Wire-Lists #32: 4 Quick Tips for Antenna Performance

Social Media WireLists32 2 300pxWe've covered antennas for transmitters and receivers in a few of our previous Wire Lists. This week, we share 4 quick antenna tips that we might not have touched on prior:

The Straw Hack

Wireless signals are readily absorbed by anything containing water, which is why we advise not to let transmitter antennas touch the body or skin since this will reduce range due to the attenuated signal. What do you do in those situations where this is inevitable? Grab a straw! A regular drinking straw – opaque or clear both work - cut to the size of the antenna and slipped over it, will prevent skin contact and ensure that your signal remains strong. Another variant of this approach is to use aquarium air tubing.

Watch Where You Put It & Don't Bend It

Wireless systems depend on the full length of their antennas to deliver the strongest signal. When placing transmitters on talent, have them move to ensure that the antenna will not be bent or caught in, say, a belt or garments. Bending the antenna, even accidentally, cuts down on its efficiency.

But You Can Angle It

If you have two antennas that have to be close together, you can tilt them so that they are 90° angled to each other - one 45° to the left and one 45° to the right. Most Lectrosonics diversity receivers combine both antennas either in or out of phase with each other. By angling the antennas away from each other, a greater overall spacing is achieved between them and thus each antenna “sees” more of a different set of direct and reflected signals. In many cases, the performance difference of this arrangement may not be any different than having the antennas parallel. But in some situations, this will make a greater difference.

Give It Space

We have seen receivers, particularly when used in location mixer bags, perform poorly due to the close proximity of camera hop and IFB transmitters, also located in the bag. Frequency separation helps – the more spacing you can give your hop and IFB transmitters from your receiver frequencies, the better – but physical separation or remote antennas may be required for proper operation. One nice solution for bag systems is the coax dipole an item we sell for both BNC and SMA antenna connections, or you can make yourself.

And just a word about RF amplifiers and amplified antennas – the ideal amount of gain is “just enough to overcome the loss through coax cable” and generally, passive systems with correct gain structure will out-perform active systems, especially if too much gain is applied. Often, it is better to have a bit of attenuation through the antenna system – up to 6dB, in fact, rather than unity gain, especially in high RF noise environments.

Need additional pointers for your unique antenna situation? Post to our Facebook group. Our users often come up with hacks that we hadn't thought of but prove worthy in real life situations. Feel free to share yours if you have them!