Category Archives: Building

Homebrew and kit-building.

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

OHR 100A QRP Radio Build – Part 1

I bought the 40m version of the OHR 100A QRP radio last year and it’s been sitting in the box waiting for me to build it.  It’s time.

There’s something about the season changing to Fall that makes me want to build a kit.  I guess I think of Fall and Winter as being the time of year to do my hamming indoors.

I’ll build this slowly over the next week or so as time allows.  I’m not in a rush – but it’s good to have finally inventoried and sorted the parts. Now, if I can just keep the cats out of the room…

OHR 100A parts shown before the build begins.
OHR 100A parts shown before the build begins.