FLEX-6000 Signature Series – FLEX-6000 Hardware Reference Manual
Page 42 of 48
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13 ANTENNA TUNER UNIT (ATU)
The FLEX-6000 automatic antenna tuner unit (ATU) is an antenna matching network designed
to present a 50 ohm, low SWR load to the power amplifier (PA) for efficient RF power transfer
on non-resonant antenna systems.
The FLEX-6700 and FLEX-6500 have an integrated ATU as a standard feature whereas the ATU
for the FLEX-6300 is a user installable option.
13.1 SPECIFICATIONS
Network Type: L Network
Antenna Connection: Unbalanced (coax)
Frequency Range: 1.8 to 54 MHz
VSWR Range: 8.3 - 300 Ohms (80m – 10m)
6.7 - 150 Ohms (160m and 6m)
Tune Power: 10W / 2W on 6m (automatically set by software)
Δ – It is not recommended to attempt repeated tuning of antennas with the ATU connected to
antenna systems that exceed the maximum VSWR on a frequency of interest. Some antenna
systems, such as physically short multiband antennas may exhibit a very narrow range of
resonance (a high Q antenna) in addition to being very reactive. The FLEX-6000 ATU is not
designed to tune these types of antenna systems. An external antenna tuner that is designed
to handle a wider VSWR range is recommended for these types of antennas.