Message-ID: <CA69F6F4C5964E109F95574AECFF3F41@AGB>
From: "Graham" <g8fzk@g8fzk.fsnet.co.uk>
To: <rsgb_lf_group@blacksheep.org>
References: <201204261210.q3QCApb8010726@vivaldi47.register.it>
In-Reply-To: <201204261210.q3QCApb8010726@vivaldi47.register.it>
Date: Thu, 26 Apr 2012 13:49:32 +0100
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Subject: Re: LF: info about better digital mode in 2200m band
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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" <a.dellimmagine@dp-engineering.it>
Sent: Thursday, April 26, 2012 1:10 PM
To: <rsgb_lf_group@blacksheep.org>
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: ik1wvq@stmb.it
>>To: rsgb_lf_group@blacksheep.org
>>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 ...
>>
>>
>>
>>
>
>