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Testing Dipole Antenna and Radio Mod

Not content with just modding my radio today to give it an external antenna socket, I had to go and build an antenna to try it out!

The washing line in the garden seemed like the most obvious place to put it as it’s quite high off the ground. This gave me about 13m to play with for a dipole, with an effective frequency of about 23MHz. Since my current radio doesn’t go as high as that, I instead used the antenna as a halfwave dipole, where it becomes useful at around 11.5MHz. This was quite a rough-and-ready experiment so I didn’t bother with matching or baluns or anything like that; I just plugged that bad boy in.

20140607_203904Immediately I was picking up loads of broadcasts, to the point where I guess my radio was pretty much overloaded with signals. That said, I was picking up many stations very clearly, and when my new radio arrives (Tecsun PL-600) I should have good selectivity to make better use of the antenna.

To make the antenna I split twin lead speaker wire to make two ~6.5m arms, but kept them joined together right at the feedpoint. At the feedpoint, I soldered on some 75 ohm coaxial cable. This section of the antenna is housed in a small piece of barrier pipe, into which I drilled some holes. I also made extra holes so I could fasten the coax with cable-ties and hang the feedpoint with another cable-tie. The arms of the dipole are clipped onto the washing line using clothes pegs, making it easily removable and portable.

The Issoudun transmitter site in central France is usually a good site for picking up stations from Ireland, but the dipole made the broadcasts much clearer. Here is a video of the modified radio and dipole in action, picking up Kurdish radio transmitted from Issoudun (apologies for video quality).

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