During November, we suffered loop array wind damage. Fortunately, repairs are pretty easy with a 3D printer on hand. Well, it had to happen sooner or later. During mid-November, both loops in my wideband loop array were damaged during a strong wind storm here in Calgary. You may recall that I have two switchable loops arrayed on a 100 foot baseline. Together with diversity reception, my array does a wonderful job with beamforming and noise cancellation. You can check my previous articles for details. My loops are made with lightweight aluminum core PEX, and mounted with 3D printed structures ..read more

Recently, I decided to repurpose an old laptop to run Linux, mainly to experiment with SDRconnect. Here is how that went. So, I am a Windows guy who has dabbled in Linux over the years, mostly running Ubuntu in a Virtual Machine. So, I installed SDRconnect in an Ubuntu VM, but for some reason performance was terrible. Lots of noise was added to the signal. I suspect the VM was not processing the USB data cleanly. Then, I tried a different approach. Most of us probably have an old computer lying around unused. I discovered, in my wine room of all places, an old Toshiba laptop with Windows 10 ..read more

After much anticipation, SDRplay released SDRconnect Preview 1 on August 10, 2023. It looks great and works well cross platform. Windows, Linux and Macintosh OS are all supported by this new radio control software from SDRplay. All current SDRplay RSP gear is supported, including diversity reception on RSPduo. I found installation easy and you are up and running quickly without “reading the manual”. So, yes, SDRconnect Preview 1 has limited functionality at this stage of release. But, I found that most of the basics are there. You can enjoy using it right now. Developing a cross-platform real ..read more

Wireless intercept deception played a critical role in most military operations. In doing so, combatants needed to fool sophisticated traffic analysis.  Both Allies and Axis were really good at traffic analysis of intercepted signals. So good, in fact, that any serious operations needed to include wireless intercept deception. Basically, deny the enemy knowledge of your real intentions; deceive them into making false assumptions. For example, Operation Overlord contained massive, multi-faceted deception. This included creation of fake armies complete with inflatable tanks, and fictional ..read more

Every good story needs a hero. Here are my picks for the WW2 Wireless Intercept Heroes you should know about.  In my mind, all of the men and women who did wireless intercept during World War  2 are heroes. But I will mention a few individuals who stood out when I was researching this series. For my top hero, I pick Sir Robert Watson-Watt for his enormous contribution to the war effort. Some have called him the “father of radar”. To me, however, he was a dedicated boffin in the right place at the right time. Born in Scotland in 1892, Watt found himself working at the London Met Offi ..read more

What began as a search for Nikola Tesla’s idea for a death ray led to the very practical creation of Chain Home radar system and victory in the Battle of Britain.  For the most part, radar is a form of wireless intercept. You force a metal object to transmit a signal. Actually, to reflect a signal on a frequency of your choosing. In 1935, some British scientists sent a memo to government outlining how this could be done. Fearing the worst, government established a crash program. Britain’s Chain Home radar system was built quickly and operating by 1938. Although quite innovative, Chain Ho ..read more

Wireless intercept fighting U-boats won the Battle of the Atlantic. In addition to Ultra, tactical advantage came from Huff Duff.  Oceans are huge. Germany used a lot of radio to organize its U-boats over great distances. At sea, individual submarines announced convoy locations and coordinated attacks over wireless. All of these signals were prime targets for direction finding. Shore-based fixed DF stations and Ultra did a good job of finding U-boats in general. Convoys were re-routed in real time. However, ship-borne DF was needed to get specific locations and attack formations. This loc ..read more

High frequency direction finding, or Huff-Duff was used to find locations of enemy transmitters in the field, on land, and especially at sea. This was a global effort.  So far we have talked about collecting radio intercepts to be decoded, and also using those intercepts for traffic analysis. The next piece of the puzzle is finding out where the signal is coming from. Signals intelligence made extensive use of high frequency direction finding during WW2. Referred to as HF/DF, or colloquially as Huff-Duff, it made a critical contribution. Direction finding provides a bearing but not a loca ..read more

While code breaking is spectacular, radio traffic analysis was the real meat and potatoes of signals intelligence from WW2 wireless intercept.  Even without understanding or decoding the message content, the silent listeners obtained staggering amounts of actionable information from the flow of signals themselves. It’s called radio traffic analysis or T/A and has two components. First, what party is sending the signal and to whom? What is the frequency and the call sign? Where is the message coming from and where is the destination? Are there code names for participants or locations? Are ..read more

Although most hams joined the forces, several thousand stayed home doing civilian intercept. In Britain they were volunteers. In the U.S. they worked for the FCC.  When the war started, Britain’s MI6 ran the Radio Security Service. Its original purpose was to intercept and find transmissions from enemy agents in the homeland. RSS pretty much shut down spy operations, in many cases turning captured spies into double agents by MI5. Radio Security Service not only did civilian intercept, it used more than 1500 ham radio operators as volunteers. With the cooperation of Radio Society of Great ..read more