Return-Path: X-Spam-DCC: paranoid 1233; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.4 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_MESSAGE autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id t4SE1x0G024034 for ; Thu, 28 May 2015 16:01:59 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1YxyI4-0002kx-Sy for rs_out_1@blacksheep.org; Thu, 28 May 2015 14:56:08 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1YxyI4-0002ko-9T for rsgb_lf_group@blacksheep.org; Thu, 28 May 2015 14:56:08 +0100 Received: from nm17-vm1.bullet.mail.bf1.yahoo.com ([98.139.213.55]) by relay1.thorcom.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.85) (envelope-from ) id 1YxyI0-0001lK-KO for rsgb_lf_group@blacksheep.org; Thu, 28 May 2015 14:56:07 +0100 X-DKIM-Result: Domain=sbcglobal.net Result=Signature OK DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sbcglobal.net; s=s2048; t=1432821362; bh=Ge72Lo5nk0ZxLP5xO1xARoU7Qyacc4lZlDFJkcjiuVo=; h=Date:From:Reply-To:To:In-Reply-To:References:Subject:From:Subject; b=LSQ0eercoZfxfWFP6ty5/9UPzEY/049/Hw86/xOL9CdOW48ME1RG7PrvXVtlkWkNdPx39jckM6IAVXo6/AhIDzctcWn44v5ZEC0HGnPIwXVZzQtM1VhdnPH6f6/1WzJ0k5s9fZyHlzx2L/iN/cJaED9fTs/YKeZ/Jpb6AjESswvTLyVq1Xi0TMkE8tif9CohutWUrkwAZ4gK/j7m7IyDfhSd531Tn97e5mCS/9w1Spt04LmKTfwffBHFY6FpxBHwX5d07Mq+pDzfyR1qDu3HylqUWaSxlFe4+0Kb3a5BUs+PKlFf2eoOkw5393B45MR+eeBQ+q5xO0XCvpyV2WHSTQ== Received: from [98.139.214.32] by nm17.bullet.mail.bf1.yahoo.com with NNFMP; 28 May 2015 13:56:01 -0000 Received: from [98.139.212.238] by tm15.bullet.mail.bf1.yahoo.com with NNFMP; 28 May 2015 13:56:01 -0000 Received: from [127.0.0.1] by omp1047.mail.bf1.yahoo.com with NNFMP; 28 May 2015 13:56:01 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 967967.79144.bm@omp1047.mail.bf1.yahoo.com X-YMail-OSG: NPbW5csVM1k2ii4zzmzUCzAZ4S.VNJ5tMLB7jv6UQcEP1MBD6Xl5w0nLsIcu9hh dm8GHSFmB20AE9UMKiqHcBI1jMAHxhH9MJge9vaYJBAHsEfqgqoYs8Y5F7ALFckNTy3ofsQRSZop UPGNPsUF3qfC6ZmZ2fEcEoYZRbb1OTtEQDuUWuXaIYSawp4xTEPguai9o2Siz_EHFT7TIwGZPPDV DCYnVO0s7lfForSzUoorU.UACUt3tgc1x5_WWoR6H99gkFH.azaKd786tTr6T31IDoL.0TnUn71W kLoAuy8v.ERwc8885q8CD297YGOQPI.2AfPlnvdP6xSYivE6XdwddBRbVKDTYHjvI0A_.pw0KPO9 e8nXH4rjpGHFR7oEQNKCVh1FQLiFDtBOmHfTIbhR1zDfrKOT3AJllFEAU0AcxpFJMiyg5Au6RC4n PEta_.f_.j.sWIdPfPqQjXUJ7L82upa9mlNp96VoL2rIQgRJ81n3pmbqRhB0eOwExcix0qpqNHwx h5Z3AAbAJCJisnbOijVJjoYIH2CNGbSg- Received: by 66.196.80.121; Thu, 28 May 2015 13:56:01 +0000 Date: Thu, 28 May 2015 13:55:59 +0000 (UTC) From: John Langridge To: "rsgb_lf_group@blacksheep.org" Message-ID: <737383395.482640.1432821359446.JavaMail.yahoo@mail.yahoo.com> In-Reply-To: <55665743.2080809@posteo.de> References: <55665743.2080809@posteo.de> MIME-Version: 1.0 X-Scan-Signature: 1c1810732145343628345049e9818a40 Subject: Re: LF: MF mobile ? Content-Type: multipart/alternative; boundary="----=_Part_482639_333088986.1432821359422" 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-Scanned-By: MIMEDefang 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 3335 ------=_Part_482639_333088986.1432821359422 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable >But you need to consider the changing angle of the wire whiledriving.=20 I've always felt like the match change due to antenna angle could be regula= ted in realtime with a motorized vario or other matching elements controlle= d with an arduino or comparable platform, possibly using scopematch-style s= ensing... So as the match changes due to speed, crosswinds, etc, the match = could be touched up.=C2=A0 Thats a lot going on on the roof of a moving veh= icle but seems reasonable enough for many adventerous souls. The NPRM for 630m here in the US does not allow for true mobile operation a= s it currently stands but its nice to be able to live vicariously through c= olleagues around the world. 