Yaesu FT-8900R Operating Manual page 31

Typical situations that might cause inversion to occur are:
Connection of an external receiver preamplifier
Operating through a repeater
Connection of an external linear amplifier
Note that code inversion does not mean that any of the above listed equipment is defective.
In certain amplifier configurations, the output signal (phase) is inverted from the input. Small
signal or power amplifiers having an odd number (1, 3, 5, etc.) of amplification stages may
result in inversion of a transmitted or received
While under most circumstances this should not occur (amplifier designs and industry
standards take this into account), if you find that your receiver squelch does not open when
both you and the other station are using a common
both) can try the following:
1. Press the
2. Rotate the
3. Press the
mode:
TRX N
RX R
TX R
TRX R
4. Press and hold in the
normal operation.0.

Remember to restore the default setting to TRX N (Encoder; Normal,
Decoder; Normal) when done.
Yaesu FT-8900R Operating Manual Expanded Edition (courtesy of W5JCK)
momentarily to enter the
SET key
knob to select
DIAL
knob momentarily, then rotate the
DIAL
: Encoder; Normal, Decoder; Normal
: Encoder; Normal, Decoder; Reverse (Inverted)
: Encoder; Reverse (Inverted), Decoder; Normal
: Encoder; Reverse (Inverted), Decoder; Reverse (Inverted)
knob for ½ second to save the new setting and exit to
DIAL
code.
DCS
code, you or the other station (but not
DCS
mode.
Set
Menu #11 DCS.N/R .
TONE CODED SQUELCH
knob to select the
DIAL
Page 31 of 77