microHAM MK2R Manual page 49

PTT OUTPUTS
MK2R has four (4) PTT outputs for each radio: PTT1, PTT2,
PAPTT and LNA PTT. PTT1 and PTT2 are brought out to the
DB37 Radio connector. PAPTT and LNA PTT are RCA jacks for
connecting to external devices.
PTT1 is wired to the radio microphone jack and is normally used
to switch the radio into transmit in VOICE and CW mode.
PTT2 is wired to the radio Accessory jack and is used to switch
the radio into transmit in DIGITAL and FSK modes.
NOTE: PTT2 (rear panel" PTT) is used by some radios
to mute the microphone and disable microphone
processing circuits (audio equalizers, compression,
clipping, etc.) that can distort digital modulation.
PA PTT1 & PA PTT2 are available on the rear panel RCA jacks. They are designed for switching amplifiers for
each radio. Each PA PTT is enabled by checking the appropriate PA PTT box. PA PTT will close before
the radio PTT (PTT1 and PTT2) by the amount of PTT lead and open after the radio PTT by PA PTT tail
setting.
NOTE: PAPTT tail should be set to provide a few milliseconds of delay after the transceiver PTT
releases. Some transceivers produce RF even after their "amplifier PTT" drops and the delay will prevent
"hot switching on release".
LNA PTT1 & LNA PTT2 are available on the rear panel RCA jacks. They are designed for bypassing low noise
preamplifiers (LNA) or disabling receive antennas during transmit. LNA PTT for each radio is enabled by
checking the LNA PTT box. LNA PTT will close before the radio PTT (PTT1 and PTT2) by the amount of
PTT lead and open after the radio PTT by LNA PTT tail setting.
MK2R can independently select the active PTT output for each radio based on the mode reported by the
transceiver. If Router is not able to read the operating mode from your radio (radio does not have computer
control port or does not report usable mode information), you can select one of four fixed "no radio" modes
or one "no radio" mode with manual (keyboard/keypad) mode selection.
Router groups operating modes into three classes: CW, Voice (USB, LSB, AM and FM) and FSK/DIGITAL. The
available PTT options are:
CW:
PTT1 (microphone jack),
QSK (no transceiver PTT, PA PTT and LNA PTT include only PA/LNA PTT tail)
Semi Break-in (no transceiver PTT, PA PTT and LNA PTT include PTT tail and PA/LNA PTT tail)
PTT2 (rear panel jack).
VOICE:
PTT1 (microphone jack)
PTT2 (rear panel jack).
FSK/DIGITAL:
PTT1 (microphone jack),
PTT2 (rear panel jack),
PTT1 & PTT2 (both jacks).
PA PTT and LNA PTT can be enabled independently for each radio.
CW in VOICE: Enables CW output in Voice modes. Please note, this function must be supported by transceiver.
CW in Voice always operates without transceiver PTT (Semi Break-in).
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