Tag Archives: Raspberry Pi

Why Ham Radio?

Fred's Truck Antenna
Fred’s Truck Antenna

Every so often, I drive Fred’s truck into work and people ask me what that big antenna on the back of the truck is for. I explain to them that it is for Ham Radio.  But the reply is usually, why ham radio – isn’t that outdated technology?  We have cell phones and IM, etc…what do we need Ham Radio for?  So I thought I would put down my thoughts as a relatively new Ham about why I enjoy spending so much of my time with Ham Radio.

Amateur Radio for Public Service

Public Service

The number one reason we still need Ham Radio along with all the other technology we now have is for public service.  When there is a disaster and cell phones, television, etc are all not working, Ham Radio operators provide the critical communication.

Ham Radio operators help locally to keep hospitals and first responders in contact with each other to help those affected by the disaster.

Hams also use our ability to communicate around the world on HF bands to help family members around the world to get in touch with loved ones affected by a disaster.

Ham Radio operators have been on the scene helping in every disaster from the earthquakes in Nepal to the recent flooding in California.

Amateur Radio Cube Satellites

Technology and the Maker Movement

I only became a Ham 5 years ago but many of my fellow Ham Radio operators got their license when they were in their early teens and used what they learned to launch their careers. Many have had very successful careers in STEM fields, all launched by their interest in Ham Radio at a young age.  As technology advances, so does the technology used in our hobby.   We even have a nobel laureate, Joe Taylor K1JT who is a ham. Joe has developed weak signal digital communication modes that let us communicate by bouncing signals off the moon!

As technology has advanced, so has the use of it in Ham Radio.   Most Ham Radio operators have one or more computers in their shack.  Many also have a software designed radio (SDR), where much of the radio functionality is implemented using Software, we use sound cards to run digital modes, which are a lot like texting over the radio, and we use the internet extensively as part of operating.  We can also make contacts through satellites orbiting the earth and even the International Space Station.

Most hams love do-it-yourself technical projects, including building a station, home brewing an antenna, building a radio or other station component.  In my day job, I am a program manager for software development projects, but its been a while since I have built anything. As a Ham I taught myself how to code in Python and about the Raspberry Pi and I built the DX Alarm Clock.

QSL Card from VK6LC in Western Australia

International Camaraderie

One of the coolest things about being an amateur radio operator is that you can communicate with other hams all over the world. Ham Radio is an international community where we all have something in common to talk about – our stations and why we enjoy ham radio.    The QSL card above is from a memorable QSO with Mal, VK6LC, from Western Australia, who was the last contact that I needed for a Worked All Zones award.  I must have talked to him for 1/2 hour about his town in Australia and his pet kangaroos!

Amateur Radio Map of the World

Geography Lesson

I have learned much about geography from being on the air and trying to contact as many countries as I can.  There are 339 DX Entities, which are countries or other geographical entities and I have learned where each one is in order to understand where propagation will allow me make a contact.  I have learned a great deal about world geography. Through exchanging QSL cards often get to see photos from so many areas of the world.

DXCC Challenge Award Plaque

Achievement – DXing and Contesting

DXing and Contesting provide a sense of achievement and exciting opportunity for competition. Many Hams work toward operating awards. You can get an operating award for contacting all 50 states, contacting 100 or more countries, contacting Islands, cities in Japan, countries in Asia, or anything else you can imagine.  Each of these operating awards provides a sense of accomplishment and helps to build skills.  Contesting builds skills through competition among Hams to see who can make the most contacts with the most places in 24 or 48 hours. Contesting also improves our operating skills and teaches us to copy callsigns and additional data accurately.

Teaching a License Class

Teaching Licensing Classes – Passing it On

Recently I have joined a team of club members who teach license classes to others who want to get licensed or upgrade their existing Amateur Radio licenses.  Teaching provides a way to improve my presentation skills and also helps me to really understand the material that we teach about Amateur Radio.  It is always a thrill at the end of the class to see so many people earn their licenses or upgrades.

There are so many interesting aspects of Ham Radio which is what makes is such a great hobby.  Getting your license can open up a world of possibilities.  Upgrading to a new license class provides more opportunities to communicate over longer distances.  Our club provides many resources to help you get your first license, upgrade to a new license class, and learn about the many aspects of our hobby.

