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MFJ-1278B MULTI-MODE BASIC OPERATION
THE MFJ-1278B MULTI-MODE MODEM
The MFJ-1278B modem has five sets of pre-set modem components. These modem
components allow the MFJ-1278B to operate efficiently in its various modes of operation.
These modes of operation include VHF and HF Packet, PACTOR, AMTOR, VHF RTTY,
HF RTTY, VHF ASCII, HF ASCII, CW, Modulated CW, CW Memory Keyer, 16 gray level
FAX (including Weather FAX), color SSTV and monitoring of NAVTEX.
All modem components have been individually calibrated for each mode of operation. The
MFJ-1278B has been factory calibrated and does not require re-calibration when operating
any the operational modes.
The modes used with each modem are shown in Table 4-1. The tones and shifts produced by
each modem are shown in Table 4-2.
MODEM OPERATION MODES
P
VHF Packet, 2 level FAX
H
HF Packet, HF Baudot RTTY, HF ASCII, PACTOR,
AMTOR, NAVTEX
V
VHF RTTY, VHF ASCII
C
CW, Memory Keyer, Modulated CW
M
Multi-level FAX, Color SSTV
Table 4-1: MFJ-1278B Modem and Operation Modes
MODEM LOW TONE(Hz) HIGH TONE(Hz) SHIFT(Hz)
P
1200 2200 1000
H
2125 2295 170
V
2125 2975 850
V*
1275 1445 170
C
700 ---- ----
M
1100, 1200, 1300, 1500 and
1550 thru 2250 in 50-Hz steps
Table 4-2: Tones & Shifts Produced by the MFJ-1278B Modems.
* The MFJ-1278B will transmit and receive these tones when shorting jumpers for JMP E, F,
G, and H are removed on the mother board.