Vectronics VEC-162 - Manual (Page 7)

VEC-162B MultiReader Instruction Manual
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4. Set the SPEAKER SELECT switch on the back panel to the OUT position. This allows the internal speaker
of the VEC-162 to be used to monitor the incoming CW audio signal.
5. Starting on the higher side of the CW signal, vary the VFO frequency dial on the radio lower in frequency
until both the LOCK and DATA leds are flashing with the incoming CW signal. The LOCK and DATA leds
should be bright and flashing together. If either led is dimly lit, but is still flashing with the other, then
slightly vary the VFO dial until the dim led becomes brighter, but still flashes together with the other. Once
the leds are flashing together with the incoming signal, vary the VFO dial slightly while watching the VEC-
162 display until good CW copy is obtained.
6. Now with the VEC-162 decoding the incoming CW signal, turn the THRESHOLD control counter-clockwise
until the LOCK led “loses” the signal.
7. Fine tune the VFO dial on your radio until the LOCK led once again follows the incoming CW signal.
8. Repeat steps 6 and 7 until you have adjusted the THRESHOLD control to the absolute minimum setting
possible for good CW copy. With the bandwidth now set to the absolute minimum possible, the VEC-162 will
demodulate clean CW signals because the input circuit rejects noise that would otherwise interfere with the
decoding of the incoming signal.
This completes this section on Tuning in a CW Signal. Just keep in mind that there are a couple of things that
you must do to allow sucessful decoding of CW signals:
1. Make sure that the VEC-162 is setup in the CW mode.
2. Be sure to use the THRESHOLD control to help reject any noise that would interfere
with decoding the incoming signal.
TUNING IN RTTY/ASCII/AMTOR FEC SIGNALS
First of all, set the DATA/CW switch on the front panel OUT, to the DATA position. The VEC-162 is
calibrated for optimum RTTY performance with a MARK tone of 2125 Hz and a SPACE tone of either 2295,
2550, 2975 Hz for shifts of 170, 425, and 850 Hz, respectively. Optimum ASCII/AMTOR FEC performance
occurs with a MARK tone of 2125 Hz and a SPACE tone of 2295 Hz for a 170 Hz shift. Vary the frequency dial
on your radio until the LOCK LED is lit constantly. While keeping the LOCK LED lit, vary the frequency until
the DATA LED blinks with the audio tone shifts of the received signal. If the data is garbled, try changing baud
rates or REVERSE mode, or even the SIGNAL SETUP operating mode. This is because RTTY and AMTOR
FEC signals sound alike, and you may be trying to decode RTTY, with the VEC-162 set to the AMTOR FEC
mode, or vice versa.