I know for sure that lentus and K1JT's modes are comparable.
They both use the "stadard" definition: signal power/noise power over 2500Hz
band/signal
In my mind roughly : Opera2=WSPR, Opera8=WSPR-6db, Opera32=WSPR-12db
Do you think it's correct?
Opera2=WSPR states that Opera il less efficient (same period for less
information). But Opera don't require any kind of syncronization.
LENTUS = WSPR - 7db For me it's reasonable (same information, more time to
trasmit it, no pseudo-random sequence for syncronization, less "code gain" but
more "symbol" gain)
OK, making comparisons is not so easy... maybe also my conclusions are
discutable
I5ZPO / IW5BHY Andrea
>----- Original Message -----
>From: [email protected]
>To: [email protected]
>Data: Thu, 26 Apr 2012 13:49:32 +0100
>Subject: Re: LF: info about better digital mode in 2200m band
>Just one or two thing's to check
>
>The S/N readings produced by Opera are referenced to the SIM - PATH
>software , so s/n levels shown are calibrated to a different standard
>
>The original system was calibrated to be similar to fldigi / wspr , but
>after a series of tests by members of the yahoo digital group, Jose
>, felt these levels where not realistic and re calibrated , giving a
>lesser reading. Im not sure as what Patrick has referenced his modes
>to, but if lentus system is similar to jt65 etc , then you will need
>to add a conversion factor.
>
>As a yard stick , OP2 @ -26dB S/N is similar to WSPR,
>
>Also note the Op s/n levels are all indicated as Average , over
>the time line , so if you only decode 50% of the transmission
>(sufficient for decode) then the s/n level will show as -3dB compared
>to 100% decode
>
>The Opera system has also a QSO mode using the same coding
>system, but is set to 120 second TX period for 15 characters
>and operates round the -20 dB s/n level
>
>Set Op to 500 Khz for access to the qso mode if wanting to try, but
>you do need -20 dB s/n for decode,
>
>ROS-MF7&2 mode is available ,multi tone, 99Hz b/w at 2 baud , this
>operates at the same S/N of WSPR , but needs AUDIO/SDR Tx
>facility. however it is a live rtty mode with no 'time frame' or 'time
>locking' MF-7 is 6 / 7 dB less, but has a chr rate similar to
>psk31....
>
>73 -G..
>
>
>>>>The OP system is still under development , so if users have any
>>>>requirements etc , pls write in<<<
>
>
>--------------------------------------------------
>From: "DP engineering" <[email protected]>
>Sent: Thursday, April 26, 2012 1:10 PM
>To: <[email protected]>
>Subject: Re: LF: info about better digital mode in 2200m band
>
>> Hi Mauro,
>> At the present, I think Opera is the most widely used.
>> WSPR reaches -27db, not enough for covering long distances on LF. So, it's
>> rarely used.
>> Opera and lentus perform better:
>> Lentus reaches -34db for 5 minutes trasmission, Opera8 and Opera32 (8/32
>> minutes trasmission) reach -32db and -38db respectively.
>> In my opinion, technically speaking, Lentus is the best (it is also very
>> good for making QSO). Lentus requires a very good syncronization among
>> station. In addition, if you use a SDR, you may have some problems due to
>> the latency of the SDR.
>> Instead, Opera is very simple and very close to the "regular" QRSS.
>>
>> So, my conclusions are:
>>
>> For medium distance beacons : Opera8 or Lentus
>> Foe long distance beacons : Opera32
>> For QSO : Lentus
>>
>> best 73's'
>> I5ZPO Gino (operated by IW5BHY Andrea)
>>
>>
>>>----- Original Message -----
>>>From: [email protected]
>>>To: [email protected]
>>>Data: Thu, 26 Apr 2012 12:27:27 +0200
>>>Subject: LF: info about better digital mode in 2200m band
>>
>>>Hi,
>>>
>>>what is the better digital mode for starting listening 137 KHz
>>>band as "reverse beacon" (no TX)??
>>>("better" = greater number of active stations in Europe)
>>>
>>>WSPR ?? LENTUS ?? OPERA ??
>>>
>>>what frequency is utilized for those modes ???
>>>
>>>thanks in advance to all ..
>>>
>>>73 de Mauro IK1WVQ
>>>
>>>P.S.: my RX station is : PA0RDT 8 meters over the roof, RACALL 1792
>>>.. not great station at all ..
>>>in QRSS mode the only station what I can receive is the "broadcast
>>>(HI!)" beacon of Stefan DK7FC .. NO OTHER ...
>>>
>>>
>>>
>>>
>>
>>
>
>
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