Tag Archives: Arduino-Raspberry Pi

A Good ‘Day’ To Be A Ham? by Paul Mills, AC0HY

We have such a wonderful hobby with its myriad, almost limitless facets. No room for boredom here! Paul Mills, AC0HY, President of The Kaw Valley Amateur Radio Club [Kansas], wrote a very interesting article in their Newsletter, THE TRANSCEIVER September 2017. It’s republished here with his permission.Club Web Page: www.KVARC.org     Layne AE1N

A Good ‘Day’ To Be A Ham? by Paul Mills, AC0HY

I was thumbing through some magazines for inspiration, as I often do. Magazines for me are seldom read but frequently browsed. In some, I observe the advertisements more than I do the articles. I do read a few articles from beginning to end. But to a large extent, I look at titles, pictures, schematics, and captions. And frequently I scan the article for areas of interest. Today this caused me to think about how things have changed in my lifetime.

My earliest days in radio, tubes were still the norm. Transistors were out there, but the quality was not great, and most were used in portable or mobile electronics. Equipment was large and heavy. Transmitters and receivers were frequently separate. Power amplifiers were very large, and often two pieces – the amplifier, and the power supply.

Over the years, transistors changed, the move from germanium to silicone greatly improved reliability, though there still remains a place for a few germanium devices. And while early transistors were bipolar devices, there came to be many FET’s and a number of new materials and techniques used in their construction.

In many ways, this was a great time. It was easy to roll up your sleeves, and put together circuits, and observe how they worked. During these days, many parts houses sold electronics components. At one time, Topeka had 5 or 6 wholesale parts houses. Radio and television repair was a common business.   But even before this era was over, Integrated Circuits, and Large Scale Integration was upon us.

In many ways, this was a great time for the radio enthusiast. Parts were widely available, and building from scratch was therefore fairly easy. Likewise, repair was possible due to the wide availability of parts. Now Very Large Scale Integration and surface mount technology has totally changed electronics, and thus radio. This has done a lot of positive things for us.

Consider that your Smartphone is tiny compared to the radio-telephone of the 1970’s. And in addition, the Smartphone contains a room full of similar era computing power. On the down side of all of this, parts are harder to come by. If you need parts, you will probably have to order them, and wait. And in many cases, it is cheaper to replace a product than it is to repair.

What does this mean to us as ham radio operators? It means that to a degree, all of us have become appliance operators. Does that mean that we are doomed to a dumbed down hobby? NO! There are plenty of things we can do if we so desire.

Most obvious of these things we can still do is to build our own antennas. There are lots of antenna designs that we can experiment with. Many antenna projects can be done with a spool of #12 wire, and some homemade insulators. Let your imagination run wild.

Those who would like to play with electronics may find some satisfaction with parts houses such as Mouser, DigiKey, Newark, Arrow, MCM, Jameco.

Additionally, eBay can be a wonderful source for things to experiment with. And, if there is something you forgot, don’t forget the Radio Shack replacement –Amazon. You will be surprised at what you can find on Amazon – and if you have Amazon Prime, frequently have in 2 days with free shipping.

In many cases, instead of building from scratch, you will buy things like RaspberryPi, Arduino, or other small single board computers. These can be used to automate various tasks in the Shack. On eBay, there is a wealth of boards that can be found to do just about anything you want. Your imagination is the limit to what you can do here. There are SDR radio kits, various parts and pieces that can be cobbled together to create your own receiver, transmitter, transceiver, etc.

If this seems hard to believe, start searching the internet, you will find that there are lots of people already doing these things.I know these are not for everyone, but hopefully it will cause some of you to broaden your horizons. Even if you do not choose to do any of them, it can be interesting to find a read about what others are doing.

Until next time…73 de AC0HY

Ham Radio Hobby

Add CTCSS PL Tones to Your Old VHF Rig

Last week I gladly accepted a free Azden 2m FM transceiver model number PCS-4000 that was offered to me.  You have to love the old free stuff!  The only capability this 25W rig was missing is the ability to transmit CTCSS PL tones or sub audible tones to activate a repeater.

I found the manual and schematics online and found that this rig was built to accept a tone generator as an add-on. See below.