73! John KB5NJD / WG2XIQ.. From: DK7FC To: rsgb_lf_group@blacksheep.org=20 Sent: Wednesday, May 27, 2015 6:46 PM Subject: Re: LF: MF mobile ? =20 Ah, sorry, i didn't read your mail until the end.=20 OK about your argumentation and of course i know that from the VLFtimes :-)= But you need to consider the changing angle of the wire whiledriving. If C= is just 10 pF, this can vary by +20 % i expect. And thiswill change the re= sonance. If you are out of resonance, the voltagedrops and then there is un= wanted fading. If the limiting factor is thevoltage, not the TX power (with= in certain limits of course :-) ), thena parallel C will help here i find. I have been active on 40m CW /m and i know the SWR can vary quitestrong. OK, if i go down from 470 pF to 100 pF, L will be 4.7 times higher andso th= e current needs to be 4.7 times smaller to achieve 10 kV again.OK, 3 A soun= ds easier than 14 A. But i would need about 1 mH for thecoil. That is a bet= ter decision.=20 To many projects now here! What about you?!=20 73, Stefan Am 28.05.2015 01:33, schrieb DK7FC: =20 Sorry Markus, can you do all the calculations again for 475 kHz ? :-) =20 73, Stefan =20 Am 28.05.2015 01:23, schrieb Markus Vester:=20 =20 >I bet you have all the formulas in your mind :-) =20 Yes Stefan, sure do... this is the kind of stuff I sometimes like tothink a= bout during my=C2=A0bike ride to work - about 70 minutes, twice a day;-) Ok= , no pocket calculator allowed then... =C2=A0 A 1.5 m stick would have=C2= =A0about=C2=A010pFor -j 120 kohm at 137 kHz.=C2=A0If you're keen you could = probably go up to20 kV,=C2=A0giving 0.16 A. Effective height will be=C2=A0a= round 0.7m, soradiation resistance is 1579ohms*(.7/2200)^2 =3D 160 microohm= s. Thusradiated power =3D 0.0256=C2=A0* 160 =3D 0.4=C2=A0microwatt or -34 d= Bm. =C2=A0 Assuming a coil Q of 400, requiredTX power would be only 0.16^2 = * 120k / 400=C2=A0=3D 8 watts. If you're not afraid of non-ionizing E-field= syou=C2=A0could probably do that from a bicycle (sic), or walking around=C2= =A0witha=C2=A0backpack=C2=A0;-) =C2=A0 At a range of 180 km between us,we'd= get=C2=A0a groundwave fieldstrength of=C2=A050-34-45-4 dBuV/m =3D -33dBuV/= m.=C2=A0Assuming a quiet day with=C2=A0of -26 dBuV/m/Hz background noise,an= d watching=C2=A0in a "QRSS-60" spectrogram with=C2=A016 mHz (-18 dBHz)=C2= =A0noisebandwidth., the noise floor would be -44 dBuV/m, and we'd achieve 1= 1 dBSNR. Phew, we've made it.... =C2=A0 Scaling from LF to MF whilemaintain= ing=C2=A0same antenna voltage,=C2=A0current will be 3.4 times higher,=C2=A0= ERP144 times (ie. 60 uW), and fieldstrength 12 times.=C2=A0 =C2=A0 BTW=C2= =A0Forget about that=C2=A0parallelcapacitor to reduce tuning variation - th= at would be just cheatingyourself, similar to adding an attenuator after th= e TX to improvematching.=C2=A0Only the=C2=A0current going into the actual a= ntenna=C2=A0is the onethat's radiating. =C2=A0 All the best, Markus =C2=A0= =20 From: DK7FC Sent: Thursday, May 28, 2015 12:10 AM To: rsgb_lf_group@bl= acksheep.org Subject: LF: MF mobile ? =20 Hmm, i find someone should do a real mobile (mobile-mobile, with avelocity= > 0) experiment. A 1.5 m long CB antenna with a specialpreparated feed poi= nt should work. And i think that the wire worksbetter with a fixed C in par= allel, even if this reduces the efficiency.But it stabilises the SWR or bet= ter said, the voltage on the wire.Corona? Where is the problem with corona?= :-) Markus, could you calculate the ERP when 10 kV rms is applied to a 1.5mhigh= antenna on a car roof? I bet you have all the formulas in yourmind :-) =20 Maybe the antenna has 10 pF. I remember i have a 470pF/16kV capacitorat hom= e. So if C =3D 470 pF and f =3D 475 kHz, L =3D 239 uH With 470 pFparallel t= o the antenna, a moving wire (=3D changing C) does not make asignificant ef= fect i think. 