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Testing a Channel for Outside Interference

Once a microphone and module have been successfully paired, turn the microphone OFF (leave the module ON). With the
microphone off, if the RF indicator still has bars showing, there exists interference. Note that RF interference can ebb and
ow. Sometimes it may appear as 4 steady bars on the RF indicator, other times, it may weakly occupy a single bar or two.
Generally, we recommend looking for another channel if ANY bars register.

Using Automatic Frequency Selection

In some areas the auto-scan feature may not select an interference-free channel. This is not because the system is
kind of environment, and do not want to use manual frequency selection, we recommend you do the following:
1. Start an auto-scan on the left module (1) using GR11. If there is no open channel in that group, repeat an auto-scan on
GR12. Continue this process until an open channel is selected. (see above for how to test a channel for interference)
2. Begin the auto-scan process on the 2nd module, but this time start with next available subgroup. For example, if on the
1st module you found an open channel on GR16, you would start scanning on GR17 on the 2nd module.
3. Repeat this process with the 3rd and 4th modules, starting with GR21.

Obtaining Local TV Tower Information

The most common source of RF interference to the UHF-5900 is TV broadcast towers. If you are experiencing dropouts,
static, or other annoying noises, and suspect RF interference, follow the instructions below to obtain information on your
proximity to broadcasting TV towers (United States).
1. Visit http://www.antennaweb.org (see note below)
2. Click ‘Choose an antenna’
3. Enter your zip code and hit ‘Submit’
4. On the next screen, hit the ‘Continue’ button at the bottom of the map screen
5. On the next screen, under the ‘RF Channel’ tab, take note of any channels between 38 – 51.
After obtaining a list of locally active broadcast channels, cross reference it with the TV channel frequency list (Page 20).
These frequency ranges are to be avoided as much as possible when selecting operating frequencies.
For example, let’s say you did a search in your area (this example shows zip code 05456) and received the following
information:
The only relevant channel is 43, therefore you would jot it down to cross-reference with TV frequency chart (page 20)
After cross-referencing, you fi nd that channel 43 uses the frequency range of 644 to 650 MHz. You would NOT choose a
frequency that falls in that range.
NOTE: antennaweb.org is a third party website and is not maintained by or affi liated with VocoPro.
Advanced Operation