Message-ID: <3A4D90749A2B4138B1217645ED8CA931@GaryPC>
From: "Gary G4WGT" <g4wgt@tiscali.co.uk>
To: <rsgb_lf_group@blacksheep.org>
References: <000a01cd1632$797db5f0$6c7921d0$@fr> <4F82C56B.8060900@broadpark.no> <87B6713738004650B13893BB874CBF8B@GaryPC> <4F82F7CB.6010907@broadpark.no>
In-Reply-To: <4F82F7CB.6010907@broadpark.no>
Date: Mon, 9 Apr 2012 16:32:34 +0100
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Subject: Re: LF: Re: New release (4.21) of MULTIPSK
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Hi Steinar,

Also I have just (1530utc) increased power to 20mW ERP.

Gary - G4WGT.

----- Original Message ----- 
From: "Steinar Aanesland" <saanes@broadpark.no>
To: <rsgb_lf_group@blacksheep.org>
Sent: Monday, April 09, 2012 3:52 PM
Subject: Re: LF: Re: New release (4.21) of MULTIPSK


Gary , it is possible for you to run a 0,5,10,15 beacon interval? 15
minutes is a long time to wait ;)

la5vna S






Den 09.04.2012 14:16, skrev Gary G4WGT:
> Hi Steinar, LF,
>
> Lentus QRP beacon now running on 136.300kHz USB dial (1000Hz audio =
> 137.300kHz).
>
> 15 minute beacon period started at 1205utc.
>
> 73, Gary - G4WGT.
>
> ----- Original Message ----- From: "Steinar Aanesland"
> <saanes@broadpark.no>
> To: <rsgb_lf_group@blacksheep.org>
> Sent: Monday, April 09, 2012 12:18 PM
> Subject: LF: New release (4.21) of MULTIPSK
>
>
> Hi all of you that like to try LENTUS on LF.
>
> The beta testing is over . Here is the latest multipsk release with the
> new mode Lentus is included.
>
> http://f6cte.free.fr
>
> This mode is used for QRP transmissions  (down to a minimum S/N ratio of
> -34 dB) either in LF, MF and HF (14 MHz maximum) but not beyond.
>
> The recommended frequencies (on the XCVR) are the following (with an AF
> frequency of 1000 Hz, in USB): 136.3, 1837.0, 3589.0, 7037.5, 10138.7,
> 14074.0, 14095.6 KHz.
>
>
> *LENTUS*
>
> LENTUS means " Slow " (but also indolent, nonchalant, quiet…) in latin.
> _Created by_: Patrick Lindecker (F6CTE) in 2012
>
> *Description :*
>
> _Baud rate_: 0.1465 (4800/32768) or 6.827 seconds by 5 bits symbol
>
> _Messages_: a message of 293.5 seconds duration (43 symbols) begins at
> t=4 sec of the UTC minute 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, or
> 55 (it is necessary that the PC may be synchronized on a “Standard” 
> clock).
>
> _Note_ : in manual transmission, it can also start at 4+6.827=10.827 sec
> (42 symbols sent) or 10.827+6.827=17.654 sec (41 symbols sent) or
> 17.654+6.827=24.481 sec (40 symbols sent), to « pardon » the Ham
> operator for a delay to answer, but with reception probability a bit
> weaker.
>
> The message is normally composed of 43 symbols (but can be reduced to 40
> symbols, see above), each one with a length of 32768 audio samples (or
> or 6.827 seconds). The 9 first symbols carry a tone allowing the
> determination of the transmission central frequency. The 31 following "5
> bits symbols" carry the message (allowing the Reed-Solomon coding of 75
> bits). The last three symbols are transmission central frequency carriers.
>
> Messages can be either plain text (13 characters, preceded by a bit “CQ
> de” and a bit “Beacon”) or formatted text according to different
> possibilities, listed below:
>
> ·    _A standard CQ call_composed of a bit “CQ” + a bit “Beacon” +
> complete call (with 3 characters max in the mantissa, as for example
> “AZ2/FL5XYZ/MM”) + optionally, a 6 characters Locator (accuracy +/-2.31
> km in latitude and +/- 4.63 km in longitude).
> Note: without the “CQ”, it is an information transmitted by the Ham
> answering to the CQ call,
