Return-Path: Received: from mtain-mh12.r1000.mx.aol.com (mtain-mh12.r1000.mx.aol.com [172.29.96.224]) by air-md08.mail.aol.com (v127_r1.1) with ESMTP id MAILINMD083-8b924b8a66cd1e3; Sun, 28 Feb 2010 07:51:25 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-mh12.r1000.mx.aol.com (Internet Inbound) with ESMTP id 4DF203800009A; Sun, 28 Feb 2010 07:51:23 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NliaR-0004Dq-Ue for rs_out_1@blacksheep.org; Sun, 28 Feb 2010 12:49:31 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NliaQ-0004Dh-OY for rsgb_lf_group@blacksheep.org; Sun, 28 Feb 2010 12:49:30 +0000 Received: from imr-da06.mx.aol.com ([205.188.169.203]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NliaO-0007Tj-5G for rsgb_lf_group@blacksheep.org; Sun, 28 Feb 2010 12:49:30 +0000 Received: from mtaout-db01.r1000.mx.aol.com (mtaout-db01.r1000.mx.aol.com [172.29.51.193]) by imr-da06.mx.aol.com (8.14.1/8.14.1) with ESMTP id o1SCnFB8011144 for ; Sun, 28 Feb 2010 07:49:15 -0500 Received: from Black (e179166161.adsl.alicedsl.de [85.179.166.161]) by mtaout-db01.r1000.mx.aol.com (WebSuites/MUA Thirdparty client Interface) with ESMTPA id 3CD74E0000A9 for ; Sun, 28 Feb 2010 07:49:14 -0500 (EST) Message-ID: <8F98AB84B99B4DC1BBD55E264D6FC983@Black> From: "Markus Vester" To: References: <38A51B74B884D74083D7950AD0DD85E82A1B21@File-Server-HST.hst.e-technik.tu-darmstadt.de> In-Reply-To: <38A51B74B884D74083D7950AD0DD85E82A1B21@File-Server-HST.hst.e-technik.tu-darmstadt.de> Date: Sun, 28 Feb 2010 13:48:59 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6000.16480 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6000.16669 x-aol-global-disposition: G x-aol-sid: 3039ac1d33c14b8a664a61c6 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: LF: Re: VLF TX experiments this sunday Content-Type: multipart/alternative; boundary="----=_NextPart_000_0006_01CAB87C.C745DB20" 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, MISSING_OUTLOOK_NAME 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: 3039ac1d60e04b8a66cb5b55 X-AOL-IP: 193.82.116.20 ------=_NextPart_000_0006_01CAB87C.C745DB20 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Dear LF, Stefan DK7FC just called me on the phone. He asked me to inform the gr= oup that because of much heavier winds than expected, he will not be= able to transmit from the kite antenna today. He also mentioned that= the output matching of his PA (a converted SMPS circuit) will require= some more work. Kind regards, Markus (DF6NM) ----- Original Message -----=20 From: Stefan Sch=E4fer=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Saturday, February 27, 2010 3:33 PM Subject: LF: VLF TX experiments this sunday becomes more probably Dear LF group,=20 =20 Tomorrow, the wind forecast is excellent! See http://www.windfinder.= com/forecast/frankfurt It is almost to much wind but i have the new kite braid with a stren= ght of 500kg... So the antenna will be in a high angle and stable for= tests. That is the first positive news. =20 Yesterday i got such a air coil. It has not 85mH but even about 100m= H but It's Q is bad at 8,9kHz, just about 38. Anyway, i will easily ha= ndle 20kV rms. This will be the maximum voltage on my single wire. The= re are several possibilities to increase the maximum antenna voltage,= well known and applied in the high voltage power fields but this may= be very difficult at a kite antenna. So i will start with a first tes= t at only 20kV, if the PA will give a proper power ;-) =20 That coil is very heavy, about 50kg, really no fun to carry that and= there are better ways to realisethat. But it is available i get the= chance to resonate that 100m vertical at 8,9kHz. I tried to resonate= it in the living room of my parents since it it to heavy to carry it= in my room in the first floor ;-) It was successfully resonated with= 6x22nF/6kV plus a lower voltage C in series, about 33nF/2kV and a DDS= VFO with a sinus output, loosely coupled by another air coil (in this= way i will be able to make a transformation of the resonated loop!