Return-Path: Received: from mtain-mb05.r1000.mx.aol.com (mtain-mb05.r1000.mx.aol.com [172.29.96.25]) by air-da10.mail.aol.com (v129.4) with ESMTP id MAILINDA104-86944c1fab49286; Mon, 21 Jun 2010 14:11:21 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-mb05.r1000.mx.aol.com (Internet Inbound) with ESMTP id 5604138000111; Mon, 21 Jun 2010 14:11:19 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1OQlS6-00070T-DK for rs_out_1@blacksheep.org; Mon, 21 Jun 2010 19:10:34 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1OQlS5-00070K-NY for rsgb_lf_group@blacksheep.org; Mon, 21 Jun 2010 19:10:33 +0100 Received: from p3plsmtpa01-01.prod.phx3.secureserver.net ([72.167.82.81]) by relay1.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1OQlS1-0002Ru-Je for rsgb_lf_group@blacksheep.org; Mon, 21 Jun 2010 19:10:33 +0100 Received: (qmail 14442 invoked from network); 21 Jun 2010 17:43:42 -0000 Received: from unknown (188.4.104.45) by p3plsmtpa01-01.prod.phx3.secureserver.net (72.167.82.81) with ESMTP; 21 Jun 2010 17:42:56 -0000 Received: from 127.0.0.1 (AVG SMTP 9.0.829 [271.1.1/2953]); Mon, 21 Jun 2010 20:43:07 +0300 Message-ID: <000e01cb1169$355544d0$0101a8c0@amd4800> From: "George Vastianos" To: References: Date: Mon, 21 Jun 2010 20:43:07 +0300 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: LF: Re: Earth mode DXing today - 3.6kms! Content-Type: multipart/mixed; boundary="=======AVGMAIL-6A361377=======" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.1 required=5.0 tests=HTML_MESSAGE,LINES_OF_YELLING, LINES_OF_YELLING_2 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-sid: 3039ac1d60194c1fab47133e X-AOL-IP: 193.82.116.20 --=======AVGMAIL-6A361377======= Content-Type: multipart/alternative; boundary="----=_NextPart_000_000B_01CB1182.5A694460" ------=_NextPart_000_000B_01CB1182.5A694460 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: quoted-printable CONGRATULATIONS!!!!!!!!!!!!!!!!! FROM 0.01KM ON EARTH MODE SOME MONTHS AGO NOW YOU WENT ON 3.6KM!!! 73 SV8GXC ----- Original Message -----=20 From: Roger Lapthorn=20 To: rsgb_lf_group@blacksheep.org=20 Cc: M0BXT=20 Sent: Monday, June 21, 2010 7:55 PM Subject: LF: Earth mode DXing today - 3.6kms! MODS TO THE SYSTEM Some significant steps taken with my local earth mode / induction te= sts today, which I'll summarise here. Spectran screen captures will ap= pear on my earth mode web page tomorrow.=20 a.. Firstly, having installed the K1EL keyer chip, I decided to us= e its internal 800Hz sidetone oscillator, after a bit of LP filtering,= to drive my 4W PA. This arrangement now allows me to run either QRSS3= or 10wpm CW beacons on 800Hz at the flick of a switch. It is more sta= ble than the external twin-tee oscillator I was using and is perfectly= suitable for QRSS3 at audio frequencies. b.. Secondly, I modified my loop/preamp to have marginally better= sensitivity at around 700-900Hz. c.. A quick "by ear" test with the switch in the 10wpm position an= d the 0.5km range I'd managed before was achieved using the 80cm loop= and the 20m baseline earth electrodes. QRSS3 DX Now here comes the real fun. At this point I decided to take my loop= , preamp and laptop equipped with Spectran out into the field to see= what I could see/hear. a.. My first location was a field 0.75km south of the QTH just out= of the village. Although nothing could be heard, the QRSS trace was= solid on the screen. b.. Next step was to proceed further south along the Heath Road ou= t of Burwell (QTH JO02dg) to a point 2.5km away from the QTH. Again,= with Spectran, a good signal was visible on the screen. At one point= when rotating the loop I could hear the signal too. c.. The next test was to go out of the village on a different road= (towards Cambridge) to a car park adjacent to the Devils Dyke. This= was 1.4km away from the TX but about 40 degrees further to the west= than the earlier test locations. Immediately the loop was set up (lea= ning against the back of the car) a good clear signal was visible, aga= in no audible signal though.=20 d.. At this point I decided to "go for broke" and drove down anoth= er rural lane to a roadside spot 3.6km away from home, but in the dire= ction of fire of the TX earth electrode loop. Setting up beside the co= untry lane I could see the QRSS signal on the screen!! Best orientatio= n was with the loop orthogonal to the village, which by now was too fa= r away to see over the slightly rising ground.=20 At this point my laptop batteries were dying and I had to get some= food for my wife for tea, so I packed up and came home, very happy. CONCLUSIONS a.. Going from 10wpm CW to QRSS3 has made an amazing difference:= signals that cannot be heard are visible, and at decent distances. Th= is is a new experience for me, but not others here. b.. The free running sidetone oscillator in the K1EL keyer is fine= for QRSS3, certainly for tests of about 1-2 hours long. c.. I suspect some "utility coupling" is going on, although at the= furtherest point loop orientation did line up with the village. Is th= e signal propagating along the water pipes to some extent? d.. With "utility coupling" I suspect that getting a report from= G6ALB in the next village will already be possible on VLF as I've alr= eady heard my signal at a greater distance than he is from me.=20 e.. At VLF, I am wondering just how far is possible in semi-rural= areas with manageable 50Hz noise levels (it is well filtered in my RX= ) and with some degree of "utility coupling" which is inevitable in to= day's world where pipes and wires criss-cross everywhere.=20 f.. Even with just 4W and QRSS, remarkable distances can be achiev= ed. Clearly I could get further than 3.6km already with the same equip= ment at each end. NEXT STEPS a.. I need a location right out in the wilds (a bit hard to find= in SE England) for further tests, to see what performance is like wit= hout any coupling into water pipes etc..=20 b.. Add the screen shots and audio clips to the sub-9kHz webpage. c.. Increase the area of the TX loop part that is in the air as th= is could add another 3dB to signal level.=20 d.. More power? Loops at both ends? ....? 73s Roger G3XBM --=20 http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk http://www.youtube.com/user/g3xbm G3XBM GQRP 1678 ISWL G11088 ----------------------------------------------------------------------= -------- No virus found in this incoming message. Checked by AVG - www.avg.com=20 Version: 9.0.829 / Virus Database: 271.1.1/2953 - Release Date: 06/2= 1/10 09:36:00 ------=_NextPart_000_000B_01CB1182.5A694460 Content-Type: text/html; charset="ISO-8859-1" Content-Transfer-Encoding: quoted-printable
CONGRATULATIONS!!!!!!!!!!!!!!!!!
 
