Monday, December 30, 2013

Homebrew CW Paddle: Cost $0

So browsing around various email reflectors and online communities I keep hearing about how expensive ham radio gear is.  People keep saying that it costs too much to get into HF.  I wanted to debunk that a little.

I have already built a SWL RockMite-40 kit, but I didn't have a paddle to go with it.  So I wanted to build one, and at the same time show what could be done on the cheap.  The paddle that I came up with isn't overly elegant, other than in its simplicity.  My craftsman ship isn't compliment worthy, other than to say that it works.

The parts list is simple.

  • Base moulding corner block laying around, but any scrap piece of 1x4 would work.  
  • Three inches of scrap of 1x2 white pine left over from a different project.
  • One cheapy kitchen butter knife that I found in a scrap bucket
  • Stereo cable from an old set of headphones
  • Some screws from the "misc fastener" bucket

And that is it.  I used basic tools (as you'll see from the pictures, things like a drill press would have made for a cleaner job), nothing special was required.

My tool list was pretty basic also:

  • Power drill
  • Drill bits
  • Hacksaw
  • Screwdriver
  • Pliers
You don't get much simpler than that.  Now then, on to some pics:

Heck, I even took a short video!  This is me keying CQ into a dummy load.  Imagine that, a dummy on both ends of the radio!  ;-)

And, for the nay sayers, here is a pic of a fully functional HF station, ready to rock on 40m.  Total cost:  ~$50

What's that?  You need a tuner?  Well, at 250mW-500mW, I would recommend a resonant antenna instead of a tuner.  But if you must have one, add in the $65 Emtech ZM-2 tuner (which would happily tune a clothes hanger) and you're ready to go.  Total cost for a flexible HF station: $115

Well shoot, you also don't have an antenna either?  Not a problem, we can cover that too.  A 100ft roll of RatShack speaker wire is $14.  Measure out ~31', split it (use a zip tie to keep it from splitting further) and use the rest as the feedline to your tuner (or just cut it at that length and solder it to some 50ohm coax and go straight to the radio). You can find it elsewhere much cheaper, you just have to look around.  You could probably score some wire for free by doing a bit of dumpster diving or asking a local construction company nicely.

Here is a completely portable ready to go HF station, with tuner and antenna, for a total cost of ~$130.

Now, admittedly, it takes some time to put the kits together, and you need some tools to do so, which also cost money.  But most of the tools needed are already laying around the house with the possible exception of a soldering iron, but those can be had cheap, just look around.  If all else fails, a RatShack soldering iron will get the job done for $10 and it even comes with some solder!

After the tools, it takes the knowledge.  Which is the essence of ham radio.  You don't need a lot of knowledge about electronics to assemble the kits, just follow the directions and you'll be done in no time.  But use it as an opportunity to learn about how the radio works!  Then you'll have the knowledge for next time, and you get tackle a bigger project.  Maybe a BitX or something like that!

Which brings us to the crux of it.  After the tools and the knowledge comes the drive.  The desire to make it happen.  The willingness to put effort into something.  If the desire and drive are there, all the rest will fall into place.  And if it doesn't, call me and maybe I can help!

73 and Happy New Year!

Richard, KK4JDO

Friday, December 27, 2013

Enclosure for KF5INZ "Easy Digi" Sound card interface

To follow up on the last KF5INZ "Easy Digi" post, I wanted to show you the enclosure that I made for it.  This post will be more pictures than typing, because it is easier to show than to type.  Plus I'm feeling kinda muddled this evening and am having trouble typing.  Blood sugar must be messed up again...

I decided to use the venerable Altoids tin for this project.  They work great for this sort of thing.  Plus the mints are delicious!

I decided to use 1/8" Stereo jacks for all I/O ports.  I've done this before on a past project and it works well.

I marked the locations for the audio jacks by putting them in the bottom of the tin and marking the location with a Sharpie.

