Message-ID: <BCB3DD0B3A484B3D914934ED89AF3604@AGB>
From: "Graham" <g8fzk@g8fzk.fsnet.co.uk>
To: <rsgb_lf_group@blacksheep.org>
References: <C3F731D3B3D442FDBAA8720F953F74A5@AGB> <F09855DF575643A69705E0C805514AC1@2a2d7ed321c6425> <E0F8753816EF48A5A08EA8B704F787EA@AGB> <4FFA2783.9080906@kpnmail.nl> <CC76ACE4114B46C287B68D45D8B20D19@AGB> <1341854812.85253.YahooMailNeo@web171604.mail.ir2.yahoo.com> <A590C5270A984DEFB1E0CDB5FA76DC51@AGB> <1341915060.76392.YahooMailNeo@web171605.mail.ir2.yahoo.com> <1341923384.41558.YahooMailNeo@web171602.mail.ir2.yahoo.com> <4FFC2C4E.5090306@iup.uni-heidelberg.de> <4FFC3518.1030405@xs4all.nl>
In-Reply-To: <4FFC3518.1030405@xs4all.nl>
Date: Tue, 10 Jul 2012 16:56:59 +0100
MIME-Version: 1.0
Importance: Normal
Subject: Re: LF:  OPERA  Question
Content-Type: text/plain;
	format=flowed;
	charset="iso-8859-1";
	reply-type=response
Content-Transfer-Encoding: 7bit
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org
X-AOL-SCOLL-URL_COUNT: 0  
x-aol-sid: 3039ac1d60154ffc510e7014
X-AOL-IP: 195.171.43.25
X-AOL-SPF: domain : blacksheep.org SPF : none


Yes  , with  one correction  , ( for   audio  drive)

The  carrier placement   routine, when  Tx is  selected  , scans  the Rx 
audio  band and selects  the  lowest s/n  spot  frequency in that  range

So  if you  are  using  a  transverter   (or on frequency  exciter  )  then 
the TX frequency  is  decided by the  audio  drive  frequency  inside the 
limits  (red-lines)   for  that  mode/speed

If  using  manual  frequency selection, then  a Tx  frequency  must  be 
selected, that  will  produce a  carrier/hetrodyne  that  falls  inside the 
audio pass  band  (red-lines)  defined  by convention as  'dial  set  usb 
frequency'

Changing  the  speed  also  requires a  change  of  frequency  to  place the 
carrier  inside the  correct  filter , automated  if  using  audio-drive.

Narrow   IF filters  are  not  desirable  and   reduce the  performance of 
the  demodulator  , better  simply  use  SSB  filter

NB :  The  pass  band  edges  are  quite  sharp  , so  ensure  you  are 
'inside' and  not  'on the  line'  or  you  may  fail  to  decode  ....... 
also   tx / rx   frequency  alignment   may  place you  out  side ....  i

Keying  , recommended  that  the  TX be  held in 'tx'   , to  prevent  tx/rx 
change over  times  from  altering  the  keying  times .... not  100%  a 
problem , but  to  enable  decodes the  lower levels  , time +/-  and 
frequency  +/-  need  to  be as  close to the  generated values   as 
possible


GL ..73 -G..


--------------------------------------------------
From: "Albert" <westberg@xs4all.nl>
Sent: Tuesday, July 10, 2012 2:58 PM
To: <rsgb_lf_group@blacksheep.org>
Subject: Re: LF:  OPERA  Question

> Stefan,
>
> Download the Opera program. In the waterfall you will see two red lines, 
> put the cursor on the lines and read the frequency (upper left window of 
> the waterfall display)  Op4 differs from Op8 etc a frequency within this 
> band is the input of the USB TX so 477kHz + (a frequency between the red 
> lines). When using CAT control Opera will choose a not occupied freq. in 
> the appropriate pass band.
>
> 73, Albert
>
>