

Udon, Thani Province, Thailand

Misawa AB, Japan

San Vito, Italy

The dismantling of the FLR-9 at Misawa is on-going and due to be completed this year (2015). The last AN/FLR-9 in existence is at Elmendorf AFB Alaska. 

Enough distractions, I need to complete a couple of End Fed HF antenna designs for portable use.


Saturday, February 21, 2015

TI9/3Z9DX in the log

I worked V31AT on 10 meters and a few minutes later I got TI9/3Z9DX on 12 meters. It took me two calls for V31AT and just one for the Cocos Island DX expedition which surprised me due to the mild pileup. I was using 5 watts to a dipole up about 20 feet but I had an unfair advantage over all the other callers. I installed and was using the second receiver in the K3 and it was super easy to find his listening freq. 
Confirming my callsign in the on-line logbook for TI9/3Z9DX

Unrelated video

The United States Air Force Thunderbirds

United States Air Force. Second to None.

Monday, February 16, 2015

Snow on Presidents Day

Lynn and I both had off for Presidents Day but the weather pretty much kept us inside. On Friday I was able to install Lynn's new 2 meter in her car (IC-880) and today I bought a RJ45 female to female connector and 3 feet of ethernet cable to finish that installation. I still need to clean up the wires a bit but it is installed and working.

I also installed the second receiver in the K3 but today was the first time I played with it. I think this was one of the best upgrades I did. I love listening to both receivers t the same time.

With the weather today I wanted to re-package a few projects that I have been working on. First up was the NEScaf which is a Switched Capacitive Audio Filter. I bought this specifically for use with the HW-7 and now the HW-8 in the field. I noticed on the NEScaf link that they are out of this kit. It is really a cool kit and works very well.

I found the tin at REI, I was going to mount the battery on the inside because there is enough room but decided to put a power jack on the outside making it easier to change out when needed.

NEScaf Filter
This repackage went fairly quickly since there was a lot of room to work with. Mister Mann decided he would rather play in the dirt than help me.

Mister Mann checking the underside of the deck
Next up was the Rockmite 30 Meter transceiver. I had this mounted in an Altoids Tin but wanted to do a cleaner job and also wanted to use the unique tin I picked up while on a SOTA activation in Estes Park Colorado.
30 meter Rockmite II
I like the Rockmites because they are simple and can go together in an afternoon. Great kits to learn on or just have fun with. Our baby cat Maura decided it was better to watch "cat TV" or look out the window than help with this one. She did check in on me in between naps.

The final one was the 200Hz HighPerMite audio filter. I really like this one offered by the 4 State QRP Group. Fun and easy to build and very practical with the Rockmites.

I think the next one will be the 3 band Steve Weber designed MTR. While the case that came with it is compact and strong there is just something about doing you own enclosure. I found a tin that is slightly bigger than a Altoids Tin that will be a perfect fit. I am not sure if I will do this one as I may sell off this radio. I just do not use it at all and actually bought it for someone else that does not want it.

Our older cat is in her 20th year and was wondering where her Dental Mints went to.

I do have one of the early Rockmite cases and really like it. It holds my 20 meter Rockmite and is the one I used for the Rockmite Challenge in 2013 on Mount Herman. It really was a lot of fun to run a pileup putting out 200 milliwatts to a simple wire antenna. Here is a picture of the 20 meter Rockmite along with my favorite QRP SOTA radio, the Steve Weber designed MTR dual band (30 and 20 meters).

20 Meter Rockmite on the left and 20/30 Meter MTR on the right
Of note Lynn and I did a drive up SOTA activation on Valentines Day on 10808 near Victor Colorado. We got a cabin where we got married at (near that area) and had an enjoyable time relaxing. It was nice to get out in 4 feet of snow and work the SSB and CW pileups with Lynn's KX3.

72, Frank, K0JQZ

Monday, February 9, 2015

K1N is in the Log!

Finally, after a week of trying to get K1N and jumping into the madness I was finally able to get them. I was listening off and on all day and I could hear K1N on 40 meters fairly well in the evening and tried for at least an hour straight to get them. Even with the P3 I could never really locate their listening freq.  This was frustrating and the pileup was tremendous, the worse I have ever heard.

There were a lot of people calling on his transmit freq but I bet most people did not realize they where not split. I am guilty of this as well from time to time when I had a Ten Tec Omni 6 and it was very embarrassing when it happened. With the K3 and P3 those guessing days are gone and I now actually prefer to work DX split. It gives my 5 watts an advantage.

I noticed a spot that had K1N on 20 meters and I went there and the pileup was just starting. I easily found their listening freq, put out my call and they came back after my first call. I looked over at Mister Mann and he did not seem very impressed. I was ecstatic!

Mister Mann was not impressed and wanted more cat nip

K0JQZ is in the K1N Log!
I was using 5 watts to a Dipole no more than 20 feet high. This was an example of luck over skill but I will take it.