I have a modulation mode:

  • (to be used for a satellite)
  • (of a series of AX.25 frames)
  • (in the 70 cm band)
  • 9.6 kbps
  • Ideally BPSK or QPSK modulation
  • but could be plain FM

Which I need to describe with an abbreviation from the table of modes recognised by our amateur radio regulator (in South Africa):

Table of mode descriptions

I suppose the same would apply to all packet radio operation, really.
Which mode fits best?


3 Answers 3


After a bit of google:

It seems J2D describes this mode best. The ITU says in this workshop document that J2D is

Single-sideband, suppressed carrier with single channel containing quantized or digital information for data transmission

Wikipedia has a more detailed table from which we could construct new mode names, G1B or G1D,

  • G (phase modulation)
  • 1 (single channel containing digital information, no subcarrier)
  • B (Electronic telegraphy, intended to be decoded by machine (radioteletype and digital modes))
  • D Data transmission, telemetry or telecommand (remote control)

For digital modulation, I'm not sure it's worth separating Phase modulation from Frequency modulation.


You can figure it out yourself using this wiki

Example: BPSK or QPSK would be J2B


The other answer given is J2D or G1B / G1D, which is specifically for Data, and I must agree that is probably a better type indication.

This is totally dependent on how your protocol is structured, I guess.


In our national frequency plan, sub bands reserved for digital data, including packet radio are marked as dedicated for modes A1D, A2D, F1D, F2D, J2D

A Amplitude modulation

F Frequency modulation

J SSB modulation

1 One channel containing digital information, no subcarrier

2 One channel containing digital information, using a subcarrier

D Data transmission

  • 1
    $\begingroup$ Could you provide a reference? $\endgroup$
    – rclocher3
    Aug 16, 2016 at 21:21
  • $\begingroup$ I could lot properly format text in comment so i updated answer. $\endgroup$ Aug 17, 2016 at 7:03

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