Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dg03.r1000.mx.aol.com (Internet Inbound) with ESMTP id DD4C838000088; Sun, 27 Nov 2011 08:37:45 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1RUeub-0001eQ-3N for rs_out_1@blacksheep.org; Sun, 27 Nov 2011 13:36:53 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1RUeua-0001eH-A8 for rsgb_lf_group@blacksheep.org; Sun, 27 Nov 2011 13:36:52 +0000 Received: from thalia-smout.broadpark.no ([80.202.8.21]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1RUeuY-00027x-DJ for rsgb_lf_group@blacksheep.org; Sun, 27 Nov 2011 13:36:52 +0000 Received: from ignis-smin.broadpark.no ([80.202.8.11]) by thalia-smout.broadpark.no (Sun Java(tm) System Messaging Server 7u3-15.01 64bit (built Feb 12 2010)) with ESMTP id <0LVB00CEMN584Z70@thalia-smout.broadpark.no> for rsgb_lf_group@blacksheep.org; Sun, 27 Nov 2011 14:36:44 +0100 (CET) Received: from [127.0.0.1] ([80.202.132.143]) by ignis-smin.broadpark.no (Sun Java(tm) System Messaging Server 7u3-15.01 64bit (built Feb 12 2010)) with ESMTPA id <0LVB008TIN57KQP0@ignis-smin.broadpark.no> for rsgb_lf_group@blacksheep.org; Sun, 27 Nov 2011 14:36:44 +0100 (CET) Date: Sun, 27 Nov 2011 14:36:43 +0100 From: Steinar Aanesland In-reply-to: <4ED14173.1010307@iup.uni-heidelberg.de> To: rsgb_lf_group@blacksheep.org Message-id: <4ED23CEB.5090807@broadpark.no> MIME-version: 1.0 References: <66E491BAB91C48AF81191F4022525A14@DennisPC> <6FE757960E6C447781689D4F19A315AE@DennisPC> <4EC2C6EB.2080201@iup.uni-heidelberg.de> <4EC2DB14.9000807@talktalk.net> <4ECFD8B6.2050601@iup.uni-heidelberg.de> <4ED0E0EC.9020404@iup.uni-heidelberg.de> <4ED0FE66.2070706@iup.uni-heidelberg.de> <184BB3B594844BF693BC8F53E3BFC8D1@White> <4ED11EFC.1030002@iup.uni-heidelberg.de> <4ED12C77.9030707@broadpark.no> <4ED14173.1010307@iup.uni-heidelberg.de> User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:8.0) Gecko/20111105 Thunderbird/8.0 X-Spam-Score: 1.4 (+) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001,RATWARE_GECKO_BUILD=1.426 Subject: Re: VLF: 8970 Hz transmissions, soon again here Content-type: multipart/alternative; boundary="Boundary_(ID_2HfRFIRoGkDsTNcpsnFs7g)" 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: 0:2:472398464:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d410b4ed23d29678c X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This is a multi-part message in MIME format. --Boundary_(ID_2HfRFIRoGkDsTNcpsnFs7g) Content-type: text/plain; charset=ISO-8859-1 Content-transfer-encoding: QUOTED-PRINTABLE Thanks Stefan , this was impressive!! By the way , are you still transmitting ? la5vna S Den 26.11.2011 20:43, skrev Stefan Sch=E4fer: > Hello Steinar, > > My antenna is a 70m long and 30m high inv-L antenna. The coil is on > the roof, i.e. on the top of the building, see picture in my last > mail. >From my last VLF experiments i built a coil that was designe= d > to resonate a 100m vertical antenna on 8970 Hz, i.e. it has about 5= 50 > mH with a variometer part of arround 30 mH. DC losses of that coil = is > about 320 Ohm, so most of the power ( > 90 %) is lost in the coil. = The > antenna wire is hold on the building with ceramic isolators what ca= n > withstand 36 kV rms in rain/snow/ice/dirt, so if its reasonable dry > and clean i estimate it will withstand 100 kV rms without a problem= . > But the coil is critical! It was quite a lot of work to wind it as = you > can imagine, so i decided to limit the voltage across the coil to 5= 0 > kV rms. > My fixed antenna has about 100 pF less than the 100m kite vertical, > this is why i have to add the external plate capacitor... > I just got 780 mA at 350 W, so the loss resistance is 575 Ohm. As y= ou > can see the coil is standing on the bottom of that building so ther= e > may be significant losses of the magnetic field in the roof/bottom. > But as long as the voltage is the limiting factor i do not care abo= ut > losses since nothing is won