(va= rying the coupling)). The 8,9kHz are well audible so i am excited how= the antenna and coil will sound when some 100W applied;-) =20 The last problem is the PA since it is not yet available. I will try= to built it today or tomorrow in the morning but i have also to spend= some time with my YL. I hope that can be arranged... =20 On the hill i have no internet but i will at least inform Markus/DF6= NM to give those who are interested a information here... =20 I have to go now, and will inform you... =20 73, Stefan/DK7FC ________________________________ Von: owner-rsgb_lf_group@blacksheep.org im Auftrag von Alexander S.= Yurkov Gesendet: Sa 27.02.2010 20:37 An: rsgb_lf_group@blacksheep.org Betreff: RE: LF: Fwd: Special Permits for Amateur Radio Operation be= low 9kHz? > when back in the mid 90's the initial request for a longwave amate= ur > segment (what later turned out to be 137kHz) was discussed, one of= the > big telecom "bobo's" stated that they saw no harm that amateurs wo= uld > transmit there with max. 1 W EIRP as with that power one wouldn't= be > able to get any further than the other end of the town. > It turned out a bit different, unless you see the world as one big= town ;-) Rik, after some theoretical estimations done i am absolutely shure= =20 QRSS communications at few 100s km (may be more) is posible on 9 kHz= . There is lot of problems on TX side but them to be solvable. Main pr= oblem is high voltage on the TX ANT. I expect 100 - 200 kV is reachable wi= th some 'tricks' wellknown for power ingeneers. For example one should= avoid free end of a wire with such a voltage. On should use 'protecting ri= ngs' on the ends. With voltage abt 100 kV seems to be posible use not too= high antenna. Seems 20-30 m high well top loaded marconi designed special= ly for high voltage is adequate. Remember effective height of 60m kite ante= nna used in DK8KW experiment was 30m (if wire was absolutelly vertical,= does it was?). With not too high voltage and not too large ANT capacity= 4.5 km was reached. Another key problem is noise level on this freq. Now we= see huge discrepancy on the noise level got from different sourses. What= is the real noise level is not obvious now. Can it be much lower time= to time? Experements to be usefull. Look at DK8KW web side where 4.5 km experiment is described. Waterfall background is too smooth. Where spherics are? This is why i expect RX sensetivity was not as high as posible. One should remember 4.5 km is begining of the wave= zone on 9 kHz. At distanses more then 4.5 km field decreases not too fast= with distance. Another critical distance is abt 100 km where 'waveguide' propagation starts. At such distances one shold increase TX ANT volt= age only in 3 times to reach distance 10 times more. Anyway Stefan's experiment will be very intesesting. And i hope it will be not the= last experiment. Regards, Alexander/RA9MB ------=_NextPart_000_0006_01CAB87C.C745DB20 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Dear LF,
 
