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I’ve been considering getting a Raspberry Pi for awhile.  Several folks have asked me if I would port my Arduino Keyer code to it.  So I decided to take the plunge and acquire a Pi from Newark / Element 14, along with some “fixins”.  I got the Model A Pi, along with a WiFi dongle, and a cute little enclosure.

Big Things Come in Small Packages

I didn’t realize just how small the Pi was until I held one in my hand.  It’s just amazing this is a full blown computer.  It’s quite a leap from the VIC 20, the first computer I used 30 years ago as a teenager.

Raspbian Installation

The Raspberry Pi was surprisingly easy to fire up.  I bought a 16 GB SD card locally and burned a copy or Raspian on it.  After plumbing up a monitor to the HDMI port and connecting a USB keyboard and mouse, the unit booted right up, displaying messages familiar to anyone who runs Linux.  A few minutes later I entered startx and I was in XWindows.  Of course I just had to bring up a terminal window and verify this was really a ‘nix box and run top.

Nifty Little Pi Enclosure

Now that I have my Pi humming away, what projects should I do?  As I’ve mentioned a few folks have inquired about porting my keyer code to the Pi.  Googling around I found someone has ported the Wiring development platform , which is the basis for the Arduino environment, to the Raspberry Pi and aptly called it Wiring Pi.  Naturally it’s not 100% compatible and it’s not as easy as just plugging in the Arduino IDE and uploading compiled code.  I’m debating whether to take this approach of getting the keyer code to run under Wiring Pi, or just start from scratch with good old C and gcc for the compiler. I could get the core functionality going and then port over parts of the code from the Arduino for ancillary functions, if it makes sense.  Certain things don’t make sense to port, like the CW memories code.  On the Pi you don’t have to deal with EEPROM like you do on the Arduino.  Anything that needs to be persistent across reboots can just be written to a good old file on the file system.  While certain things like persistent memory and sound support are easier on a Pi, deterministic and precise timing, which is needed for CW timing, is challenging on a multi-tasking environment like Linux.  This realtime kernel may be just the ticket.

Compared to the Arduino, there aren’t a whole lot of interfacing pins on the Pi.  To really get the power of this board you need to do I2C.  I’m thinking about what it would take to port my antenna tuner to the Pi.  That project uses I2C for controlling many relays, but there is also a need to monitor the voltages of the SWR bridge.  The Pi doesn’t have this capability natively, so an I2C device would be needed to supply this functionality.

All in all the Raspberry Pi is a versatile and powerful little board.  To get my feet wet I think I’m going to write a little bare bones C and see if I can get a basic keyer working and see where this takes me.  This is going to be fun.

 

Anthony, K3NG, is a regular contributor to AmateurRadio.com.

What do you do to complete these hamfest bargains? 3D printing for the win!

The best thing about it is that you can color-code the connectors, too! Finally, props to a CAD-ninja coworker for whipping up the beautiful SolidWorks model in a couple of minutes.

Ethan Miller, K8GU, is a regular contributor to AmateurRadio.com and writes from Maryland, USA. Contact him at [email protected].

Randy Hall, K7AGE, is a regular contributor to AmateurRadio.com , produces amateur radio videos, and writes from California, USA. Contact him at [email protected].

Using the strapped feeder to my Par 10/20/40m as my 472kHz antenna rather than my 2m/70cm feeder, the antenna current has nearly doubled with the antenna current meter now showing 30-33uA whereas it was 18uA before. This suggests ERP has increased by around 4-5dB (ERP proportional to I^^2), but we’ll see later. The Par antenna itself is lower than the 2m/70cm antenna and runs horizontally to a tree. Average height is around 3-4m AGL. The losses may be greater.

The picture shows the 472kHz coil used (a ferrite rod would be fine but since moving it is “lost”), the 472kHz homebrew transverter (left) and the 3C90 matching coil between transverter and antenna (towards centre, LHS of coil). The small meter measures antenna current and registered 18uA last night and 30-33uA now with the Par antenna with strapped feeders.

