New release of MULTIPSK

Patrick Lindecker F6CTE has made available the latest version of his popular data mode software MULTIPSK 4.5

He writes:

The new release of MULTIPSK (4.5), CLOCK (1.7.6) and MULTIDEM (2.1.1) are in my Web site http://f6cte.free.fr/

The main mirror site is Earl's, N8KBR: http://multipsk.eqth.info/index.html (click on "United States"). Another mirror site is Terry's: http://www.hamshack.co.uk/

Multispk associated to Clock are freeware programs but with functions submitted to a licence (by user key).

CLOCK 1.7.6 has now a possibility to directly interface a SdR receiver through the sound card.

MULTIDEM 2.1.1 fixes bugs.

The main modifications of MULTIPSK 4.5 are the following:

1) Decoding/coding of the DTMF (Dual-tone multi-frequency) mode.

This mode is used for telephone (to dial the phone number) but also in VHF and UHF for different uses as, for example, activation of repeaters by radio. It could be used in HF, for radio control of ham radio equipment.

Functions of DTMF handling on reception are available for licenced copies only. See specifications further on.

2) New ALE400 mode (ALE in a 400 Hz bandwidth)

This ALE system has exactly the same functions as the ones of the "141A" of Multipsk except that:

• the bandwidth is 400 Hz instead of 2000 Hz as in standard ALE (so ALE400 can be transmitted anywhere where 500 Hz digital modes are authorized),
• the modulation speed is 50 bauds instead of 125 bauds and consequently the text throughput are 2.5 slower,
• no fix frequency (as in MFSK16...), the automatic tuning being able to be done thanks to the RS/ID transmission,
• the signal to noise ratio is 5 dB better:

- 9 dB for sounding, AMD messages and Unproto mode,
- 11.5 dB (- 13.5 dB with many repetitions) for ARQ FAE.

For ARQ FAE, it has been added a compression system using a modified IZ8BLY (Nino) MFSK Varicode. So the ALE400 text throughput is typically 60 wpm (up to 107 wpm in bilateral and 63 characters frames). ARQ FAE covers all ASCII and ANSI characters (8 bits)

There is a Word document which goal is to show from Multipsk snapshots how to do the basic operations in ALE and ALE400. This document (1.1 Mo) is available from my site http://f6cte.free.fr/ALE_and_ALE400_easy_with_Multipsk.doc

Look also at http://hflink.com/ale400/ which is a specific page for ALE400, with a lot of information.

ALE400 frequencies: 1837.0, 3589.0, 7037.5, 10141.5, 14074.0, 14094.0, 18104.5, 21094.0, 24926.0, 28146.0, 50162.5, 144162.5 (AF at 1625 Hz).

3) Direct SdR interface through the sound card

It is the best way to do as there is no additional transmission delay. It allows the working in all digital modes. The modulation and demodulation operations of the I/Q signals coming from the sound card are directly done by Multipsk (which plays the role of a SdR program).

The bandwidth considered is the USB side, in base band. So there is neither frequency shift nor consideration of the LSB side. After selection, the working is transparent for the user.

4) Rewind function

This function makes you able to decode the signal from a point in time located before you click on the waterfall. It is permitted to select a rewind duration from 5 seconds to 3 minutes (from 20 seconds to 3 minutes for only the licenced copies). Powerful computers can take profit of this function, decoding of the rewind period being quick.

For information, for all the Multipsk exotic modes (PSKFEC31, PSK10, PSKAM, PSK63F, PSK220F (+DIGISSTV), CCW-FSK, MFSK8, THROBX, DominoF, DominoEX, PAX, CHIP, Voice, Packet 110 bauds...), I propose the QRP frequency: 14075 KHz USB (AF around 1000 Hz), at 17h00 UTC.

73

Patrick Lindecker F6CTE