DRAKE TR270 Owner'S Manual Download Page 33

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5) Monitor the frequency prior to actually transmitting to
ensure that there is no interference with others trying to
use the repeater.
6) Press and hold the PTT button on the microphone and
speak into the microphone at a normal voice level. The
display will change to indicate the transmit frequency.
7) Release the PTT button when you are finished speak-
ing to return the TR270 to the receive mode.

SUBAUDIBLE TONE OPERATION

The TR270 includes a subaudible encoder/decoder for
transceiver ‘A’ and a separate decoder for receiver ‘B’.
‘A’ and ‘B’ tone frequencies may be set independently
of each other. ‘A’ may be set to encode only, or to
encode and decode. Encoding only will be used when
you need to transmit the tone to open the subaudible
squelch of a repeater or of any other receiver with sub-
audible tone squelch activated, but you wish to hear
any signals that exceed the signal level threshold set by
the squelch control. If you desire the TR270 to only
respond to signals transmitting a subaudible tone, the
decode function may be activated as well. The status
of the encoder and decoder for transceiver ‘A’ is always
shown on the LCD display. To see the status of the

decoder for receiver ‘B’, press the

CTS

button once

when the ‘B’ receiver is selected for tuning.

If the TR270 is used frequently for receiving signals that
are transmitting continuous subaudible tones, it may be
desirable to reduce the level of the tone heard in the
speaker by enabling a high pass filter. Program SETUP
#59 for a ‘1’ to enable the filter for receiver ‘A’; program
SETUP #60 for a ‘1’ to enable the filter for receiver ‘B’. In
the repeat mode, program SETUP #57 for a ‘1’ to enable
a high pass filter in the audio path. Finally, if you are
using CTCSS encoding, and the receiving station
experiences “talk off” (squelching on voice peaks),
program SETUP #58 for a ‘1’ to enable a high pass filter
for the microphone audio. All of these high pass filters
have a cutoff frequency of approximately 300 Hz.
Expect some noticeable loss of low frequency audio
response if the filters are enabled.

Transceiver ‘A’ -

To Enable Tone Encode and /or Tone Encode/Decode:
Press the

A / B

button to select receiver ‘A’, if necessary.

1) Press the

CTS

button once, and within 3 seconds,

2) Dial in the desired subaudible tone frequency, using
the main tuning wheel.
3) With the tone frequency displayed, press the

CTS

button again to enable tone ENCode.

4) Press the

CTS

button again to enable tone ENCode/

DECode.

5) Press the

CTS

button again to turn the tone Off.

28 Voice Operation, continued

Receiver ‘B’ -

To Enable or Disable Tone Decoding:
Press the

A / B

button to select receiver ‘B’, if necessary.

1) Press the

CTS

button once to see the present setting

(‘OFF’ indicates that the decoder is disabled), and
within 3 seconds,

2) Rotate the tuning wheel or press

buttons to set

the desired tone frequency. Allow display to time out.
The encoder is now enabled.

Press the

CTS

button at any time to review the current

setting. Press the

CTS

button a second time before the

display times out to toggle between on (tone frequency
displayed) or ‘OFF’ without changing the programmed
decode frequency.

Subaudible Tone Table:

DTMF OPERATION

Some repeaters use DTMF (Touch Tone ®) for control
purposes and to allow users of the repeater to make
telephone calls (Autopatch) through the repeater. The
TR270 is capable of generating DTMF tones for this
purpose.

DTMF Tone Table:

FREQUENCY (Hz) 1209 1336 1477 1633

697

770

852

941

The DTMF tones are available anytime the TR270 PTT is
pressed.

TO USE DTMF TONES

1) Press PTT on the microphone.
2) Press buttons 0-9, A-D, or *, #.
The microphone audio is muted during the time each
button is held.

The TR270 permits up to ten, 14-digit DTMF sequences to
be programmed and stored in memory. Additionally,
two methods of dialing are available.

Nominal Tone Frequency (Hz)

67.0
69.3
71.9
74.4
77.0
79.7
82.5
85.4
88.5
91.5