AmateurRadio.com

I hadn’t put the receiver on 145.825 and monitored the packet transmissions from the ISS digipeater for a while. Nice to do so over the last couple of days and see plenty of stations plotted on the map.

I haven’t been in shack at the right time to press the transmit button – but it’s just interesting to see what’s been heard

Gear is the FT8900 / V2000 vertical – UZ7HO soundcard modem software/UISS software

Tim Kirby, G4VXE, is a regular contributor to AmateurRadio.com and writes from Oxfordshire, England. Contact him at [email protected].

We have started another intermediate class both in class and distance learning. This course is primarily run on Edmodo. We have run a couple of classes on Edmodo and we think we have the concept correct now. So we have our weekly quizzes set and our 3 week homework assignments all loaded and ready to go.

In class students are also welcomed to join the distance learning students so missing a lesson is no longer such an issue.

Over the coming weeks I will be creating some companion videos showcasing the practical elements of our in lesson activities.

So far we have 5 in class and around 30 distance learning joining us for the next 10 weeks.

Dan Trudgian, MØTGN, is a regular contributor to AmateurRadio.com and writes from Wiltshire, England. He's a radio nut, IT guru, general good guy and an all round good egg. Contact him him here.

It’s always easy to point a finger at others when you encounter noise while scanning the bands. More than often it is yourself who has to take the blame. In my case the switching power supply from my shack laptop is producing a lot of noise and artifacts, especially below 7 MHz. For a long time I had the plan to operate the laptop from my linear power supply and recently I got serious about it. A DC-DC step-up converter was bought for a mere US$7 and the following video shows initial results are very encouraging. The unit runs very cool so I am going to box it up and see if it can handle long operating periods.

Next up: isolating the USB connection. Stay tuned.

Hans "Fong" van den Boogert, BX2ABT, is a regular contributor to AmateurRadio.com and writes from Taiwan. Contact him at [email protected].

 

Earlier this week the Wall Street Journal published an article about the growing prevalence of RFI from unlikely sources.  They quoted Tom Thompson, WØIVJ, of Boulder, Colorado:

Radio hobbyist Tom Thompson of Boulder, Colo., last year tracked a signal using a homemade contraption. After knocking on the suspect’s door, he traced it to ballasts on marijuana grow-room lights. He says he built a filter that the grower agreed to use.

Tom, a retired NOAA electronic engineer, created an entire web page devoted to the grow light ballast filters. According to his page, these ballasts are switching power supplies for high-pressure sodium or metal-halide lamps.

He goes on to describe the problem in good detail:

Typically the light fixture is removed from the ballast by about 25 to 30 feet.  Since this length is about a 1/4 wavelength on 40 meters, it makes a good “antenna” for 40 meters so the RFI may be strongest on 40.  I have heard radiations from these systems up to about 1/2 mile away.  Also, since the “antenna” is so low to the ground, the RFI is mostly vertically polarized which is important when tracking it down.

Check out his page to see how he built a filter that he says reduces the RFI by about 30dB. That’s some good ol’ ham ingenuity!

Matt Thomas, W1MST, is the managing editor of AmateurRadio.com. Contact him at [email protected].

It's been a while since I've had the time to sit down and write a few lines. My recent work and personal schedule has looked like a blackout bingo game. When work interferes with play, that's serious. That said, I have been able to do a few things around the shack. I've been clearing out some of the surplus of QRP radios that have accumulated over the years to make room for more QRP radios. It is, after all, the circle of life isn't it. Buy it, play with it, look at it, sell it and then buy something else to start the cycle over again.

I've also changed up my QRO line-up. I have the FT-5000DX which is a wonderful radio. It does however take up a fair amount of real estate on my, not-so-big, desk. Along with VL-1000 amp, I don't have much room left over. So, I am sending the FT-5000 to my ranch station and replacing it at the home shack with a K3. Not a bad trade. I just received the K3 and am getting comfortable with it. Having owned a KX3 for while, the learning curve is not too steep. There is another agenda here and that is I want to be able to remote into my home station when away and Elecraft has an elegant solution for that. They build a K3/0 which looks just like the K3 but without the TX and RX circuitry. So when remote, you have the same front end to play with. Plug in your key, link up, spin the knobs and away you go. At least that's the theory. I will be setting this up soon and I will report on the progress.

So the circle of life is always with us, which makes life interesting.
Mike Crownover, AD5A, is a regular contributor to AmateurRadio.com and writes from Texas, USA. Contact him at [email protected].

AmateurLogic.TV Episode 64 is now available for download.

Peter sends Tommy and George some Australian treats. See how they react to Vegemite.
George has an introduction into cheaply receiving and decoding digital signals.
Peter brings us the Making of AmateurLogic Downunder.
Tommy builds an Arduino Heads-Up display for use with rigs that have Cat ports and more.

1:16:45 recorded live before an Internet audience.

Download

View in web browser: YouTube

George Thomas, W5JDX, is co-host of AmateurLogic.TV, an original amateur radio video program hosted by George Thomas (W5JDX), Tommy Martin (N5ZNO), Peter Berrett (VK3PB), and Emile Diodene (KE5QKR). Contact him at [email protected].