>
> ·    _A “Station description”  type CQ call _composed of a bit “CQ” + a
> bit “Beacon”, a 6 characters call + suffix (as for example “FL5XYZ/MM”),
> a “6 characters Locator” + Power level + “mW/W” bit + relative gain of
> HF antenna + directivity of the antenna.
> Note: without the “CQ”, it is an information transmitted by the Ham
> answering to the CQ call,
>
> ·    _A “Meteorological”  type CQ call _composed of a bit “CQ” + a bit
> “Beacon”, a 6 characters call (as for example “FL5XYZ”), a “6 characters
> Locator” + Temperature + Wind force + Type of weather + Humidity.
> Note: without the “CQ”, it is information transmitted by the Ham
> answering to the CQ call,
>
> ·    _A CQ call with precise geographical position_composed of a bit
> “CQ” + a bit “Beacon”, a 6 characters call + a geographical position
> (latitude + longitude) in ° ‘ and 2 figures decimal (as for example
> “48-49.83N 002-22.02E”). The accuracy is equal to 9 m in latitude and in
> longitude (about 60000 times more precise than a Locator position).
> Note: without the “CQ”, it is an information transmitted by the Ham
> answering to the CQ call,
>
> ·    _An answer to a CQ with Locator 4 characters _composed of a 6
> characters Call 1 ( as for example “FL5XYZ”) + 6 characters Call 2 (as
> for example “FL5XYZ”) + Locator 4 characters  (accuracy +/-55 km in
> latitude and +/- 111 km in longitude), in answer of Call 1 to a CQ done
> by Call 2,
>
> ·    _An answer to a CQ with S/N ratio and drift _composed of a 6
> characters Call1 (as for example “FL5XYZ”) + 6 characters Call 2 +
> Suffix (as for example “FL5XYZ/MM”) + S/N ratio (12 to -37 dB) + drift
> (-4 to 4 by step of  0.1 Hz/mn), in answer of Call 1 to a CQ done by
> Call 2,
>
> ·    _An answer to finish a QSO_composed of a 6 characters Call 1 (as
> for example “FL5XYZ”) + 6 characters Call 2 + Suffix (as for example
> “FL5XYZ/MM”) + “73 GB SK”.
>
> _Moments of decoding :_
>
> _Reception start_: the reception normally begins at t=4 sec and lasts 40
> or 43 symbols (see below). In case of failure of the operator, the
> reception can also begin at t=24.481 sec and lasts 37 or 40 symbols
> (it’s a degraded working).
>
> _Decoding start_: the main decoding takes place after reception of 40
> symbols (i.e. 273 seconds), which normally leaves about 25 seconds to
> answer. However, there is still a margin of 20 seconds (to reach
> 25+20=45 sec), the message being, in that case, truncated but being able
> to be decoded.
>
> In case of failure of the main decoding, other decoding attempts are
> done after 41 symbols (280 seconds), 42 symbols (287 seconds) and 43
> symbols (294 seconds). In this last case, it remains 6 seconds to
> answer. However, there is still a margin of 20 seconds (to reach 6+20=26
> sec), the message being, in that case, truncated but being able to be
> decoded.
>
> _Mode of transmission_: Lentus can be used to do QSO (two_way
> communication) or as a beacon. In that last case, no answer is required:
>
> ·    a beacon transmission  could be done at minutes 0, 5, 10, 15, 20,
> 25, 30, 35, 40, 45, 50, or 55.
>
> ·    for a QSO, by mutual agreement , the Ham calling CQ will transmit
> at minutes 0, 10, 20, 30, 40, 50 and the Ham answering to the CQ call
> will transmit at minutes 5, 15, 25, 35, 45, 55.
>
> _Repeater_: Lentus can also be used, for very specific use, as a
> repeater. As a repeater, it simply transmits  what it is received so as
> to forward the message to other stations or to broadcast a message (with
> several repeaters).
>