if i reduce the losses. The ERP stays > constant then... > > The TX frequency is generated in my PC, using SpecLab as the freque= ncy > generator, locking to a 10 kHz reference signal coming from my GPS > module. Signal is fed through a fiber optic cable to prevent any EM= C > problems.... > > The signal is still running without any interruptions. There seemed= to > be a phase glitch arround 17:15 UTC but since that time the frequen= cy > seems to be pretty clear. My "DFCW-60" grabber window is a good > indicator to check that: > http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber.htm= l > BTW i'm using a different GPS module for the TX notebook, the grabb= er > runs its own module. So if a phase glitch becomes visible there, it > could also come from my RX (i.e. the VLF grabber PC). > > 73, Stefan/DK7FC > > > Am 26.11.2011 19:14, schrieb Steinar Aanesland: >> >> Stefan >> >> You have probably mention this some place, but please repeat it me= , >> what kind of antenna are you using now ? >> >> la5vna S >> >> >> Den 26.11.2011 18:16, skrev Stefan Sch=E4fer: >>> VLF, >>> >>> >>> Am 26.11.2011 17:55, schrieb Markus Vester: >>>> Once more, Paul Nicholson is showing a good trace: >>>> =20 >>>> http://abelian.org/vlf/fbins.shtml#p=3D1322319600&b=3D120&s=3Dsp >>>> >>> >>> Wow, yes, very good! >>> >>> Well, the system runs on the GPS locked system now since 17:00 UT= C >>> and i'm running 780 mA on 8970.00000 Hz. Will go for dinner now a= nd >>> leave the system running some hours. The WX looks quite useful, n= o >>> rain, poor wind and no fog! Maybe i will even run it overnight un= til >>> tomorrow, transmitting a streight carrier at 350 W RF. Can't do m= ore >>> unfortunately, due to the cola-cap ;-) >>> >>> Now as the signal is locked and non-drifting there may come up >>> something on the 6000-windows... >>> >>> Maybe Paul or others can do some calculations, estimating the ERP= ? I >>> think it should be in the range of 200 uW. Up to 6 dB can be adde= d >>> in further tests, i hope. >>> Markus, a S/N (better S and N ;-) ) plot on your side would be >>> interesting. My ERP should be constant now so we can observe the >>> QSB, caused by propagation... >>> >>> A photo of the todays arrangement: >>> http://dl.dropbox.com/u/19882028/VLF/DSC04268.JPG >>> >>> 73, GL, Stefan/DK7FC >>> >>> >>> >>> >>> >>> >>>> =20 >>>> ... well done! >>>> =20 >>>> Markus >>>> =20 >>>> *From:* Markus Vester >>>> *Sent:* Saturday, November 26, 2011 4:33 PM >>>> *To:* rsgb_lf_group@blacksheep.org >>>> >>>> *Subject:* Re: VLF: 8970 Hz transmissions, soon again here >>>> >>>> Stefan, >>>> =20 >>>> around 15:00, your sig on 8970.008 was visible in >>>> Nuernberg, peaking ~ 20 dB SNR in 0.48 mHz. >>>> =20 >>>> Viel Gl=FCck, >>>> Markus (DF6NM) >>>> >>>> *From:* Stefan Sch=E4fer >>>> *Sent:* Saturday, November 26, 2011 3:57 PM >>>> *To:* rsgb_lf_group@blacksheep.org >>>> >>>> *Cc:* Paul >>>> *Subject:* Re: VLF: 8970 Hz transmissions, soon again here >>>> >>>> VLF, >>>> >>>> I'm now running 350W into the system and get about 0.8 A antenna >>>> current. Strong audible partial discharges occurr on a parallel = fixed >>>> plate capacitor, spaced by 3 cola bottles (0.33l ;-) ). At 550 m= H i >>>> have >>>> 25 kV rms on the antenna and coil which seems to be no problem a= t all. >>>> >>>> The frequency is still a bit unstable since i took the DDS VFO >>>> which is >>>> more comfortable to find the resonance. I will now try to slight= ly QRO >>>> and then apply a fiber optic cable carrying the GPS locked frequ= ency >>>> coming from the PC/SpecLab, hopefully without to many phase glit= ches. >>>> Currently i may have an offset of some 20...30 mHz and a slight = drift >>>> but it is a first successfully test :-) >>>> >>>> 73, Stefan/DK7FC >>>> >>>> >> --Boundary_(ID_2HfRFIRoGkDsTNcpsnFs7g) Content-type: text/html; CHARSET=US-ASCII Content-transfer-encoding: QUOTED-PRINTABLE
Thanks Stefan , this was impressive!!

