Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dd05.r1000.mx.aol.com (Internet Inbound) with ESMTP id 6E99C3800015A; Wed, 3 Aug 2011 16:04:08 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Qohf1-0001T9-Lv for rs_out_1@blacksheep.org; Wed, 03 Aug 2011 21:03:23 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Qohf1-0001T0-1m for rsgb_lf_group@blacksheep.org; Wed, 03 Aug 2011 21:03:23 +0100 Received: from relay.uni-heidelberg.de ([129.206.100.212]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Qohf0-0006if-60 for rsgb_lf_group@blacksheep.org; Wed, 03 Aug 2011 21:03:23 +0100 Received: from freitag.iup.uni-heidelberg.de (freitag.iup.uni-heidelberg.de [129.206.29.204]) by relay.uni-heidelberg.de (8.14.1/8.14.1) with ESMTP id p73K3KnU011654 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 3 Aug 2011 22:03:21 +0200 Received: from [129.206.22.206] (pc206.iup.uni-heidelberg.de [129.206.22.206]) by freitag.iup.uni-heidelberg.de (8.12.11.20060308/8.11.2) with ESMTP id p73K3LVM028572 for ; Wed, 3 Aug 2011 22:03:21 +0200 Message-ID: <4E39A8D2.2000800@iup.uni-heidelberg.de> Date: Wed, 03 Aug 2011 22:00:18 +0200 From: =?ISO-8859-1?Q?Stefan_Sch=E4fer?= User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: In-Reply-To: X-Spam-Score: 1.4 (+) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001,RATWARE_GECKO_BUILD=1.426 Subject: Re: LF: Antennas Content-Type: multipart/alternative; boundary="------------010003040309010400060204" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=HTML_MESSAGE 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-SCOLL-SCORE: 0:2:466109536:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d40914e39a9b77d06 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This is a multi-part message in MIME format. --------------010003040309010400060204 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Two things: If there is almost no activity on LF, why is then QRN/QRM a problem? Or would there really be more activity if QRN would be lower? I can hardly imagine we would have a full band or at least seeing 10% of the people who can transmit per week! And there is indded the possibility to do QSOs, even in summer. I've worked G3XIZ 3 times during the summer months. It does not work any time but it is the same on HF. UK stations could work each other. There are plenty of possible active stations. But i almost never see a QSO on the G4WGT grabber. BTW i'm just working DL6MDD for the first time. :-) Another thing: We could all work on a common project and try to set up an easy to use FM link for a small remote located converter, perhaps running on solar power or maybe batteries. This could be an interesting alternative for many of us, me too of course. There could be a big improvement by placing the RX 100m apart from the house. As long as you don't live in the center of a city, the improvement could be above 10 dB. Ah, still a 3rd thing that has to do with the 2nd: Why are there not much more /p activities? It's so easy and nice to be outside, like in the early morning which is good for groundwave QSOs. We could arrange a small /p fieldday, an activity day instead of mourning about the good old times. Let's go! :-) 73, Stefan/DK7FC PS: Just finished an outlet of my 70cm TX that is H when the squelch is opened. Now feeding that to a BS170 that will drive a CNY17-4 optocoupler that will drive the PTT! So this allows me to key my PA from some km distant transmitting on 43x.xxx MHz ;-) This is how we could be QRV from /p, just with a RX antenna, having the TX at home! Am 03.08.2011 21:01, schrieb Roger Lapthorn: > Mal > > You may be right about big antennas in a decent, quiet rural location > but the majority of us now live close to modern civilisation with > noise floors that have risen some 20-30dB or more at the lower end of > the spectrum in recent years. > > Top Band is almost unusable here and 80m not a lot better. I am > surprisingly lucky on 500kHz and 136kHz where I seem to be able to > hold my own on receive with my loop antenna in its favoured > directions. Many get very good results with PA0RDT type E-field probe > antennas with careful location and after efforts to minimise noise > pick-up. In the end S/N is all that matters so having a large antenna > which increases both wanted signal /and/ noise has no benefit as long > as the S/N is as good as it can be. > > With more and more difficult noise environments in most urban and > semi-urban locations I can see many people giving up amateur radio > below 432MHz. I am tempted more and more to move up to the UHF and > microwave region to get my next challenges and I live on the edge of a > village where the noise must be far less of an issue than for my city > friends. > > A little more understanding of the plight of many LFers in busy cities > and some /encouraging/ words and ideas would be good Mal. > > 73s > Roger G3XBM > > > > On 3 August 2011 19:08, Chris > wrote: > > Hi Mal and LF, > Well, all I can say is that here the signal to noise ratio on RX > is better on my PA0RDT than it is on my long wire (inverted 'L'). > I have always thought this a bit strange, quite often weak signals > that cannot be seen on the wire are perfectly copied on the > PA0RDT. This applies from 136kHz to 3.8MHz. I cannot see what else > it can be other than local noise/QRM level. 80m is another prime > example where the noise has gradually got worse over the years here. > Vy 73, > Chris, G4AYT, Whitstable, Kent. > > > > > -- > http://g3xbm-qrp.blogspot.com/ > http://www.g3xbm.co.uk > http://www.youtube.com/user/g3xbm > https://sites.google.com/site/sub9khz/ > --------------010003040309010400060204 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Two things:

