Category Archives: Building

Homebrew and kit-building.

OCX 3D Printed Case – by W4MHZ

After I built my 40m QCX transceiver, I needed a case.  I stumbled across a 3D printed case made by Mike Erskine (W4MHZ).  I wrote to Mike, asking him how to purchase one of his cases.  To my surprise, he sent me one for free, thanking me for my videos in the process!

Here’s a photo of my QCX in the W4MHZ case.  I used my sidecutters to make a couple of little nibbles in the plastic to make mine fit perfectly.

I’m very happy with it!

Mike is only charging $20 plus $5 shipping.  This is a good price.  If I had taken the time to design and 3D print my own case, I would have spent a lot of time and used up a lot of filament.  $25 is a bargain.

To get yours, contact Mike via email at:  3r5k1n3@gmail.com

Build a Computer to CW Interface

Using a  well-known circuit, I show you how to build a simple computer interface so  your logging software can send CW through your radio.

The logging software simulates someone using a straight key.  It changes the voltage on an RS-232 pin and the electronic circuit uses a transistor as a switch, grounding the lines as though someone grounded the contacts of a straight key.

This interface will let you work a contest or pile-up using your logging software – without having to use a key or paddle.

The circuit diagram: http://www.n3fjp.com/cwschematic.html

N3FJP website: http://www.n3fjp.com

Tripp-Lite USB to Serial Converter: See it on Amazon.com

Portable with the OHR 100A – 1st Contact

In this video, I show you one of my favorite places to work portable on Sunday mornings.  (It’s a business park a couple of miles from my house and nobody’s working there on Sunday mornings.)

I made a few contacts (one shown in the video) before I rode my bike home to watch football.

I finish the video by making an argument for the Elecraft KX1 vs. the OHR 100A. To me, an internal keyer is a necessity in a CW-only QRP radio.  That option pushes the OHR 100A up to $220.  For $80 more, the Elecraft KX1 is a more capable, modern radio with a digital display – and it has upgrade options that aren’t available for the OHR 100A… like two additional bands (4 bands, total) and an internal antenna tuner.

OHR 100A QRP Radio Build – Final Thoughts

I finished building the 40 meter version of the Oak Hills Research 100A QRP transceiver.  I also added the internal keyer.

In this video, I share my final thoughts about the build and the radio.

Summary:  It’s a great radio and I encourage you to build one.  The documentation could use some tweaking to make it easier to understand a few of the more confusing steps.  However, I built it without help and it worked right out of the gate.  If I can do it, you can do it!

OHR 100A QRP Radio Build- Part 2

I’ve got most of the (many!) capacitors installed, along with the crystals, etc. The kit is coming along nicely and I’m enjoying it.

My friend Doug Miller (W4DML) says. “Soldering is Therapy.”  I think there’s some truth to that.  When you’re soldering, you’re concentrating so much on what you’re doing that any other thoughts are pushed out of your head.  So, anything that’s bothering you goes away when building something.

Handling any object (like a soldering iron) that is 700 degrees Fahrenheit will cause one to concentrate – or suffer the consequences.

OHR100A_BuildPic2