3D Printing a Raspberry Pi Case

In a previous article, I wrote about jumping into 3D printing for fun and home-brewing.  I decided I wanted to try printing a custom case for my Raspberry Pi 2 Model B that I found on Thingiverse.  I chose one that had VESA mounting tabs with 75mm spacing in order to mount to the back of an older LCD monitor I had laying around.  I am doing this to create a dedicated mini-computer for running my M3D 3D printer.

RaspiCase
Custom Cases for Raspberry Pi found on Thingiverse.com

I’m printing the case you see above on the left.  There are other upper case options for mounting mini-fans should you need to provide extra cooling for your RasPi.  And if you are handy with one of the many 3D modeling software packages out there, you can mod this case (or any case) to fit your specific needs.

PRINTING THE CASE LOWER

I acquired a spool of black PLA filament (Hatchbox) from Amazon.

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While not specifically branded by M3D, I wanted to try other sources because the Hatchbox brand was less expensive on the order of 2.8:1 than the M3D branded filament.  I was taking a chance because I am learning that getting the temperature right for a brand not tested by the printer manufacturer  can be tricky.  I did have issues of the print starting to lift off the print bed (M3D is non heated).  But I recovered from that by tacking down the corner with a hot glue gun.  Maybe this would have printed better on a heated print bed or if I would have controlled the surrounding temperature better.

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Almost completed lower RasPi case
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Completed RasPi case lower

 

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Back of case showing “raft” before removal and cleanup

 

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Cleaned up lower ready for test fit

 

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Fits like a glove!

PRINTING THE CASE UPPER

Given the experience I had with printing with the Hatchbox filament, I wanted to see how printing the case upper would be using the M3D filament.   I just chose one of the other M3D filaments to contrast the black lower.  The printer’s program calculated this to be a 14 hr print.  But, the output is looking good for far–no lifting of corners or warping.

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About 12 hours later… DONE!

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Print completed for the RasPi case upper

 

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After removing the raft and cleaning up stray flashing (inside)

 

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After removing the raft and cleaning up stray flashing (outside)

 

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Fits great!  Just need to figure out the case screws.

As mentioned earlier, I wanted to print the case version with the VESA mounting tabs on the back of a monitor.  In this case, they needed to be 75mm spacing.  Aligned nicely!

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This was a fun project.  While not a perfect printing experience, it was good enough for a first major print project.  Lessons learned will be turned back into the printing experience and improved upon on subsequent projects.

After mounting this RasPi w/case to the back of the monitor, the next mini-project is to get the RasPi working with the 3D printer.  There appears to be groundwork already done in this area, and I will follow the path already paved.

-Wayne / AG1A

 

3D Printing for Fun and Homebrewing

I recently picked up a mini 3D printer made by M3D.com because I wanted to channel my inner-maker and see what it was like to dabble in 3D printing, but I didn’t want to spend the $1k-$2k or more for trying out something that I might not like.

This particular printer has a capability of printing objects up to 5.9″ x 5.9″ x 5.9″ in both PLA and ABS.  It is not the fastest printer out there, but with a little patience and sub $400 price, I was willing to give it a try.

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After unpacking the printer and settling on the white filament for my first dive into 3D printing, I looked for something that was simple, small, and easy to print.  I picked a flop-eared bunny for one of my daughters for Easter.  I pulled this 3D model from a well stocked source of 3D models called Thingiverse.

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It was easy get the print up-n-running.  Here is a sequence of photos during the 4 hour process with the final image being the bunny with all raft and supports removed.

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Now that I got thru my first successful 3D print.  I started thinking more of what can I print that might be practical and useful?  I know I have always wanted something to keep my charging cords from falling behind a desk or nightstand, so you can print these:

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And how about a nice custom case for that new Raspberry Pi you recently got?  Or custom printing some other little project box?

RaspiCase

There are many helpful projects you can print that already exist on the Internet and many colors to choose from.  Want to strike out on your own and brew your own custom widget?  Here is a chance to learn 3D modeling and there a quite a few freeware versions of software to choose from.   I recommend going to a site like 3D Printing for Beginners for starters.  There appears to be quite a bit of info on this site to keep you busy in learning about 3D printing.

-Wayne/AG1A