10 kV at 239 uH at 10 kV is 14A. If P =3D 200 W, the losses must be 1 Ohm!= =20 With a good RF litz wire, this is possible :-) =20 What would be the ERP and possible distance? =20 It would be interesting to try that in WSPR / QRSS-60 :-) I would alsodrive= to someone for making a CW QSO but most likely there is a LOT ofQRM when d= riving... =20 More ideas? =20 73, Stefan =20 =20 Am 27.05.2015 15:58, schrieb John Langridge:=20 Andy,=20 >Perhaps a 2 meters whip is a bittoo short ?=20 The smallest antennathatI have experimented with was a base loaded vertic= al that was almost 3meters long and I observed reasonable success with abou= t 100w TPO. =C2=A0Theradiator was a 2 cm diameter aluminum antenna tube so = charge wasdistributed pretty well and no corona was observed. =C2=A0There w= as noadditional top loading in the test. =C2=A0 I was using a fair radial s= ystemat the time but perhaps its time to try this same arrangement in afixe= d mobile setting as you have done here. =C2=A0=20 I lookforwardto hearing about your further experimentation. =C2=A0I hope = you will conductthis test again in the winter.=20 73!=20 John KB5NJD /WG2XIQ=20 From: Guy=C3=A9 Andr=C3=A9 To: RSGB LF Group =20 Sent: Wednesday,May27, 2015 7:05 AM Subject: LF: Fw:DeF6CNI : WSPR Test using mobile on MF to night. =20 HelloMarkus. =C2=A0 I am sadabout my experiment, only one station c= opied my very loud signal lastnight : F5WK at 72 km. Perhaps a 2 meters whi= p is a bit too short ? =C2=A0 For a nextexperiment, F6GEX just give me an o= ther mobile antenna shape idea.Intesresting indeed ! Be sure, I=E2=80=99ll = give to you also the results of thedoppler effect. HI. =C2=A0 Best 73 deAnd= y F6CNI. =C2=A0 =C2=A0 =C2=A0=20 =20 From: Markus Vester Sent: Tuesday, May 26, 2015 7:06 PM To: rsgb_lf_gr= oup@blacksheep.org Subject: Re: LF:De F6CNI : WSPR Test using mobile on MF= to night. =C2=A0 Great Andy, this is a wonderful experiment! =C2= =A0 If you could persuade yourself to drive on a highway whiletransmitting,= would we be able to measure your speed using Dopplereffect? Probably not u= sing WSPR, but surely with QRSS-60... =C2=A0 73, Markus (DF6NM)=20 =20 =C2=A0-----Urspr=C3=BCngliche Mitteilung-----=20 Von: Guy=C3=A9 Andr=C3=A9 An: RSGB LF Group Verschickt: Di, 26 Mai 2015 1:47 pm Betreff: LF: De F6CNI : WSPR Test using mobile on MF to night. =20 Hi to all. =C2=A0 I=E2=80=99ll be testing thisevening WSPR 2 and at ti= mes WSPR 15 on MF using a short mobile antenna.My call be F6CNI/M. =C2=A0 O= f course, Idon=E2=80=99t drive my car, it is resting in my garden=E2=80=A6 = =C2=A0 =20 - TX power 2Watts ;=20 - Antenna is a2 meters long whip ; =20 - TotalAntenna Z =3D 85 -16610 j. Using base L tuner to 50 Ohms ;=20 - Antenna basecurrent =3D 145 mA, base voltage =3D 2400 Volts RMS ;=20 - Averageexpected soil up to the Fraunhofer zone : 0.003 S/m and 13 ford= ielectric ;=20 - Effeciencyabout =E2=80=93 43 dB. Maxi lobe is -40,5 dBi at 22=C2=B0 si= te ; =20 - Apparentradiated power is about 150 micro Watt, and the E.I.R.P. is ab= out 270micro Watt.=20 =C2=A0 Reports beappreciated. =C2=A0 Begining theexperiment this evening a= t 2000 TU to next morning, but I think thebest period is around 2300 to 020= 0 TU. =C2=A0 Best 73. =C2=A0 Andy - F6CNI=E2=80=93 JN19QB =C2=A0 . = =20 =20 =20 | | L'absence de virusdansce courrier =C3=A9lectronique a =C3=A9t=C3=A9 = v=C3=A9rifi=C3=A9e par le logiciel antivirusAvast.=20 www.avast.com | =20 =20 =20 =20 =20 ------=_Part_482639_333088986.1432821359422 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
>But you need to consider the changing angle of = the wire while driving.