UPDATE 1420z: G8HUH (250km) is copying in daylight a full 8dB S/N better than last night. Encouraging.

UPDATE 1448z:  M0PPP (182km) seems to be coming in stronger than last night too and in broad daylight.

UPDATE 1700z:  M0PPP  is now spotting me at 1456z, 1538z and 1620z i.e. in daylight.   He was not copying me at all last night, so I think my signal IS stronger.

Roger Lapthorn, G3XBM, is a regular contributor to AmateurRadio.com and writes from Cambridge, England.

I was fortunate to attend the SOTA Rocky Mountain Rendezvous that occurred from July 31 - Aug. 3 in Buena Vista, CO. This year's Rendezvous was a no-host affair with informal gathering of SOTA Activators. Participants consisted of  locals, visitors in rented cabins, campers, etc.... It was a great time. The group that I was a part of rented a house about 12 miles outside of Buena Vista and little did we know there were two SOTA peaks within a 5 minute drive to the base of the mountains. Staying in the rented vacation home were Fred KT5X (aka WS0TA), Guy N7UN (ask NS0TA), John K1JD, Doc K7SO, Alan NM5S, Curtis KC5CW, my grandsons Reid KF5GYE and Boogie KF5GYD (both General Class), my XYL Cris KC5HZQ and myself.. Camping, about 5 minutes away at the base of Kaufman Ridge, was Steve, WG0AT along with Acorn and Barley.

We had a Dutch cookout on Friday night which attracted all the finest people including, Bryan N0BCB w/XYL and friends,Walt W0CP w/XYL,  Dave NN5K w/XYL. Seems like some others, but these are who I can remember. We had a great time grilling burgers, steaks, brats, etc... and swapping SOTA stories.

The RMR coincided with the 14er event put together by Bob K0NR, who stopped by the SOTA house on Saturday night along with his XYL Joyce, K0JJW. The event is an annual event (ham14er.org) which encourages hams to actuvate one of the 14,000 ft. summits in Colorado. As a SOTA chaser and activator, it is a cool event with lots of activity on both HF and VHF.

While in Colorado I was able to active 3 Summits, Kaufman Ridge (10,700 ft. ASL) W0C/SP-081, Horseshoe Mountain (13,900 ft. ASL) W0C/SR-064 and Mt. Sherman (14,034 ft. ASL) W0C/SR-061.

My grandsons and I were fortunate to be able to climb Kaufman Ridge with Steve, WG0AT and he two SOTA Goats, Barley and Acorn. We had a great hike and my grandsons loved interfacing with the goats. Steve did a video of our climb and it can be found at the link below.

https://www.youtube.com/watch?v=EcWGh7Wl3Gw


                                                               KF5GYE (Reid), Barley and Acorn on Kaufman Ridge



                                                          K1JD and AD5A on Mt.Sherman, 14,034 ft.


                                                             KF5GYD (Boogie) on Horseshoe Mt. (13,900 ft. ASL)


                                                      Panorama from Horseshoe Mt. (13,900)

It was a great trip and something all SOTA activators should consider doing.
Mike Crownover, AD5A, is a regular contributor to AmateurRadio.com and writes from Texas, USA. Contact him at [email protected].

For the first time ever I have been spotted on all the five bands that my Ultimate3 QRSS/WSPR kit (G0UPL design) is transmitting on. This is after 2-3 days of transmitting.

Right now I am using the beacon for discovering if the bands should open up on 24 and 28 MHz. The other three bands, and especially the 14 MHz band, serve as references to tell me that the transmitter is working. My antenna is not so optimal so I would be surprised if I am spotted far outside Europe. It is an end-fed 5 m long half wave vertical dipole which isn’t too bad for 28 and 25 MHz, and probably not very good at all on 21, 18, and 14 MHz.

Sverre Holm, LA3ZA, is a regular contributor to AmateurRadio.com and writes from Norway. Contact him at [email protected].