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Psk-am, Pzvei – Wavecom W-SPECTRA (Automatic Monitoring System) V1.1.0 User Manual

Page 169

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WAVECOM Monitoring System W-SPECTRA, W-SPEED Manual V1.1.0

Transmission Modes

159

Hence adjustment of the center frequency must be accurate.

In contrast to PSK-31, this mode does not use DQPSK modulation.

PSK-AM

PSK-AM is a very narrow-band and reliable amateur mode developed by F6CTE. The aim of this experi-
mental slow mode is to allow chat communication between hams.

Parameter

Value

Frequency range

HF

Operation modes

Simplex

Modulation

DBPSK

Symbol rate

10, 31.25 and 50 Bd

Receiver settings

DATA, CW, LSB or USB

Input format(s)

AF, IF

Additional Info

14.075 MHz

PSK-AM is similar to PSK-31, but uses its own fixed length 8 bit alphabet with a 5:3 ratio. Each character
is repeated 5 positions later. This diversity in time allows the correction of an invalid character.

Bitstream:

D(x)

R(x-2)

D(x+1)

R(x-1)

D(x+2)

R(x)

D(x+3)

D(x): character

R(x): repeated character

PZVEI

The entire call number is transmitted by consecutive tones in decade sequence. When two identical digits
are to be transmitted consecutively, then an eleventh frequency is used as a repetition identifier.

Parameter

Value

Frequency range

VHF/UHF

Operation modes

Analogue Selcal

Modulation

FM, SUB tone

Receiver settings

FM, BW = 12 kHz

Input format(s)

AF, IF

If more than two identical digits are to be transmitted, the repetition tone is appended to the digit tone
(e.g., 22222 is transmitted as f2 fw f2 fw f2, where f2 is the tone for "2" and fw is the repetition tone).

In most systems the accuracy of the single frequencies has to be within +1/-1.5% of the nominal value.

For ZVEI modes having nominal tone durations of 70 ms, the duration of a single tone may vary ± 15 ms.

Decoding the selective calls is started by clicking on a system. If transmission and system selection con-
form, the call sign is displayed on the monitor. In the Options menu a Time stamp function can be ena-
bled to add date and time to each call.

Tone Allocation

Digit

Hz

Digit

Hz

0

2400

8

2000

1

1060

9

2200