Envelope-to: dave@picks.force9.co.uk
Delivery-date: Tue, 31 Jan 2006 14:44:12 +0000
Date: Tue, 31 Jan 2006 15:41:44 +0100
From: Hartmut Wolff <wolff.h@t-online.de>
Message-ID: <1465562953.20060131154144@t-online.de>
To: dj9dw <rsgb_lf_group@blacksheep.org>
In-Reply-To: <000b01c62672$59053ac0$ee9bfea9@oben>
References: <003301c6263d$8c89cee0$0100a8c0@jpmpcportable>
 <002101c6264f$35250bd0$2201a8c0@pcroelof> <000b01c62672$59053ac0$ee9bfea9@oben>
MIME-Version: 1.0
Subject: LF: Re: Bandwidth - was T/A JAN 31
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 8bit
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org

Hi Peter, Roelof and group,

during last summer I made a side by side test with 2 JRC NRD525 rx.
One with 125Hz Inrad IF-filter and the other with the original JRC 300Hz
IF-filter. At that time the band was very noisy due to T-storms. I saw
nearly no difference on a QRSS3 screen, but on every slower screen the
narrower Bandwidth performed much poorer. On the screens was much more
noise visible. With the same filter both rx performed equal. No
problems with the databursts of the DCF39 90km away from here with the
wider 300Hz filter.

73
Hartmut


> Hi Roelof and group,
> in my location - JO40LE - close to Mainflingen -DCF - I had to increase BW
> for better rx-performence. The noise was caused by databursts from that
> nearby commercial LF-TX. Narrow band and "good" shape-factor in the
> IF-Filters meant tendency to ring. We are in the time-domain with it.
> IF-filters with Gaussconfiguration prooved to be much more useful in this my
> case.
> Facit: the more steady the noise, the more narrow the BW can be choosen.
> But yet, never seen any TA so far. We work on it.
> Best regards,
> Peter, dj9dw

> ----- Original Message ----- 
> From: "Roelof Bakker" <roelof@ndb.demon.nl>
> To: <rsgb_lf_group@blacksheep.org>
> Sent: Tuesday, January 31, 2006 11:15 AM
> Subject: LF: T/A JAN 31


>> Hello all,
>>
>> Last night I tried ARGO.
>> The band started very noisy, but I got captures of WD2XKO and WD2XGJ.
>> VO1NA appeared later.
>>
>> I have heard rumours that ARGO and SpecLab need some background noise to
>> compare the signals against and hence should work better with a (relative)
>> wider bandwidth.
>> At present, I am using a 12 Hz bandwidth and both programs seem to work
>> fine.
>> Can anyone shed some light on this?
>>
>> Thank you in advance,
>>
>> Roelof Bakker, pa0rdt
>>