If there is almost no activity on LF, why is then QRN/QRM a problem? Or would there really be more activity if QRN would be lower? I can hardly imagine we would have a full band or at least seeing 10% of the people who can transmit per week!
And there is indded the possibility to do QSOs, even in summer. I've worked G3XIZ 3 times during the summer months. It does not work any time but it is the same on HF.
UK stations could work each other. There are plenty of possible active stations. But i almost never see a QSO on the G4WGT grabber. BTW i'm just working DL6MDD for the first time. :-)

Another thing: We could all work on a common project and try to set up an easy to use FM link for a small remote located converter, perhaps running on solar power or maybe batteries. This could be an interesting alternative for many of us, me too of course. There could be a big improvement by placing the RX 100m apart from the house. As long as you don't live in the center of a city, the improvement could be above 10 dB.

Ah, still a 3rd thing that has to do with the 2nd:
Why are there not much more /p activities? It's so easy and nice to be outside, like in the early morning which is good for groundwave QSOs.

We could arrange a small /p fieldday, an activity day instead of mourning about the good old times.

Let's go! :-)

73, Stefan/DK7FC

PS: Just finished an outlet of my 70cm TX that is H when the squelch is opened. Now feeding that to a BS170 that will drive a CNY17-4 optocoupler that will drive the PTT! So this allows me to key my PA from some km distant transmitting on 43x.xxx MHz ;-) This is how we could be QRV from /p, just with a RX antenna, having the TX at home!




Am 03.08.2011 21:01, schrieb Roger Lapthorn:
Mal

You may be right about big antennas in a decent, quiet rural location but the majority of us now live close to modern civilisation with noise floors that have risen some 20-30dB or more at the lower end of the spectrum in recent years.

Top Band is almost unusable here and 80m not a lot better. I am surprisingly lucky on 500kHz and 136kHz where I seem to be able to hold my own on receive with my loop antenna in its favoured directions. Many get very good results with PA0RDT type E-field probe antennas with careful location and after efforts to minimise noise pick-up. In the end S/N is all that matters so having a large antenna which increases both wanted signal and noise has no benefit as long as the S/N is as good as it can be.

With more and more difficult noise environments in most urban and semi-urban locations I can see many people giving up amateur radio below 432MHz.  I am tempted more and more to move up to the UHF and microwave region to get my next challenges and I live on the edge of a village where the noise must be far less of an issue than for my city friends.

A little more understanding of the plight of many LFers in busy cities and some encouraging words and ideas would be good Mal.

73s
Roger G3XBM



On 3 August 2011 19:08, Chris <c.ashby435@btinternet.com> wrote:
Hi Mal and LF,
Well, all I can say is that here the signal to noise ratio on RX is better on my PA0RDT than it is on my long wire (inverted 'L'). I have always thought this a bit strange, quite often weak signals that cannot be seen on the wire are perfectly copied on the PA0RDT. This applies from 136kHz to 3.8MHz. I cannot see what else it can be other than local noise/QRM level. 80m is another prime example where the noise has gradually got worse over the years here.
Vy 73,
Chris, G4AYT, Whitstable, Kent.



--
http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www.youtube.com/user/g3xbm
https://sites.google.com/site/sub9khz/

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