Helical Antenna Alert
Posted on April 20, 2011
Yes, there’s a really strong string about helical antennas somewhere, but I can’t find it. So here’s what I am excited about adding.
Yes, there’s a really strong string about helical antennas somewhere, but I can’t find it. So here’s what I am excited about adding.
In TV Technology (tvtechnology.com), Apr. 11 edition, Page 12, there’s a very informative article by Steve Harvey titled WIRELESS MICS ADJUST TO THE NEW RF ENVIRONMENT. The wireless mic aspect is, of course, interesting as a Part 15 subject, but right now I am talking about a photograph showing double-length helical antennas inside transparent tubes with the open end of the tubes pointed toward the wireless receivers, and the back end attached to mic-stands.
THE SIGNAL IS SHOOTING OUT OF THE END OF THE TUBE.
These antennas are described as highly directional helical antennas, which offer the most forward gain and the tightest polar pattern.
In discussions of helical antennae for Part 15, it has been assumed that radiation will be toward the horizon from all sides of a vertical spiral, but now I’m not so sure. If the example in the article is a firm indication, the signal shoots out the top or “far end” of the helix.
It doesn’t matter that we’re using lower frequencies because the antenna sizes we are forced to use are more suited for HF.
I wanted to link the photo, but on the tv tech website the electronic edition only allows up to page 10 and then requires subscription. As a veteran tv producer I have a complementary subscription, and so could you, by filling out their form. Just say “presto” and start a video division for your station.
My scanner is not up right now, so, no picture.