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16 MFSK 64 HZ B/W Plain text EME mode #eme

Graham
 
Edited

16 MFSK  64 HZ B/W   Plain text  EME mode 1 Baud 
While  routing  round  for a  ROS version that  was compatible  with  6-9-0
and finding  6-9-1  is compatible,   the  version change was adding the  compatibility
routine   to  enable other  app's like  'spec lab'  to  run, without 
altering the  performance ,  I noticed , as well  as the  discontinued
500 Hz  B/W Hf mode the  version  contains the  EME mode , as well
as the  mf2 and mf7 modes ,  making  5 systems  in the  one package 

Quite  how it was  missed by  the  EME user's  , 
but  at  64 Hz   on air bandwidth  16 tone mfsk ,
it  offers   a plain text chat mode over the  eme path  , 
using  very little  space,  the  comment  on the  path,
indicates , that  narrow  systems are suitable ..

A novel  facility is the  search  , allowing  reception  if
the  signal is  over +/-  ! KHz  from the  center to correct
for  doppler 

Works as   qrp mode  on  MF equally  as  well
at -35 dB s/n   

73-Graham
G0NBD

Extract  from the  user  info 
ROS EME

  Is a mode designed for Moon Bounce communications. The communication channel in this modality is quite different from that of HF, and the frequency diversity systems don't provide any significant advantage. That's why the modulation system used is the classic 16-tone MFSK.

 To ensure a better orthogonality the tones have been separated by 4Hz, a more than sufficient amount, to achieve a 64Hz bandwidth.

 The slender bandwidth required by this modulation allows us to perform automatic frequency scanning of up to ±1300Hz, very useful to detect Doppler shift when working Moon Bounce on 70cm.

 The symbol rate is 1 baud, being a mode that also decodes in real time, allowing the asynchronous Moon Bounce communication as well. It can decode signals of up to –35dBs over noise AWGN.

 In addition, ROS EME uses an initial synchronism sequence that allows detecting the received signal's Doppler shift and subsequently starting to decode in real time.

 ROS HF, as well as ROS EME use as FEC the popular convolutional code R=1/2, K=7 NASA Standard.

 This software sends automatically ***reports to the operators who include their email address in any of their messages. The reports include reception conditions and information about the receiving station. More details on this manual. 

NOTE :-

 *** This  refers to the  auto  report option, that  emails directly  to  a decoded e-mail  address , an  example

[Fade Marge: +22 dB  = Im running  about  20 dB  too much power for the link ]

 

********** Please do not reply to this email ********************

 

 

 

OE7DMT has received your Radio Message sent at: 21:29 UTC

Message Received: Report: OE7DMT de G0NBD  S/N: -4 dB, Marge: +12 dB  g0nbd@... (BRM)  <CRC-OK>

Operator Info:

Callsign: OE7DMT

DXCC: Austria (EU)

Name: Dirk

E-mail: mail@...

QTH: Tirol / Kirchbichl

Locator: JN67bm

Station: TRX :IC-7300 /Ant. Dipol / Power 30 W ROS Version: ROS v7.4.0

Signal Info:

Frequency: 7,048 Mhz

Mode: ROS4/2000

Symbol Rate: 4 Bauds

Frame Acquisition: 22/24

Final Acquisition: 14/16

Frequency Shift: 0,0 Hz

Viterbi: 4%

S/N (2500 Hz): +0 dB, Fade Marge: +22 dB

Distance: 1254 km, Azimuth: 127

Beacon: OFF

Vumeter Level: -27 dB

CPU Usage: 33 %

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