Return to KLUBNL.PL main page

rsgb_lf_group
[Top] [All Lists]

Re: LF: 4X OP32 report

To: <[email protected]>
Subject: Re: LF: 4X OP32 report
From: "Graham" <[email protected]>
Date: Wed, 25 Jul 2012 17:07:44 +0100
Importance: Normal
In-reply-to: <[email protected]>
References: <CAK59VFNOneVPmCEjVc1kK3FpvfmCX5qp_gZo5-AFy58Hmiq-6g@mail.gmail.com> <[email protected]> <DEF0879101734958AE61D0D590E070DF@AGB> <[email protected]>
Reply-to: [email protected]
Sender: [email protected]

schrieb   Stefan, :)

Why do you think so?

Its linked to the DSP engine in Op , there is a timing issue , if other applications lock the sound card at a different rate , due to the % tolerances , low level decodes can be lost , noting, Op is a 'data mode , so the overheads in the transmission are much higher , as are the DSP engine requirements , as can be seen with 'older' pc's cpu loading can be a issue , as is a one-pass system , all the processing is taking place in real time

But  on with the  show ,

73 -G..

-76 dB in 28 mHz b/w , what is that when translated to 2.5Khz B/w ?




--------------------------------------------------
From: "Stefan Schäfer" <[email protected]>
Sent: Wednesday, July 25, 2012 3:08 PM
To: <[email protected]>
Subject: Re: LF: 4X OP32 report


Am 25.07.2012 15:51, schrieb Graham:

Pity nothing decoded in the US last night , but signal 's in 1500 /2000 mile range where quite substantial ... from this , it seems that propagation on 136 is really linked to the seasons ?

Yes (of course) and no. W1VD received me quite well a few weeks ago, see https://dl.dropbox.com/u/19882028/LF/07_July2012.jpg Not to forget W1TAG: https://dl.dropbox.com/u/19882028/LF/DK7FC_Juli2012.jpg

So there is some propagation in summer but of course it depends on the solar activity. Don't know how the condx have been yesterday.

One point from previous trials , If Spec-lab is used with Opera , then SL must be set to 48Khz sample rate , or OP can loose low level decode sensitivity.
Why do you think so? As long as the frequency range of a SSB bandwidth at audio levels passes through the SL filter, then it should be fine. So 8 kHz SR should be fine. Of course it depends on which shift frequency you have to use. I have to use 11 kHz shift and so i choosed a SR of 30 kHz.


73, Stefan



<Prev in Thread] Current Thread [Next in Thread>