> _Speed_ : 75 bits (or 13 characters maximum in plain text) by 5  minutes
> period (with only one message by period) or 0,43 wpm
>
> _Modulation_ : MFSK 32 tones (for 5 bits) with a shift between tones of
> 0.7325 Hz (5 x baud rate).
>
> The synchronization tone transmitted during the 9 first symbols
> corresponds to the central frequency of the transmission bandwidth. It
> permits to determine this frequency (with a precision of about +/- 0.1
> Hz) and the drift speed (up to 3 Hz/mn). The 32 possible 10^th symbol
> (first data) frequencies will be estimated from these two pieces of
> information. The synchronization frequency search bandwidth tolerance is
> variable from +/- 20 Hz to +/-80 Hz, counted from the frequency clicked,
> by the user, on the waterfall.
>
> _Receive mode_: USB. Each transmitting or receive period of 300 sec must
> start at t=4 sec of the UTC minute 0, 5, 10, 15, 20, 25, 30, 35, 40, 45,
> 50, or 55 with a maximum tolerance of +/-0.1 sec of the PC clock. A
> margin of 20 seconds is given as indicated in “Messages” above.
>
> It is possible to introduce an advance (from 0 to 0.1 second by 10 msec
> steps) to compensate from a possible transmission delay (due to a big
> distance to the zone to target or a delay due to a Wifi link, for
> example). Symmetrically, in reception, this advance will be taken into
> account as a delay to start decoding.
>
> The time to switch the transceiver is supposed to be very short
> (definitely less than to 100 ms).
>
> _Characters set_(46) : ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 <SPACE> / +
> - . ? ! @ % $
>
> _Shape of pulse_ : rectangular
>
> _Bandwidth_: 23 Hz
>
> _Synchronization:_using the very accurate time from an Internet Time
> Service as the NSIT, through a SNTP or NTP protocol (but not through the
> RFC-868 Time Protocol) so to have an accuracy widely better than 50 ms.
> The use of the “AboutTime” freeware is widely encouraged as the PC time
> error is determined by the soft, simply by setting time twice, the
> second time (and the followings) will give the PC time error.
>
> _Coding code_: Reed Solomon (31, 15) or 31 symbols of 5 bits for 15
> symbols of 5 information bits (so a yield of 0.48). The irreducible
> polynomial P(x) is equal to X^5+X^2+1.
> The generator polynomial G(x) is equal to a product of (X+alpha^i) with
> i minimum=1.
>
> _Convolution code_: no
>
> _Interleaving_ : no interleaving nor Gray coding is used.
>
> _Scrambling_ : each of the 31 Reed-Solomon symbols (which value is
> between V=0 and V=31), which order is defined by O=0 for the first
> transmitted symbol until O=30 for the last transmitted symbol, is
> associated with a XOR f(O). In other words, for each symbol, it is done
> the operation V = V XOR f(O). This is done to avoid that a carrier
> produces a suite of same symbols (suite which could be interpretable by
> the Reed Solomon coding as a correct code). At reception, the V initial
> is found again by doing Vinitial = Vreceived XOR f(O). The f(O) function
> is random.
>
> _Pmean/Ppeak_: 1
>
> _Drift tolerance_ : 2 Hz/mn (note that the performance in S/N ratio term
> is degrading with drift)
>
> _Lowest S/N_: -34 dB (without any drift, for more than 90 % of the
> frames), however  some frames are decoded at -36.5 dB. At -37 dB and
> below, no frames are decoded.
>
> Specifications of this mode will be found in the document
> "Specifications 1.0 of the Lentus mode"  written the 10th of March 2012
> ("Specifications" on my WEB site: http://f6cte.free.fr/).
>
>
>
> ----------------
>
>
> 73 and good LENTUSING from LA5VNA Steinar
>
>
>
>
>
>
>
>
>