PL Tone Mod Circuit

Below is a photo showing the jumper locations for the tone input.  I soldered some leads with a home brew disconnect to easily remove the cover in the future.PL Tone Mods

Below is a photo showing an added 1/8″ mono jack for the input tone.

PL Tone Mods

For an input tone, I used an Android cell phone with a frequency generator App to generate the PL tone.

PL Tone Generator

I can experiment with other ways to generate the tone such as an Arduino with RC filters etc.  I can also try to insert a 700 Hz tone with my Arduino keyer for MCW.

Below is a photo of the rig set up for a local repeater.

Completed Mod to add PL Tones

So now to quote Pete Juliano “Bob’s your uncle”!!!

73,

Mike, AB1YK

My SSB BitX-40 build from VU2ESE

Below is a photo of my BitX-40 kit from Ashhar Farhan VU2ESE in India with my very own custom designed case.  The kits are available from http://www.hfsigs.com/

The top cover shown is powder coated steel mesh.

BitX-40 Enclosure

The sheet metal housing was designed in a solid modeling software package called Onshape. This web based software is free to use if your designs are to be available to anyone who signs into an account.  This design is “in the cloud” and considered “open hardware”, available to anyone who would like to use it.  Below is a screen capture of my Linux desktop running Onshape within a web browser.

BitX-40 Enclosure CAD Design

With access to a CNC punch press and a 90-ton brake press, a coworker of mine helped out with a bit of “government work”!

I left out some of the detail in the housing to let others enjoy the use of a drill and allow for some creativity with a customized placement of components.

BitX-40 Enclosure with Board

Some of the wires are not needed but may be useful in future “hacks”. The image below shows some of the wires removed from the “Molex” connector.  A small sharp object can be used to push in on the barb to remove the contact for a future project.

BitX-40 Cables and Connectors

See http://bitxhacks.blogspot.com/

I used my sketch to drive the LCD screen and the SI5351 chip using the Adafruit library.  The checkered block moves left and right between the arrows to indicate when I am at or near the end of travel with the tuning potentiometer.

BitX-40 Frequency Stationary
Stationary

When I move the block all the way to the right with the potentiometer it turns into an arrow and automatically increases the frequency. To make it stop just turn the potentiometer to the left.

BitX-40 Frequency rising
Frequency rising

I like the ability to scan the band without having to turn a knob!

Below is an image showing 12v and 24v voltage regulators and electrical tape on the housing tabs.  12v is for the majority of the wiring and I used 24v for the IRF510 PA.  The black tape looks nice behind the black mesh cover.  while testing I measured about 4W RF output with 12v feeding the PA and 16W RF at 24v.

BitX-40 Enclosure

The bottom has extruded “feet” along with stick on feet to keep the rig from sliding.

BitX-40 Enclosure

I used an SO-239 connector for the antenna.  I saved the BNC connector from the kit for test gear.  The red terminal post is connected to 32v from a repurposed HP printer power supply.  The barrel jack is connected to 16v from the same supply.

For more information on the case, you may contact me through my QRZ page.

73,

Mike (AB1YK)

Home Brew Your Own Arduino UNO

The first question you may ask is, Why would I want to build my own Arduino UNO?  Economically speaking it does not add up in your favor after you acquire the parts and consider the time it takes to put it all together.  This is especially true when you consider that a Nano “clone” could be purchased for around $3!  You might have a permanent use application that makes building one your best option?  Maybe you just like to learn and do stuff just because you can!

The unit below is built on a prototype shield that has become the main board.  For my keyer application, I have no need of USB communications and I can keep the wiring down to only what is needed.  The 5v regulator will soon have a small heatsink as it gets warmer than I would like.

Homebrew Arduino UNO

Below is the other side of this board.  I used #4-40 screws as “legs”.

Homebrew Arduino UNO

Instructions for building one yourself on a solderless breadboard can be found at https://www.arduino.cc/en/Main/Standalone

Instructions on burning the bootloader with another Arduino can be found at

https://www.arduino.cc/en/Tutorial/ArduinoToBreadboard

and

https://www.arduino.cc/en/Tutorial/ArduinoISP

If you run into trouble like I did by getting the “wrong” ATmega328 micro controller you can get work around instructions at http://www.crash-bang.com/resource/bootload-atmega328/

73,

Mike AB1YK