Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mi02.r1000.mx.aol.com (Internet Inbound) with ESMTP id 204DC38000087; Wed, 24 Oct 2012 19:35:19 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1TRASe-000495-Oo for rs_out_1@blacksheep.org; Thu, 25 Oct 2012 00:34:08 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1TRASe-00048w-3t for rsgb_lf_group@blacksheep.org; Thu, 25 Oct 2012 00:34:08 +0100 Received: from smtpout1.wanadoo.co.uk ([80.12.242.29] helo=smtpout.wanadoo.co.uk) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1TRASb-0002Tu-TF for rsgb_lf_group@blacksheep.org; Thu, 25 Oct 2012 00:34:07 +0100 Received: from AGB ([2.26.47.29]) by mwinf5d12 with ME id FBa41k0070dmnFE03Ba4V8; Thu, 25 Oct 2012 01:34:05 +0200 Message-ID: From: "Graham" To: References: <4084B089A7FF496CAC1CE9A2459B9C47@AGB> <7E9EB5FA653147298EEBB4676DCDD9DD@White> <3DD7F0DC19984F7CBF611D59430EEFA3@AGB> In-Reply-To: Date: Thu, 25 Oct 2012 00:34:04 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 X-Spam-Score: 3.2 (+++) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Yes I remember those tests with Albert , the results where totally different to the local 25 mile tests with the same set up early in the same day . but that's live path testing ... fsk , of course , but simplicity is the object , switching the (led) light off and on could reduce the duty by 50% where heat is a problem , but that is for those who are experimenting in that area , adding a 17 KHz band to the modem simply allows any one to try , with the minimal of effort , at the moment the only path is via conventional translation at 100% carrier , 30 second burst should work on satellite scatter , works fine at 50MHz with aircraft ... I assume the optical link will not have a dopper shift ? [...] Content analysis details: (3.2 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [80.12.242.29 listed in list.dnswl.org] 0.0 HTML_MESSAGE BODY: HTML included in message 3.2 MANY_SPAN_IN_TEXT Many tags embedded within text X-Scan-Signature: e6ca507e494efc41e4b71d154e5805b0 Subject: Re: LF: OPERA OPTICAL BEACON (way off topic) but is based on 17 KHz :) Content-Type: multipart/alternative; boundary="----=_NextPart_000_00BF_01CDB248.6F8F8AC0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.6 required=5.0 tests=HTML_40_50,HTML_MESSAGE, MISSING_OUTLOOK_NAME autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false x-aol-global-disposition: G x-aol-sid: 3039ac1d7b8a50887b370392 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This is a multi-part message in MIME format. ------=_NextPart_000_00BF_01CDB248.6F8F8AC0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Yes I remember those tests with Albert , the results where = totally different to the local 25 mile tests with the same set = up early in the same day . but that's live path testing ... fsk , of course , but simplicity is the object , switching the = (led) light off and on could reduce the duty by 50% where = heat is a problem , but that is for those who are experimenting in = that area , adding a 17 KHz band to the modem simply allows = any one to try , with the minimal of effort , at the moment the = only path is via conventional translation at 100% carrier , 30 = second burst should work on satellite scatter , works fine at = 50MHz with aircraft ... I assume the optical link will not have = a dopper shift ?=20 And so into the night =20 73 -G., From: Markus Vester=20 Sent: Wednesday, October 24, 2012 11:53 PM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: OPERA OPTICAL BEACON (way off topic) but is based on 17 = KHz :) Hi Graham, similar...? WSPR decodes reliably at -29 dB, Op-2 requires -23 dB. Both = SNR figures are referenced to carrier power vs noise in 2.5 kHz. Op-8 = would be equivalent in sensitivity but takes four times as long, and = also conveys less data. In an optical subcarrier system, FSK will be no more difficult to = implement than ASK. And no average power is being saved by using 50% = duty cycle. Regarding the over the air comparison, please review the comment from = PA0A, pasted beneath. Sorry, but some statements just don't become more true by repeating them = again and again... =20 Best 73, Markus (DF6NM) From: Albert=20 Sent: Saturday, July 14, 2012 2:25 PM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: DUAL BEACON WSPR + OPERA 500Khz Graham, Regarding your dual mode 500 kHz tests yesterday. For me the absolute = winner is WSPR, when Opera stopped to decode, due to QSB, WSPR continued = with decodes at least 3 to 4 dB deeper into the noise.=20 73, Albert PA0A From: Graham=20 Sent: Thursday, October 25, 2012 12:24 AM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: OPERA OPTICAL BEACON (way off topic) but is based on 17 = KHz :) What's you measured error ? ..taking one is peak and one is = average and the beach mark is different as well, direct read-out = testing is not satisfactory. =20 Over a live radio path the statement is reasonably correct , op2 = may on the + side and op4 on the - side =20 I think the statement is technically correct, however , the = differences in the calibration and method do present a technical = quandary . Similar =3D having a resemblance in appearance, character, or = quantity, without being identical: In parallel transmission test over 25 miles on 500 k , the two = modes randomly decoded at and around the same level=20 However system implementation is the key , simplicity of use , with = minimal hardware requirements. as can be seen on the 136 band , = many stations are using the system with some very good results = , hopefully for field work with optical systems it will give a = reliable lap-top based SDR measuring system . =20 73 -G..=20 From: Markus Vester=20 Sent: Wednesday, October 24, 2012 10:48 PM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: OPERA OPTICAL BEACON (way off topic) but is based on 17 = KHz :) From: Graham=20 Sent: Wednesday, October 24, 2012 11:18 PM To: rsgb_lf_group@blacksheep.org=20 Subject: LF: OPERA OPTICAL BEACON (way off topic) but is based on 17 KHz = :) ... > and OP2 has similar sensitivity as the wspr system.=20 ... =20 this is definitely not true. 73, Markus ------=_NextPart_000_00BF_01CDB248.6F8F8AC0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Yes  I remember  those  tests  with  = Albert =20 , the  results where  totally  different to  the = local =20 25  mile  tests  with the  same  set up early = in=20 the  same  day . but that's  live  path  = testing =20 ...
 