I've al= ways felt like the match change due to antenna angle could be regulated in = realtime with a motorized vario or other matching elements controlled with = an arduino or comparable platform, possibly using scopematch-style sensing.= .. So as the match changes due to speed, crosswinds, etc, the match could b= e touched up.  Thats a lot going on on the roof of a moving vehicle bu= t seems reasonable enough for many adventerous souls.

The NPRM for 630m here in the US does not = allow for true mobile operation as it currently stands but its nice to be a= ble to live vicariously through colleagues around the world.

73!

John KB5NJD / WG2XIQ..

From: DK7FC <selberdenken@posteo= .de>
To: rsgb_lf_gr= oup@blacksheep.org
Sent:<= /b> Wednesday, May 27, 2015 6:46 PM
Subject: Re: LF: MF mobile ?

Ah, sorry, i didn't read your mail until the end.
OK about your argumentation and of course i know that from the VLF times :-) But you need to consider the changing angle of the wire while driving. If C is just 10 pF, this can vary by +20 % i expect. And this will change the resonance. If you are out of resonance, the voltage drops and then there is unwanted fading. If the limiting factor is the voltage, not the TX power (within certain limits of course :-) ), then a parallel C will help here i find.
I have been active on 40m CW /m and i know the SWR can vary quite strong.
OK, if i go down from 470 pF to 100 pF, L will be 4.7 times higher and so the current needs to be 4.7 times smaller to achieve 10 kV again. OK, 3 A sounds easier than 14 A. But i would need about 1 mH for the coil. That is a better decision.
To many projects now here! What about you?!

73, Stefan

Am 28.05.2015 01:33, schrieb DK7FC:


Sorry Markus, can you do all the calculations again for 475 kHz ? :-)

73, Stefan

Am 28.05.2015 01:23, schrieb Markus Vester:
> I bet you have all the formulas in your mind :-)

Yes Stefan, sure do... this is the kind of stuff I sometimes like to think about during my bike ride to work - about 70 minutes, twice a da= y ;-) Ok, no pocket calculator allowed then...
 
A 1.5 m stick would have = ;about 10 pF or -j 120 kohm at 137 kHz. If you're keen you could probably go up to 20 kV, giving 0.16 A. Effective height will be around 0.7m, so radiation resistance is 1579ohms*(.7/2200)^2 =3D 160 microohms. Thus radiated power =3D 0.0256 * 160 =3D 0.4 microwatt or -34 dBm.
 
Assuming a coil Q of 400, required TX power would be only 0.16^2 * 120k / 400 =3D 8 watts. If you're not afraid of non-ionizing E-fields you could probably do that from a bicycle (sic), or walking around&nbs= p;with a backpack ;-)
 
At a range of 180 km between us, we'd get a groundwave fieldstrength of 50-34-45-4 dBuV/m =3D -33 dBuV/m. Assuming a quiet day with of -26 dBuV/m/Hz background noi= se, and watching in a "QRSS-60" spectrogram with 16 mHz (-18 dBHz)&nb= sp;noise bandwidth., the noise floor would be -44 dBuV/m, and we'd achieve 11 dB SNR. Phew, we've made it....<= /div>
 
Scaling from LF to MF while maintaining same antenna voltage, current will be 3.4 times highe= r, ERP 144 times (ie. 60 uW), and fieldstrength 12 times. 
 
BTW Forget about that pa= rallel capacitor to reduce tuning variation - that would be just cheating yourself, similar to adding an attenuator after the TX to improve matching. Only the current going into the actual antenna is = the one that's radiating.
 
