The HamRadio “Maker” Challenge

A few Weeks ago i had the idea of making a Challenge for HamRadio operators. Not a Challenge like eating a spoon full of Cinnamon or post a picture from a pen that will stay under your boobs (really?!)

No. I thought of something like:

Scenario: X-Event occured today. There is Y-Problem.
Goal: You will have to find a way to build/make/hack Z
Rules: Because of the X-Event you only have Q-Parts to reach your goal.
Rewards: Recieve something (like a Diploma) for the 3 People with the most points.
Points are given by different factors like speed, creativity, “1337-value”, …

I am not sure if you understand what i mean so let me make a easy example:

Scenario: You made it. You are the only CW guy that will take part to the DX-Pedigion to P5! While taking a Nap on the Airplane you suddenly awake and it comes to your mind that you have forgotten your Morse-key at home. You remember that you put a big piece of Paper over it with the Inscription: “DO NOT FORGET!!”. You grab the Telephone on the seat in front of you, swipe your Creditcard and call all Hamradio shops in P5 but noone has a Morsekey for sale. You realize that you have a big problem and that you have to come up with a solution quick because kenny (the main organizer) is getting suspicious.
Goal: Build a Morsekey with the things you find in your Hotelroom. Special points will be given if you can build the Morsekey with parts from Insode the Airplane (parts you have access as a passanger! Dont rip the plane apart).
Rules: Use whatever parts are in a “normal” hotel/airplane. A normal guest/passanger must have access to these parts. No vandalism! You may also use parts that a “normal” person has in its hand luggage. You can also modify things. The Morsekey has to work with a normal HF Radio/Your Radio.
Prove: Make Pictures/Videos, write a small text what you used and why. Make a Call/QSO. Confirm that QSO with a Video. If you havent learned CW yet Send a Call: “YourCall HAM Challange” and get a video from a receiving station.
Points: Points will be given for speed (time from anouncement to QSO/Call), creativity, “HackValue” by a Jury containing: Me
Rewards: The winner of every Category will get a Printed Diploma and the official Title:”Problemsolver” (issued by:Me)

That is just a small and easy Challange that came in my mind right now but i have a few ideas for interesting and funny Challanges.

So Why should we do that? Why wasting time instead of logging some DX stations instead?: Well i dont know you but i personally think that the HAM Radio Hobby is really special in what it is and what you can do. And it went from “i made all of my own stuff with nothing like a bunch of old stuff” a little bit to “i shopped that VooDoo endfed long wireantenna that can do all bands with just 6.4m lengh”. I dont judge anybody. I fully understand that some people like to build and some people like to use. I am ok with that and i am also one of the electronics consumer and not that big of a electronics builder.

I think the Spirit of HAM Radio is to make and test stuff and its always fun when you have a Problem and solve it. You can solve it quick and dirty. You can hack that thing laying in the corner to something usefull. And you can build something beautifull and good that everyone admires you. It is up to you to choose your path.

The other thing is: (and i really dont want to hop on that survival/emergency train!) What if you have to make something with really a habd full of parts. Very much can be done with very little parts. Believe me.

I would like to publish your ideas to inspire other people. To help them learn and understand the principles of physics and how things work.
Please write me a email or contact me on twitter and tell me your opinion on my idea. I would really like to try this and see if its the fun that i think it is.

Best wishes

Email: oe8hsr [at]

Twitter: @MeltdownCore

Linked Dipole Calculating the Wire Lengh

This is the first time that i Calculate an Antenna so i have looked the formula up in an Antennabook that i have.

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I have put some extra Lengh on the different wires so we can trim them later when we measure the SWR of the Antenna.

The Lenghs from the different Bands are:

L80m: 9.85m

L40m: 3.30m

L30m: 2.25m

L20m: 2.85m

L10m: 2.75m

Please note that the Lenghs are per side so we need 2 of all Lenghs.


Best Wishes


Linked Dipole Balun Mounting

So the Balun is on the Centerpiece, Now we want to connect the Balun to the Dipole Side.

Cut the outerside of the Coax Cable from the Cable like shown on the Picture. Note that you should not cut too wide in the Wire.

When you are finished it should look like on the picture.

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Now use a needle or a small screwdriver to open the outer Conductur of the Coax wire. You do want to take your time on this step. Be carefull so you dont break the outer conductor.

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When you are finished wind the outer conductor around and make it nice ant tight.

Cut it about the same lengh as the inner conductor.

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Put some heatshrink on the outer Conductor and on the point where the 2 Conductors meet on the Coax cable.

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Get yourself 2 6mm Cable connectors and solder them on the ends of the 2 Wires.

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When you have finished soldering, take 2 x 6mm Screws with a lengh of about 15-20mm, 4 washers and 2 nuts.

Just put them on the Centerpiece as shown, We need to put the Dipole wires later on the Centerpiece.

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Best wishes


Linked Dipole The Balun

Our Linked Dipole will have a 1:1 Balun.

I have bought the Toroid and the 13m Coax cable with the attatched connector from SOTABEAMS.

I have used the following Parts:

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On the SOTABEAMS site where you can buy the Toroid there is a really nice “Manual” where it shows how to wind the 1:1 Balun.

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In our case when we will make a Balun for HF we have to make 7 turns on one Site and then 6 turns on the oposite side as shown on the Picture.

Always remember when you wind a Balun or a Transformer a “Turn” is then the cable goes throu the Toroid.


I measured about 50cm from the Coax cable and put it throu the toroid. I fixed the first turn with a small ziptie.

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Then you can wind the Balun as shown on the Picture from SOTABEAMS but with the 7 + 6 Turns.

When you are finished winding the coax you can put the a second ziptie on the outcoming Coax Cable.

Now mount the Balun on the 3D-Printed Centerpiece with 2 Zipties and use another 3 Zipties as a strainrelief for the remaining Coaxcable that goes to the Radio.

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That is the first Part on our way to the Linked Dipole.


Best Wishes


Linked Dipole 3D-Printed Parts

I designed the 3D printed parts in a way so that you can wind the dipole Wires and the Coax Wire on the middle Piece.

You also will need 8 Isolators.


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The Settings of the 3D Prints are not that important.

I have printed my Parts with 20% Infill and it worked fine.


Best Wishes


Homebuild Linked Dipole

I am planning to build a Linked Dipole for Portable use.

I want to build it for the 20m, 30m, 40m, and 80m Band.

The Centerpiece and the isolators will be 3D Printed and the Centerpiece is constructed so you can wind the wires and coax cable directly on the centerpiece.

I will make several Blog Entries for the different steps of the build.

Best Wishes