| | TECHNOLOGIES
FOR WORSHIP MAGAZINE ONLINE January 2002 Wireless
Help File by Kevin Sanford While wireless technology
continues to offer more user-friendly products, setting up and installing a wireless
system can be both challenging and problematic. It is not an exact science. Even
the most experienced technician will run into frequency interference and unexplained
static. Kevin Sanford has been a wireless specialist for the past 10 years. He
has worked in all wireless applications; providing sound equipment for churches,
corporate events, theatrical productions, as well as every major television network
and production company nationwide. Through this column, Kevin hopes to pass on
some useful bits of information to help you make more informed choices when buying,
installing and running your wireless systems. He will reveal the secrets to frequency
coordination, proper placement and troubleshooting. This is a regular column,
so feel free to write in with your questions or wireless related issues. Q.
We often hear static when we turn our mic on. In fact, we've recently noticed
that the pastor can only get 10 feet away from the wireless receiver before he
cuts out. Any ideas why this is happening? — Bellville, TX A. This
could be one of two problems. First, make sure that your antenna isn't broken
in any way. Without a working antenna the microphone cannot properly transmit
to your receiver. This will cause static interference or dropouts. If you have
a lavalier, pull on the antenna gently to check it. It should not give. If you
feel it stretch then it is broken and needs to be replaced. Any wireless lavalier
antenna needs to be replaced once a year. As the current passes through, the antenna
weakens and will inevitably break down over time. Secondly, you could be experiencing
interference from a local TV, radio or data channel. All wireless technology,
including wireless mics, in-ear monitors, walkie-talkies, wireless communication
devices, digital lighting, etc, must be carefully coordinated so that the frequencies
won't interfere with each other or other local RF sources. If you think this may
be your problem, call your wireless vendor or go to the FCC's frequency site on
the web, www.fcc.gov to guarantee that local stations aren't interfering with
your wireless channels. Q. I would like to buy a new wireless mic for
our solo singer in the gospel choir. While looking online, I noticed that some
units are listed as "frequency agile"? What does frequency-agile mean? —
Gainsville, FL A. Frequency agile means that there are options of multiple
channels within a single unit. This technology has come out in the last few years
and has made it much easier for almost anyone to operate a wireless microphone.
If you purchase a unit and experience interference from a local RF source, you
can just change the channel to another frequency within the allotted bank. Almost
all the manufacturers on the market offer frequency-agile systems don't settle
for anything less. There's nothing worse than spending a lot of money on a unit,
being excited to try it out on your first sermon, and hearing nothing but the
morning news from your local TV station. Q. Within the past 3 years,
my church has purchased several wireless units. Last month we bought two more
mics and are now experiencing interference within the entire system. I have a
feeling the problem is frequency related. How do we know when the mics are too
close in frequency? — Pittsburgh, PA A. There is a basic formula
you can use when putting two or more wireless mics together in the same location.
The frequencies should not be less than .250 MHz apart from each other. If you
have a microphone in the UHF band with a frequency of 625.000 for instance, your
next mic should be at 625.250 to avoid intermod interference between the two.
When adding more mics, just continue the math. This can be used up to 8 units.
After 8 units, my advice is to go with another frequency set. Also, always remember
to consider other RF sources in your area. Even though your mic frequencies may
be compatible, you could be interfering with other frequencies in your neighborhood.
Coordination and education is key. Wireless problems? Write to Kevin.
For a published reply, send your questions to Technologies for Worship Magazine,
c/o Wireless Help File; PO Box 140, Queensville ON Canada, L0G 1R0.
Educational Gateway Kevin Sanford has been a wireless specialist for the
past 10 years. He has worked in all wireless applications; providing sound equipment
for churches, corporate events, theatrical productions, as well as every major
television network and production company nationwide. Through this column, Kevin
hopes to pass on some useful bits of information to help you make more informed
choices when buying, installing and running your wireless systems. Kevin is also
the owner and founder of Wireless First, located in New York and Boston. Wireless
First specializes in renting and selling wireless equipment nationwide. | | |