Show off your project in a clear top tin

We all want to package our electronics projects in some nice enclosure. An Altoids tin is often used - and I have used that a lot myself. But for slightly larger projects, the tin shown below is a better alternative. In addition it has a clear top, so displays can be viewed and the nice layout of your electronics can be admired. 

Worst snow winter since 1958 and an indoor Yagi antenna

Norway has had its fair share of precipitation this winter. Along the coast most of it has been in the form of rain. But that is different in the mountains. Our cabin at 800 m above sea level is now about to disappear in the snow and we can hardly see out of the windows anymore. This is a result of having had to shovel the snow off the roof three times so far this winter. And there is yet more to come.

They say that one has to go back to the winter of 1958 for more snow than we have had this winter, and we are still only in February. The snow has also given us an unexpected problem. Our digital TV signal is now gone.

Ultimate QRSS kits

I'm a great fan of Hans Summers (G0UPL) and his effort in launching kits for various slow speed modes. In fact I have all three generations of the Ultimate QRSS kits up and running. That includes the original single-band kit (30 m in my case, bottom in picture), as well as number 2 and 3, the multi-band kits.

The latest version, in the middle of the picture, has a nicer two line display, and it can also be fitted with a relay board. It makes it possible to jump between up to 6 different bands.

Single-lever and ultimatic adapter

Photo @LA3ZA 

Here's an adapter that emulates both a single-lever paddle mode and the ultimatic mode. It is meant to go between a dual-lever paddle and an iambic keyer. The adapter has been implemented in an AVR Butterfly in C and it is compatible with Morse keyers such as the one in the Elecraft K3 and the K1EL WKUSB. The single-lever emulation is probably the most novel part and it is meant to make it easier to practice single-lever keying on a dual-lever paddle.

Video of busy 70 cm ISM band due to car key fobs

The audio in particular should make it clear how busy the frequencies around 433.92 MHz are:

Data recorded from an RTL-SDR USB dongle with the SDR# program using the Apowersoft Free Online Screen Recorder.

Related posts:

• "Car keys in the 70 cm band" (with more documentation of hardware and software)
• "Not so busy 70 cm ISM band"

Not so busy 70 cm ISM band

Yesterday's post entitled "Car keys in the 70 cm band" showed a very busy band around 433.92 MHz with up to 10 simultaneous transmissions. That snapshot was taken on a Sunday afternoon at 16:32 local time. Here is a much less crowded snapshot taken with the USB SDR-RTL dongle under the same conditions as the previous blog post. The difference is that this is from late Monday night at 23:34 local time:

Press image for a larger view

There are only three bursts of about 1 second length here. This shows that the activity in the band varies a lot and in my mind strengthens the case for believing that the main contribution is from car keys. But of course, one cannot be certain without decoding the bursts. That is possible for weather stations, as shown by Gough Lui in the article "RTL-SDR: 433.92Mhz ASK/OOK Decoding of Various Devices with rtl_433". The bursts can easily be heard if the receiver is set for Wide FM, as shown in the settings of SDR# in the image above.

Thanks to all viewers who have made the former blog post the most popular on my blog for this week. Thanks also to the RTL-SDR blog which gave it publicity in the blog post "Looking at the 432 to 438 MHz ISM band".

Related posts:

• "Car keys in the 70 cm band"
• "Video of busy 70 cm ISM band due to car key fobs"

Car keys in the 70 cm band

The 70 cm amateur band covers from 432 to 438 MHz in Norway and radio amateurs have primary status. Secondary users are among others remote controls for keyless entry systems for cars since it is an ISM (Industrial, Scientific, Medical) band also.

I wanted to see how much traffic the secondary users generate. I used my RTL-SDR dongle with RTL2832U and R820T chips that I bought on Ebay for less than 10 US$ almost a year ago. The antenna was a roof mounted HL-B61N vertical (1.7 m long). This is the output of the SDR# program:

Press image for a larger view

It is clear that this band is pretty busy! No wonder that amateur repeaters have had to move their input frequency away from this frequency range. 

The waterfall covers 10-12 seconds and there are up to 10 transmissions simultaneously. The nominal frequency is 433.92 MHz and there are emissions from 433.75 - 434.05 MHz. I live in a suburban area with about 1 million people, but I imagine that I only pick up a small part of the remotes in this area since the car key transmitters are very weak. Anyway it demonstrates both the versatility of the cheap software defined receiver dongle, as well as how busy the band is. 

Related posts:

• "Not so busy 70 cm ISM band" showing the status on a late Monday night
• "Video of busy 70 cm ISM band due to car key fobs"

Clever K3 macro trick

Tonight I sat down to fiddle with the macros of my Elecraft K3. As I already use M1-M4 for CW memories, I only had the PF1 and PF2 buttons available.

It was the blog post "K-3 Rotating Macros" of W8TN that made me aware of a clever trick for using a macro to reprogram itself. This gives the possibility to have two rather than one function in the PF2 button. My need is for a button that can toggle between the typical pile-up functions Split+1 and Cleanup. In addition I have another macro that toggles speakers on and off.