Antenna Bias Power; Radio Frequency (Rf) Filter - Sound Devices 688 User Manual

Better performance will usually be observed with a higher elevation of the re-
ceive antenna. This can provide a more direct line of sight to the transmitter
which improves signal strength. Shoulder mounted antennas are one example.
Care should be used with antenna selection in this scenario. Some antennas,
such as quarter wave (also known as quarter wave whip antennas), require a
ground plane (metallic refl ective surface usually perpendicular to the antenna).
Others, such as a half wave antenna and log periodic antenna (Also referred
to as paddle antenna), can be remotely mounted and do not require a ground
plane.
For best performance, Sound Devices recommends directional remote antennas.
Independent 12 volt antenna bias for powering active antennas is provided at
each SL-6 antenna BNC connector.
Many variables are involved with a successful RF link. As such, results for each
operation may vary.

Antenna Bias Power

If needed, 12V bias power may be provided to each antenna.
To supply bias power to an antenna:
1. Press the MENU button to access the Main menu.
2. Do one of the following:
Turn and press the Headphone encoder to select SL-6 > Antenna A
Power.
Turn and press the Headphone encoder to select SL-6 > Antenna B
Power.
3. Turn and press the Headphone encoder to turn bias power on or off.

Radio Frequency (RF) Filter

The SL-6 provides RF fi ltering which can allow operation in the presence of in-
terfering signals such as cell phones and TV stations. Selection is provided for
four different frequency ranges of operation.
To enable the RF fi lter:
1. Press the MENU button to access the Main menu.
2. Turn and press the Headphone encoder to select SL-6 > Antenna Filter.
3. Turn and press the Headphone encoder to select a fi lter range.
Options include: Wideband, 470-700 MHz, 470-590 MHz, and 580-700 MHz.
Wideband represents the guaranteed range of operation of an SL-6. Signals
above and below these frequencies may be usable. Filter selection depends
on the presence and magnitude of interfering signals. Generally, the nar-
rowest fi lter setting will give the best performance.
SL-6 POWERING AND WIRELESS SYSTEM
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