If you look close, you'll notice that the line is a bit higher than the jack, this is due to the pens thickness and ends up giving a perfect location for the jack with enough room to close the lid.  I discovered this method after messing up and putting one just a bit too high.

I found the perfect method (courtesy of Don, K3RLL) for making holes in Altoids tins.  A simple, basic, paper hole punch makes just the right sized hole and leaves a nice clean edge.

You can see where I have tried using a step drill.  Not nearly as clean.  All jagged and full of burs.

Test fitting the jacks in place to verify that the lid would close with the slip ring in place.

 Now to connect the PCB to the jacks.  I started by soldering the wires to the board with plenty of excess wire to reach the connectors.  I then did a test fit to get the proper wire lengths and attached the jacks with the whole mess outside of the tin.  I used heatshrink tube to clean up the clutter.

I used two layers of double-sided tape to hold the board into the tin to avoid any short circuits.  I cleaned the inside of the tin with alcohol before sticking it down.

And the finished product!  The flash made pictures difficult due to the shiny tin, but you can see the cable routing.  This was a quick and easy project from getting to kit to having a completed and usable sound card interface!

Here are the details on the cabling.  The jacks on the left go to the rig, and the jacks on the right go to the PC.  Something like this:

Rig Left (To Rig) Right (To PC) PC
Spkr RX Audio RX Audio Mic
Mic TX Audio TX Audio Spkr
Mic PTT PTT Serial

The columns labeled rig and PC denote what ports the jacks on the interface connect to.

I hope that you enjoyed the little picture show!  Best of luck with your project.  If anyone is interested I will post about how I built the cables.


Richard, KK4JDO

Wednesday, December 25, 2013

Christmas Ham

My wife did the best that she could as far as getting a present for a ham radio operator goes.

A speaker mic for my iPhone!  Who knew that these even existed?  ;-)  What a better way to show off how HamSexy I am than using a speaker mic when talking on the phone!  Of course, now I'll probably ID when on the phone out of sheer habit.  I can see it now:


Mom:  "Hello?"

Me:  "Hi Mom, how are you today?  From KK4JDO"

Mom:  "Ummm, hi, I'm fine?  What were those letters and numbers?"

Me:  "Oh, that was just my call, don't sweat it.  Gotta go!  Love you"

Mom:  "Ummm, love you too dear"

Me:  "Talk to you later, 73, KK4JDO clear"

Mom:  "Uhhhh, bye!"

How absolutely awesome will that be?  I guess it would be less awkward with family than it would be with the doctor or a work call.  Although telemarketers could be fun.  I could give them reception reports and be sure to throw in a lot of hammy slang and abbreviations.  ;-)

Anyhow, what a great present!  I hope that you all had a wonderful Christmas replete with family, friends, and food.  Merry Christmas and Happy New Year to each and every one of you!


Richard, KK4JDO

Wednesday, December 4, 2013

KF5INZ "Easy Digi" Build

Today's post is to cover the quick build of the KF5INZ "Easy Digi" Sound Card Interface.  This was a great little kit.  I can't find the parts separately for what this kit costs.  I can't stress enough what a great value it is at $11 shipped.  The pcb is good quality and the instructions are almost unnecessary it is so easy to assemble.  I think that it took me a total of 15 minutes from opening the package to having a completed board.  I still need to build a box for it, but the board itself was done in just a really short amount of time.

On to the pictures...

The kit came in a typical little yellow envelope, with the parts and pcb in a little zip-lock bag.

The parts are all easy to identify and can be sorted in seconds.

Here is the optoisolator IC and diodes installed .  The polarity of the diode is silk-screened on the board.

Then the resistors.

Then onto the capacitors, all two of them...

And finally the audio transformers.  Quick and easy!

That has it all completed and ready to go, now I just need to build a box for it and build some cables to connect it.  The intent of this board is to connect my 2m rig to my Raspberry-Pi using a USB soundcard to build up an APRS Igate using Xastir and one of the soundcard modems.

I'll do another post once I have it completed.

Thanks and 73,

Richard, KK4JDO