FROM 0.01KM ON EARTH MODE SOME MONTHS= AGO NOW YOU=20 WENT ON 3.6KM!!!
 
73
SV8GXC
----- Original Message -----
Cc: M0BXT
Sent: Monday, June 21, 2010= 7:55 PM
Subject: LF: Earth mode DXing= today -=20 3.6kms!

MODS TO THE SYSTEM

Some significant<= /U> steps=20 taken with my local earth mode / induction tests today, which I'll= summarise=20 here. Spectran screen captures will appear on my earth mode web=20 page tomorrow.
  • Firstly, having installed the K1EL keyer chip, I decided to us= e its=20 internal 800Hz sidetone oscillator, after a bit of LP filtering,= to drive my=20 4W PA. This arrangement now allows me to run either QRSS3 or 10wpm= CW=20 beacons on 800Hz at the flick of a switch. It is more stable than= the=20 external twin-tee oscillator I was using and is perfectly suitable= for QRSS3=20 at audio frequencies.
  • Secondly, I modified my loop/preamp to have marginally better= =20 sensitivity at around 700-900Hz.
  • A quick "by ear" test with the switch in the 10wpm position an= d the=20 0.5km range I'd managed before was achieved using the 80cm loop an= d the 20m=20 baseline earth electrodes.
QRSS3 DX

Now= here comes=20 the real fun. At this point I decided to take my loop, preamp= and=20 laptop equipped with Spectran out into the field to see what I could= see/hear.
  • My first location was a field 0.75km south of the QTH= just out of=20 the village. Although nothing could be heard, the QRSS trace was= solid on=20 the screen.
  • Next step was to proceed further south along the Heath Road ou= t of=20 Burwell (QTH JO02dg) to a point 2.5km away from the QTH. Ag= ain, with=20 Spectran, a good signal was visible on the screen. At one point wh= en=20 rotating the loop I could hear the signal too.
  • The next test was to go out of the village on a different road= (towards=20 Cambridge) to a car park adjacent to the Devils Dyke. This was = 1.4km=20 away from the TX but about 40 degrees further to the west than the= earlier=20 test locations. Immediately the loop was set up (leaning against= the back of=20 the car) a good clear signal was visible, again no audible signal= though.=20
  • At this point I decided to "go for broke" and drove down anoth= er rural=20 lane to a roadside spot 3.6km away from home, but in the di= rection of=20 fire of the TX earth electrode loop. Setting up beside the country= lane I=20 could see the QRSS signal on the screen!! Best orientation was wit= h the loop=20 orthogonal to the village, which by now was too far away to see ov= er the=20 slightly rising ground.
At this point my laptop batterie= s were dying=20 and I had to get some food for my wife for tea, so I packed up and= came home,=20 very happy.

CONCLUSIONS
  • Going from 10wpm CW to QRSS3 has made an amazing difference:= signals=20 that cannot be heard are visible, and at decent distances. This is= a new=20 experience for me, but not others here.
  • The free running sidetone oscillator in the K1EL keyer is fine= for=20 QRSS3, certainly for tests of about 1-2 hours long.
  • I suspect some "utility coupling" is going on, although at the= =20 furtherest point loop orientation did line up with the village. Is= the=20 signal propagating along the water pipes to some extent?
  • With "utility coupling" I suspect that getting a report from= G6ALB in=20 the next village will already be possible on VLF as I've already= heard my=20 signal at a greater distance than he is from me.=20
  • At VLF, I am wondering just how far is possible in semi-rural= areas with=20 manageable 50Hz noise levels (it is well filtered in my RX) and wi= th some=20 degree of "utility coupling" which is inevitable in today's world= where=20 pipes and wires criss-cross everywhere.=20
  • Even with just 4W and QRSS, remarkable distances can be achiev= ed.=20 Clearly I could get further than 3.6km already with the same equip= ment at=20 each end.
NEXT STEPS
  • I need a location right out in the wilds (a bit hard to find= in SE=20 England) for further tests, to see what performance is like withou= t any=20 coupling into water pipes etc..
  • Add the screen shots and audio clips to the sub-9kHz=20 webpage.
  • Increase the area of the TX loop part that is in the air as th= is could=20 add another 3dB to signal level.=20
  • More power? Loops at both ends? ....?
73s<= BR>Roger=20 G3XBM
--
http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http= ://www.youtube.com/user/g3xbm
G3XBM    GQRP=20 1678      ISWL G11088


No virus found in this incoming message.
Checked by AV= G -=20 www.avg.com
Version: 9.0.829 / Virus Database: 271.1.1/2953 - Re= lease=20 Date: 06/21/10 09:36:00
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