7
6 – DECODING WHEN RECEIVING TELEGRAPH
1) Set the desired reception sound volume with the AF control of the receiver.
2) If your receiver set is equipped with a CW filter, make the CW filter effective.
3) If your receiver is equipped with IF shift control, pass band tuner or notch filter, set the peak
reception volume at the frequency of 800 Hz.
4) Set the TONE control knob of the CWR-880 at the center position and tune the receiver to re-
ceive 800 Hz signal. CW LED will flicker in synchronization with the reception sound and de-
coded characters will be shown on the display monitor. If the CW LED does not flicker in syn-
chronization with the reception sound, decoding is not done normally; tune the receiver again
or make fine adjustment with the TONE knob.
7 – DECODING WHEN RECEIVING RTTY
* Teletype for amateur radio station
1) When the CW/RTTY selector of the CWR-880 is set to RTTY, a message "BAUDOT SPEED 45b
NOR" appears on the display, which shows that the reception with an amateur radio station is
enabled. Place the TONE VR knob at the position "HIGH" and set the receiver in LSB or FSK
mode. Turn the receiver tuning dial gradually from the position of lower beat to that of higher
beat. First the MARK LED flickers. Tuning the dial further to higher position (shifting by 170
Hz), the MARK LED and SPACE LED will flicker with correct decoding started. Flickering of only
the SPACE LED indicates improper tuning. In such a case tune the receiver again or adjust the
TONE VR finely to make the MARK LED also flicker.
2) When the received characters are changed to numerical figures or symbols due to noise or oth-
er interference during reception of ordinary alphabetical characters, set the USOS switch in ON
position and normal alphabet will be obtained when space signal is received.
3) LTR/FIG switch is to changeover between alphabet and numeral every time it is pressed. When
alphabet is changed to numeral due to noise or other interference, press this switch to obtain
the normal decoding.
4) Set the NOR/REV switch to REV to receive signals of reverse shift. Reverse shift is obtained al-
so when receiving from KEY IN (TTL IN).
* Teletype in commercial station
While setting procedures for teletype in commercial station are almost the same as those of
amateur station, the receiver mode is to be set to USB. As the transmission speed of 50 baud
is widely used, set the SPEED to 50b. Since some stations transmit at 57 or 75 baud, try these
speeds if normal decoding is not obtained. Signals from many unidentified stations cannot be
decoded at all. Because signals from commercial stations have wide shift width, tuning is easier
than amateur station.
* Teletype of TOR system
TOR system teletype is equipped with automatic error correction function which corrects a mis-
received character automatically. Intermittent reception sound like "chee chee chee" is given in
