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Message-ID: <3.0.1.16.20020329114803.3c979876@pb623250.kuleuven.be>
Date: Fri, 29 Mar 2002 11:48:03
To: rsgb_lf_group@blacksheep.org
From: "Rik Strobbe" <rik.strobbe@fys.kuleuven.ac.be>
Subject: Re: LF: 1-st RUS LF DX-pedition #2
In-reply-to: <19519.020329@dx.ru>
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Hello Ed,

receiving DCF39 with 9+40dB is a very good sign. But as you mention the
large antenna will pick up a lot of strong signals causing intermodulation
in teh RX. Although bringing the antenna to resonance (by the loading coil)
will attenuate the out-of-band signals (but probably not DCF39) it will be
usefull to have an attenuator between the antenna and RX. At home, where I
use a 14m high and 22m long inv-L, I have found out that 20dB attenuation
give the best result. So with the big antenna you might need up to 40dB (a
step attenuator migh be best) , without any attenuattion you will probably
just hear a 'boiling pot'.

Good luck with the 136kHz tests, looking foward to work you in QRSS or DFCW.

73, Rik  ON7YD

At 12:27 29/03/02 +0300, you wrote:
>Hello rsgb_lf_group!
>
>Last news (8z 29 mar):
>
>- March, 28 at last have got the sanction to work to a tower and in 17z the
>LF ANT already was groundless
>
>- ANT should be simplified :
>               110m long
>                |
>                V       |
>    h=~90m->----------- |<- h=131m
>             \          |
>               \        |
>    150m long-> \       |
>                   \    |
>                     \  |
>                   TX O |
>Wires of the ANT - Litz-wire 175x0.1 (~2mm - ekw Cu diam ~1.5mm)abt 280m
>long over 5mm Polypropilene cord 470m long
>
>- DFC39 it became audible on S 59+40 without any coil, filters, amplifiers
>and ATT.
>The voltage on the end (without coil)of ANT below has made ~4V
>Cross-modulation is very strong.
>
>-  Now  we  make  updating  Band-pass  and coil (diam ~40cm, Litz-wire
>   175x0.1mm abt 700-1000 mkH
>
>- Have strengthened team Serge UA6LFQ - Let's try to organize round-the-clock
>  work
>
>- If know Russian and there is a Russian coding in Windows can inform me on a
>pager on http://crypt.rnd.ru for 29600 (rus or engl)
>  or via e-mail: vesso@crypt.rnd.ru  Subject: 29600  In body: text
>  Pager will be used in time DX-pedition
>
>- First QSO will be RU6LWZ - call our club
>
>73! Ed RU6LA          mailto:ed@dx.ru
>
>
>
>