Category Archives: Homebrewing

Articles and other information related to Homebrewing, station building, kit building, and other custom Ham Radio projects.

Our Latest “Tech Night” – A DSO138 Oscilloscope Kit Build

Our latest Tech Night became a Tech Day this past weekend. We got together on Saturday afternoon to build another kit – the DSO138 Oscilloscope. We had a great turnout with over 15 kit builders and helpers present.

Finished Oscilloscope Kit
Finished DSO138 Scope Kit in case

Brian, AB1ZO choose this really cool kit for us to build. Here are some specifications for the finished DSO138 Oscilloscope kit:

  • Analog bandwidth: 0 – 200KHz
  • Sampling rate: 1Msps max
  • Sensitivity: 10mV/Div – 5V/Div
  • Sensitivity error: < 5%
  • Vertical resolution: 12-bit
  • Timebase: 10us/Div – 50s/Div
  • Record length: 1024 points
  • Built-in 1KHz/3.3V test signal
  • Waveform frozen (HOLD) function available

The kit came with all Surface Mount parts pre-installed.

The kit included a very nice case to finish off the project. This was a pretty big project to complete in a single afternoon but quite a few of our builders completed their kits and got them working!

The gallery below contains more pictures from our kit build. Everyone was very focused on the building process as we all wanted to get our kits to work in the time we had together.

Some folks did not quite get their kits completed and are planning to finish them at home. The following are some links and videos to help.

Here are some videos which show the assembly of the kit and its enclosure and the operation of the completed scope. The first video shows the kit in operation.

 

 

 

 

I know that Brian is planning to do more kit builds throughout the year so be sure to keep an eye on our Tech Night page to see what is coming!

Fred, AB1OC

Why Ham Radio?

Why Ham Radio - Fred's Truck Antenna
Fred’s Truck Antenna

Sometimes 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  Isn’t that outdated technology?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?  Here are my thoughts as a relatively new Ham about why I enjoy spending much of my time with Ham Radio.

Why Ham Radio - Amateur Radio for Public Service
Amateur Radio for Public Service

Public Service

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

We also use our ability to communicate around the world to help family members 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.

Why Ham Radio - Amateur Radio Cube Satellites
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. Some have used what they learned to launch their careers. Many have had 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. Hams use sound cards to run digital modes, which are a lot like texting over the radio. 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.

Homebrewing

Most hams love do-it-yourself technical projects – 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.  It has been a while since I have built anything myself.  As a Ham, I taught myself how to code in Python and about the Raspberry Pi and I built the DX Alarm Clock.

Why Ham Radio - QSL Card from VK6LC in Western Australia
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.  That is 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!

Why Ham Radio - Amateur Radio Map of the World
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.  I have learned where each one is in order to understand where propagation will allow me to 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.

Why Ham Radio - DXCC Challenge Award Plaque
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 or contacting 100 or more countries.  There are also awards for 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.

Why Ham Radio - Teaching a License Class
Teaching a License Class

Teaching Licensing Classes – Passing it On

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

There are so many interesting aspects of Ham Radio which are what makes it 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.

Anita, AB1QB

Feb 18 DSO138 Kit Building Tips

Hi DSO138 kit builders,

I wanted to share some tips to follow for our 18 Feb Kit Build from 1-4pm. As I already built my own kit, I wanted to share some advice.
I know not all of you can attend, but for those of you who can, please read below. I’ll also post on the website along with some pics.
  1. Make sure you bring a magnifying glass AND a multimeter. Also, might help to bring an LC meter too (though I didn’t have one at the time) The color bands on the resistors are particularly impossible to see, so I had to measure the resistance of every one. I even did it 2-3 times to make sure I was right.
  2. To test your kit at the end of the night, you need to supply it with power. You can do this 2 different ways. The first is bringing a 9V battery along with 9V battery leads terminating at the end of a female port as shown below. The second is grabbing a power adapter rated for no higher than 12 V again terminating on a female port with pic shown below.
  3. You might want to bring a small Phillips head screwdriver (for eye glasses) in order to perform probe calibration.
  4. If you want, bring your laptop so you can download some signal generators (using your sound card) in order to play with the oscilloscope. In order to do this, I ended up using a BNC to an audio adapter which I purchased off of Amazon Prime. I’ll bring mine in case you don’t have one
  5. If you have a standalone signal generator, please bring it, along with BNC wire connections for the o-scope.
DSO138 kit power supply port
DSO138 power supply port
9V battery adapter
9V battery adapter
12V power supply (stolen from a Linksys router) with port (top-middle)
12V power supply (stolen from a Linksys router) with port (top-middle)

In order to do some testing, we are going to want to use either signal generators that club members graciously bring in, or you can use your laptop’s sound card. To that end, Mike (K1WVO) suggested a really nice link to do this.

I’ve tested most of these and they work fine on my scope.

If I have any other thoughts, I will update this post.

Thanks and 73,

Brian, AB1ZO

Radio Amateurs Developing Skills Worldwide