fsk  , of  course , but  simplicity is  = the =20 object  , switching the (led)  light  off  = and  on=20 could   reduce the  duty  by  50%  = where =20 heat is  a problem , but that  is for  those who  = are=20 experimenting  in that  area ,    = adding  =20 a  17 KHz   band to the  modem  simply =20 allows  any one to  try , with the  minimal  = of =20 effort  , at the  moment the  only  path  = is =20 via  conventional   translation at  100% = carrier  ,=20 30  second  burst  should   work  on=20 satellite  scatter , works  fine  at 50MHz  = with =20 aircraft ...  I assume the  optical  link will  not =  =20 have  a  dopper  shift ?
 
And  so  into the  night 
 
73 -G.,
 
 
 
 

From: Markus Vester
Sent: Wednesday, October 24, 2012 11:53 PM
To: rsgb_lf_group@blacksheep.org= =20
Subject: Re: LF: OPERA OPTICAL BEACON (way off topic) but is = based=20 on 17 KHz :)

Hi Graham,
 
similar...? WSPR decodes reliably at = -29 dB,=20 Op-2 requires -23 dB. Both SNR figures are referenced=20 to carrier power vs noise in 2.5 kHz. Op-8 would be equivalent in=20 sensitivity but takes four times as long, and also conveys less=20 data.
 
In an optical = subcarrier=20 system, FSK will be no more difficult to implement than ASK. And no = average=20 power is being saved by using 50% duty cycle.
 
Regarding the over = the air=20 comparison, please review the comment from PA0A, pasted=20 beneath.
 
Sorry, but some=20 statements just don't become more true by repeating them again and=20 again... 
 
Best = 73,
Markus = (DF6NM)
 
 
From: Albert
Sent: Saturday, July 14, 2012 2:25 PM
To: rsgb_lf_group@blacksheep.org
Subject: Re: LF: DUAL BEACON WSPR + OPERA 500Khz

Graham,

Regarding your dual mode = 500 kHz=20 tests yesterday. For me the absolute winner is WSPR, when Opera stopped = to=20 decode, due to QSB, WSPR continued with decodes at least 3 to 4 dB = deeper into=20 the noise.

73, Albert PA0A

From: Graham
Sent: Thursday, October 25, 2012 12:24 AM
To: rsgb_lf_group@blacksheep.org= =20
Subject: Re: LF: OPERA OPTICAL BEACON (way off topic) but is = based=20 on 17 KHz :)

What's  you  measured  error  ? ..taking =20 one  is  peak  and one  is  average  = and =20 the  beach mark is  different  as well, =  direct =20 read-out testing  is not  satisfactory. 
 
Over a live  radio  path  the  statement  = is=20 reasonably  correct  , op2  may  on the  + = side =20 and  op4  on the  - side 
I think the  statement is  technically  correct, = however ,=20 the  differences in the  calibration  and  = method =20 do  present  a  technical quandary .
 
Similar   =3D   having = a=20 resemblance in appearance, character, or quantity, without being = identical:
 
In parallel  transmission test  = over =20 25  miles  on  500 k , the  two  modes =20 randomly  decoded at and  around the  same  level=20
 
However system implementation  is the = key =20 , simplicity  of use , with  minimal  hardware=20 requirements.  as can be  seen on the  136  band ,=20 many  stations  are  using  the  system = with =20 some  very  good  results , hopefully  = for =20 field   work  with  optical  systems  = it =20 will  give a reliable  lap-top based  SDR=20   measuring  system .  
 
73 -G..
 
 

From: Markus Vester
Sent: Wednesday, October 24, 2012 10:48 PM
To: rsgb_lf_group@blacksheep.org= =20
Subject: Re: LF: OPERA OPTICAL BEACON (way off topic) but is = based=20 on 17 KHz :)

From: Graham
Sent: Wednesday, October 24, 2012 11:18 PM
To: rsgb_lf_group@blacksheep.org= =20
Subject: LF: OPERA OPTICAL BEACON (way off topic) but is = based on 17=20 KHz :)

...

> and OP2 =20 has  similar  sensitivity as  the  wspr  system.

...

 

this is definitely not = true.
 
73, Markus
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