MIME-Version: 1.0
In-Reply-To: <0AEB27EC926949C9B32EE63FA61DB68A@AGB>
References: <CAHAQVWPuaRx6ET1ECQaF0kANTpYF6GcaaOh0oFZsnfuFEvfk7w@mail.gmail.com>
	<09A1EC98B4A642B39191429716F9579E@AGB>
	<CAHAQVWN0S4cdwYfS8ow=EQZ_ZZLr6Gc=ZeJ_rE4Hr0cfNsmDzw@mail.gmail.com>
	<CAHAQVWNi4AW6JeNBSJ0KT1+x89f5gSk+9r3YAHuZjYK7ENbihg@mail.gmail.com>
	<0AEB27EC926949C9B32EE63FA61DB68A@AGB>
Date: Fri, 6 Jan 2012 21:00:57 +0000
Message-ID: <CAA8k23T9ie32HH+rP-_Gh0DxUy6fzrnNiHb9FCBitHLH-QPKBA@mail.gmail.com>
From: Andy Talbot <andy.g4jnt@gmail.com>
To: rsgb_lf_group@blacksheep.org
Subject: Re: LF: Opera questions
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org
X-AOL-SCOLL-URL_COUNT: 0  
X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d005.2 ; domain : gmail.com DKIM : pass  
x-aol-sid: 3039ac1d60c94f0761490a94
X-AOL-IP: 195.171.43.25
X-AOL-SPF: domain : blacksheep.org SPF : none


Opera 31 has 8 second symbol periods, so has a noise bandwidth of 0.125Hz.
Normalising this -38dB  (in the ref 2500Hz)  to the actual  bandwidth
gives a S/N of +6dB

WSPR and JT4 when normalised in the same way come out at around 3dB
S/N.  Now, assuming that -38dB / +6dB figure is based on the carrier
on period, and not the mean power (which on my measurements is exactly
50% duty cycle) suggests Opera is 3dB lower performing on its raw
decoding over WSJT.   BUT, if the S/N is calculated based on the mean
power, then they are both equal.  But since they are both non-coherent
tone detection modes with strong FEC, that's hardly surprising.

Andy
www.g4jnt.com



On 6 January 2012 20:49, Graham <g8fzk@g8fzk.fsnet.co.uk> wrote:
> That's=A0 ok Roger ..
>
> Rx=A0=A0 speed=A0 is=A0 automatic=A0 .....=A0=A0 the=A0 speed=A0 select=
=A0 is=A0 for=A0 Tx only=A0 -
> mode=A0 select=A0 via=A0 frequency=A0 band
> No=A0=A0 PC time=A0 lock=A0 required=A0 ...its free=A0 running
> OP31 expected=A0 round=A0 -38 dB=A0 s/n=A0 (ave)=A0=A0=A0=A0 OP8=A0=A0 ~=
=A0 -32 dB
>
> G..
>
>
>
> From: Roger Lapthorn
> Sent: Friday, January 06, 2012 8:38 PM
> To: rsgb_lf_group@blacksheep.org
> Subject: Re: LF: Opera questions
>
> Sorry Graham, another Opera question. Does the mode depend on PC timing i=
n
> the same way WSPR does? I think not, but just checking.
>
> 73s
> Roger G3XBM
>
> On 6 January 2012 20:34, Roger Lapthorn <rogerlapthorn@gmail.com> wrote:
>>
>> Thanks Graham.
>>
>> Does the software sort out if it is receiving an Op8 or Op31 transmissio=
n?
>> I.e. if I TX in Op31 do people have to listen in that speed too? I think=
 not
>> as I copied SM6BHZ when my switch was set to Op31.
>>
>> Is it possible to establish the "effective sensitivity" when comparing
>> Opera against WSPR, QRSS3, 30 etc? I am unsure if the bandwidths of the
>> modes in which the S/N is shown for Opera is comparable. If more sensiti=
ve
>> than WSPR or QRSS30 even then this is definitely a very exciting new mod=
e
>> for QRPers like me. It might also be fun for earth mode VLF tests too.
>>
>> 73s
>> Roger G3XBM
>>
>>
>> On 6 January 2012 20:25, Graham <g8fzk@g8fzk.fsnet.co.uk> wrote:
>>>
>>> Ok Roger
>>>
>>> The=A0 tx=A0 time=A0 is=A0 linked to the=A0 mode=A0 name=A0=A0 OP2=A0 =
=3D 2 mins=A0 ,=A0=A0 OP15 =3D
>>> 15 mins=A0=A0 OP8=A0=A0=A0=A0OP31=A0=A0 mins
>>>
>>> Who's=A0 on ?=A0 Yes p possibly , but that=A0 would=A0 need=A0 a=A0 web=
 programmer=A0..
>>> but=A0 its=A0 only=A0 day=A0 6 !
>>>
>>> you=A0 can=A0 check the=A0 PSK Report map=A0 to=A0 see=A0=A0 who=A0 has=
=A0 tx /rx in the
>>> last 15=A0 mins
>>>
>>> A book=A0 would=A0 be handy=A0 as=A0 it looks=A0 like=A0 its=A0 going=
=A0 to=A0 be=A0 popular
>>> , never=A0 seen so=A0 many=A0 beacons=A0 tx/rx =A0on 136 !
>>>
>>> Left hand=A0 screen =3D=A0 local=A0 decodes
>>> Righ=A0 hand=A0 screen=A0 =3D=A0 decodes=A0 distributed over the=A0 web
>>>
>>> Not=A0 forgetting Mr Ros =A0seems to=A0 code=A0 exceedingly=A0 good=A0 =
codes , as
>>> the=A0 advert=A0 says=A0 hi
>>>
>>> 73 -G..
>>>
>>> From: Roger Lapthorn
>>> Sent: Friday, January 06, 2012 8:10 PM
>>> To: rsgb_lf_group@blacksheep.org
>>> Subject: LF: Opera questions
>>>
>>> Somewhere I must have missed some information:
>>>
>>> How long does it take to send a beacon message in Opera8 and Opera31?
>>> Is it possible to have something like the WSPRnet database showing
>>> stations on each band monitoring and TXing? It helps to know someone is
>>> looking!
>>> Can we have a "read me" that explains what is meant to happen on the
>>> screen?
>>>
>>> Tried a brief transmission on 136 into my earth electrodes as my loop
>>> antenna is down without success (so far) but just had my first decode o=
n RX
>>> in Opera8:
>>>
>>> 20:07=A0 SM6BHZ 136 Op8 -19 dB 951 km @ 046=A0 - not bad for 2 ground r=
ods
>>> and no antenna!
>>>
>>> 73s and thanks for this interesting new mode Graham.
>>>
>>> Roger G3XBM
>>>
>>>
>>> --
>>> http://qss2.blogspot.com/
>>> http://g3xbm-qrp.blogspot.com/
>>> http://www.g3xbm.co.uk
>>> https://sites.google.com/site/sub9khz/
>>>
>>>
>>
>>
>>
>> --
>> http://qss2.blogspot.com/
>> http://g3xbm-qrp.blogspot.com/
>> http://www.g3xbm.co.uk
>> https://sites.google.com/site/sub9khz/
>>
>>
>
>
>
> --
> http://qss2.blogspot.com/
> http://g3xbm-qrp.blogspot.com/
> http://www.g3xbm.co.uk
> https://sites.google.com/site/sub9khz/
>
>