All the best,
Markus
 

From: DK7FC
Sent: Thursday, May 28, 2015 12:10 AM
Subject: LF: MF mobile ?

Hmm, i find someone should do a real mobile (mobile-mobile, with a velocity > 0) experiment. A 1.5 m long CB antenna with a special preparated feed point should work. And i think that the wire works better with a fixed C in parallel, even if this reduces the efficiency. But it stabilises the SWR or better said, the voltage on the wire. Corona? Where is the problem with corona? :-)
Markus, could you calculate the ERP when 10 kV rms is applied to a 1.5m high antenna on a car roof? I bet you have all the formulas in your mind :-)

Maybe the antenna has 10 pF. I remember i have a 470pF/16kV capacitor at home. So if C =3D 470 pF and f =3D 475 kHz, L =3D 239 uH With 470 pF parallel to the antenna, a moving wire (=3D changing C) does not make a significant effect i think.
10 kV at 239 uH at 10 kV is 14A. If P =3D 200 W, the losses must be 1 Ohm !
With a good RF litz wire, this is possible :-)

What would be the ERP and possible distance?

It would be interesting to try that in WSPR / QRSS-60 :-) I would also drive to someone for making a CW QSO but most likely there is a LOT of QRM when driving...

More ideas?

73, Stefan


Am 27.05.2015 15:58, schrieb John Langridge:
= Andy,
=
= >Perhaps a 2 meters whip is a bit too short ?
=
The smallest= antenna that I have experimented with was a base loaded vertical that was almost 3 meters long and I observed reasonable success with about 100w TPO.  Th= e radiator was a 2 cm diameter aluminum antenna tube so charge was distributed pretty well and no corona was observed.  There was no additional top loading in the test.   I was using a fair radial system at the time but perhaps its time to try this same arrangement in a fixed mobile setting as you have done here.  

= I look forward to hearing about your further experimentation.  I hope you will conduc= t this test again in the winter.

73!

= John KB5NJD / WG2XIQ


Hello Markus.
 
I am sad about my experiment, only one station copied my very loud signal last night : F5WK at 72 km. Perhaps a 2 meters whip is a bit too short ?<= /div>
 
For a next experiment, F6GEX just give me an other mobile antenna shape idea. Intesresting indeed ! Be sure, I=E2=80=99ll give to you also the results of= the doppler effect. HI.
 
Best 73 de Andy F6CNI.
 
3D"image=
 
Great Andy, this is a wonderful experiment!
 
If you could persuade yourself to drive on a highway while transmitting, would we be able to measure your speed using Doppler effect? Probably not using WSPR, but surely with QRSS-60...
 
73, Markus (= DF6NM)


 
-----Urspr=C3=BCngliche Mitteilung-----
Von: Guy=C3=A9 Andr=C3=A9 <andre.guye1@= aliceadsl.fr>
An: RSGB LF Group <rsgb_lf_grou= p@blacksheep.org>
Verschickt: Di, 26 Mai 2015 1:47 pm
Betreff: LF: De F6CNI : WSPR Test using mobile on MF to night.

Hi to all.
 
I=E2=80=99ll be te= sting this evening WSPR 2 and at times WSPR 15 on MF using a short mobile antenna. My call be F6CNI/M.
 
Of course, I don=E2=80=99t drive my car, it is resting in my garden=E2=80=A6
 
  • TX power 2 Watts ;
  • Antenna is a 2 meters long whip ;
  • T= otal Antenna Z =3D 85 -16610 j. Using base L tuner to 50 Ohms ;
  • Antenna base current =3D 145 mA, base voltage =3D 2400 Volts RMS ;
  • Average expected soil up to the Fraunhofer zone : 0.003 S/m and 13 for dielectric ;
  • Effeciency about =E2=80=93 43 dB. Maxi lobe is -40,5 dBi at 22=C2=B0 site ;
  • Apparent radiated power is about 150 micro Watt, and the E.I.R.P. is about 270 micro Watt.
 
Reports be appreciated.
 
Begining the experiment this evening at 2000 TU to next morning, but I think the best period is around 2300 to 0200 TU.
 
Best 73.
 
Andy - F6CNI =E2=80=93 JN19QB
 
.


=
3D"Avast
L'absence de virus dans ce courrier =C3=A9lectronique a =C3=A9t=C3=A9 v=C3=A9rifi=C3=A9e par le log= iciel antivirus Avast.
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=20


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