By the way , are you still transmitting ?


la5vna S





Den 26.11.2011 20:43, skrev Stefan Schäfer:
Hello Steinar,

My antenna is a 70m long and 30m high inv-L antenna. The coil i= s on the roof, i.e. on the top of the building, see picture in my last mail. >From my last VLF experiments i built a coil that was design= ed to resonate a 100m vertical antenna on 8970 Hz, i.e. it has about = 550 mH with a variometer part of arround 30 mH. DC losses of that coil= is about 320 Ohm, so most of the power ( > 90 %) is lost in the coil. The antenna wire is hold on the building with ceramic isolators what can withstand 36 kV rms in rain/snow/ice/dirt, so if its reasonable dry and clean i estimate it will withstand 100 kV rms without a problem. But the coil is critical! It was quite a lot of work to wind it= as you can imagine, so i decided to limit the voltage across the coil = to 50 kV rms.
My fixed antenna has about 100 pF less than the 100m kite vertical, this is why i have to add the external plate capacitor...
I just got 780 mA at 350 W, so the loss resistance is 575 Ohm. = As you can see the coil is standing on the bottom of that building so there may be significant losses of the magnetic field in the roof/bottom. But as long as the voltage is the limiting factor i do not care abo= ut losses since nothing is won if i reduce the losses. The ERP sta= ys constant then...

The TX frequency is generated in my PC, using SpecLab as the frequency generator, locking to a 10 kHz reference signal coming from my = GPS module. Signal is fed through a fiber optic cable to prevent an= y EMC problems....

The signal is still running without any interruptions. There seemed to be a phase glitch arround 17:15 UTC but since that time the frequency seems to be pretty clear. My "DFCW-60" grabber window is a good indicator to check that: http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grab= ber.html BTW i'm using a different GPS module for the TX notebook, the grabber runs its own module. So if a phase glitch becomes visible there= , it could also come from my RX (i.e. the VLF grabber PC).

73, Stefan/DK7FC


Am 26.11.2011 19:14, schrieb Steinar Aanesland:

Stefan

You have probably mention this some place, but please repeat = it me, what kind of antenna are you using now ?

la5vna S


Den 26.11.2011 18:16, skrev Stefan Schäfer:
VLF,


Am 26.11.2011 17:55, schrieb Markus Vester:
Once more, Paul Nicholson is showing a good trace: =
 

Wow, yes, very good!

Well, the system runs on the GPS locked system now since 17= :00 UTC and i'm running 780 mA on 8970.00000 Hz. Will go for dinner now and leave the system running some hours. The WX looks quite useful, n= o rain, poor wind and no fog! Maybe i will even run it overnight until tomorrow, transmitting a streight carrier at 350 W RF. Can't do more unfortunately, due to the cola-cap ;-)

Now as the signal is locked and non-drifting there may come= up something on the 6000-windows...

Maybe Paul or others can do some calculations, estimating t= he ERP? I think it should be in the range of 200 uW. Up to 6 dB can b= e added in further tests, i hope.
Markus, a S/N (better S and N ;-) ) plot on your side would= be interesting. My ERP should be constant now so we can observ= e the QSB, caused by propagation...

A photo of the todays arrangement: http://dl.dropbox.com/u/19882028/VLF/DSC04268.JPG

73, GL, Stefan/DK7FC






 
... well done!
 
Markus
 
Sent: Saturday, November 26, 2011 4:33 PM=
Subject: Re: VLF: 8970 Hz transmissions, soon again here

Stefan,
 
around 15:00, your sig on 8970.008 was visible= in Nuernberg, peaking ~ 20 dB SNR in 0.48 mHz.
 
Viel Glück,
Markus (DF6NM)

VLF,

I'm now running 350W into the system and get about 0.8 A antenna
current. Strong audible partial discharges occurr on a parallel fixed
plate capacitor, spaced by 3 cola bottles (0.33l ;-) ). A= t 550 mH i have
25 kV rms on the antenna and coil which seems to be no problem at all.

The frequency is still a bit unstable since i took the DD= S VFO which is
more comfortable to find the resonance. I will now try to slightly QRO
and then apply a fiber optic cable carrying the GPS locke= d frequency
coming from the PC/SpecLab, hopefully without to many pha= se glitches.
Currently i may have an offset of some 20...30 mHz and a slight drift
but it is a first successfully test :-)

73, Stefan/DK7FC




--Boundary_(ID_2HfRFIRoGkDsTNcpsnFs7g)--