Stefan DK7FC just called me on the ph= one. He asked=20 me to inform the group that because of much heavier winds than expecte= d, he will=20 not be able to transmit from the kite antenna today. He also= mentioned=20 that the output matching of his PA (a converted SMPS circuit= ) will=20 require some more work.
 
Kind regards,
Markus (DF6NM)
 
----- Original Message -----
Sent: Saturday, February 27,= 2010 3:33=20 PM
Subject: LF: VLF TX experimen= ts this=20 sunday becomes more probably

Dear LF group,
 
Tomorrow, the wind forec= ast is=20 excellent! See http://www.windfinder.com/forecast/frankfurt
It=20 is almost to much wind but i have the new kite braid with a strenght= of=20 500kg... So the antenna will be in a high angle and stable for tests= . That is=20 the first positive news.
 
Yesterday i got such a air coi= l. It has=20 not 85mH but even about 100mH but It's Q is bad at 8,9kHz, just abou= t 38.=20 Anyway, i will easily handle 20kV rms. This will be the maximum volt= age on my=20 single wire. There are several possibilities to increase the maximum= antenna=20 voltage, well known and applied in the high voltage power fields but= this may=20 be very difficult at a kite antenna. So i will start with a first te= st at only=20 20kV, if the PA will give a proper power ;-)
 
That coil= is very=20 heavy, about 50kg, really no fun to carry that and there are better= ways to=20 realisethat. But it is available i get the chance to resonate that= 100m=20 vertical at 8,9kHz. I tried to resonate it in the living room of my= parents=20 since it it to heavy to carry it in my room in the first floor ;-)= It was=20 successfully resonated with 6x22nF/6kV plus a lower voltage C in ser= ies, about=20 33nF/2kV and a DDS VFO with a sinus output, loosely coupled by anoth= er air=20 coil (in this way i will be able to make a transformation of the res= onated=20 loop!(varying the coupling)). The 8,9kHz are well audible so i am ex= cited how=20 the antenna and coil will sound when some 100W applied;-)
 <= BR>The=20 last problem is the PA since it is not yet available. I will try to= built it=20 today or tomorrow in the morning but i have also to spend some time= with my=20 YL. I hope that can be arranged...
 
On the hill i have= no internet=20 but i will at least inform Markus/DF6NM to give those who are intere= sted a=20 information here...
 
I have to go now, and will inform= =20 you...
 
73,=20 Stefan/DK7FC

________________________________

Von: owner-rsgb_lf_= group@blacksheep.org=20 im Auftrag von Alexander S. Yurkov
Gesendet: Sa 27.02.2010 20:37<= BR>An: rsgb_lf_gro= up@blacksheep.org
Betreff:=20 RE: LF: Fwd: Special Permits for Amateur Radio Operation below=20 9kHz?



> when back in the mid 90's the initial requ= est for a=20 longwave amateur
> segment (what later turned out to be 137kHz= ) was=20 discussed, one of the
> big telecom "bobo's" stated that they= saw no=20 harm that amateurs would
> transmit there with max. 1 W EIRP= as with=20 that power one wouldn't be
> able to get any further than the= other end=20 of the town.
> It turned out a bit different, unless you see= the world=20 as one big town ;-)

Rik, after some theoretical estimations= done i am=20 absolutely shure
QRSS communications at few 100s km (may be more= ) is=20 posible on 9 kHz.
There is lot of problems on TX side but them to= be=20 solvable. Main problem
is high voltage on the TX ANT. I expect 10= 0 - 200 kV=20 is reachable with
some 'tricks' wellknown for power ingeneers. Fo= r example=20 one should avoid
free end of a wire with such a voltage. On shoul= d use=20 'protecting rings'
on the ends. With voltage abt 100 kV seems to= be posible=20 use not too high
antenna. Seems 20-30 m high well top loaded marc= oni=20 designed specially for
high voltage is adequate. Remember effecti= ve height=20 of 60m kite antenna
used in DK8KW experiment was 30m (if wire was= =20 absolutelly vertical, does
it was?). With not too high voltage an= d not too=20 large ANT capacity 4.5 km
was reached. Another key problem is noi= se level=20 on this freq. Now we see
huge discrepancy on the noise level got= from=20 different sourses. What is
the real noise level is not obvious no= w. Can it=20 be much  lower time to
time? Experements to be usefull. Look= at DK8KW=20 web side where 4.5 km
experiment is described. Waterfall backgrou= nd is too=20 smooth. Where
spherics are? This is why i expect RX sensetivity= was not=20 as
high as posible. One should remember 4.5 km is begining of the= wave=20 zone
on 9 kHz. At distanses more then 4.5 km field decreases not= too fast=20 with
distance. Another critical distance is abt 100 km where=20 'waveguide'
propagation starts. At such distances one shold incre= ase TX ANT=20 voltage
only in 3 times to reach distance 10 times more. Anyway= =20 Stefan's
experiment will be very intesesting. And i hope it will= be not the=20 last
experiment.

Regards,
Alexander/RA9MB



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