User guide

MS-DMT Guide v1.04

Released 05-30-2014

MODEM

At present the Modem selection pull down is disabled as the MS110A modem is the only

selection, however that will change in the future when S4285 will likely be the next selection.

PSK CARRIER

The PSK carrier selections provided will follow the mode selected as additional modes selections

become available. For the MS110A ST waveform the 1800Hz selection is the standard PSK

carrier and the default for MS110A in the software. The 1650Hz and 1500Hz selections have

been provided for MS110A as optional non-standard selections as they are supported in many

hardware modems for MS110A.

All stations must either make use of the same PSK carrier or offset tune their frequency based

on the difference between the PSK carrier that they are using and what has been directed for

use on the given frequency. If either is not the case, the PSK carriers will not be aligned and

communications will not occur.

The use of 1500Hz supports maximum use of narrow SSB filters that don’t meet S4203, its use is

recommended for use during broadcast message reception and all digital net operation ONLY

and not in mix Voice/DATA nets.

The use of data rates higher than 600bps is dependent on the TX station IF passband filtering. If

not to STANAG 4203 requirements, the higher data rates will be negatively impacted on TX and

thus also on RX, especially when using the 1800Hz PSK carrier. Using a 1500Hz PSK carrier on TX

places more of the 300-3300Hz ST waveform into the passband of IF filters that don’t meet

S4203 which improves the use of higher data rates when the TX frequency is offset to align with

users of the standard 1800Hz PSK carrier. Likewise, if stations are using 1500Hz on RX their filter

will pass more of the waveform for reception and decoding.

CAT Com Port

By default CAT serial support is OFF, this is achieved by setting the CAT com port to 0. To make

use of CAT a com port between 1..16 must be entered. The com port parameters are user

selectable for baud rate and framing if other than the default values for each radio type selected