Return-Path: X-Spam-DCC: paranoid 1170; 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 t4RNR1Xv022257 for ; Thu, 28 May 2015 01:27:01 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Yxkg5-0000Uo-7X for rs_out_1@blacksheep.org; Thu, 28 May 2015 00:24:01 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Yxkg4-0000Uf-I3 for rsgb_lf_group@blacksheep.org; Thu, 28 May 2015 00:24:00 +0100 Received: from omr-m07.mx.aol.com ([64.12.143.81]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.85) (envelope-from ) id 1Yxkg1-0007KU-Lb for rsgb_lf_group@blacksheep.org; Thu, 28 May 2015 00:23:59 +0100 Received: from mtaout-mcb02.mx.aol.com (mtaout-mcb02.mx.aol.com [172.26.50.174]) by omr-m07.mx.aol.com (Outbound Mail Relay) with ESMTP id 5AEB87003547D for ; Wed, 27 May 2015 19:23:55 -0400 (EDT) Received: from White (ipb21bee4a.dynamic.kabel-deutschland.de [178.27.238.74]) by mtaout-mcb02.mx.aol.com (MUA/Third Party Client Interface) with ESMTPA id 04A053800008C for ; Wed, 27 May 2015 19:23:51 -0400 (EDT) Message-ID: From: "Markus Vester" To: References: <394FEA4DA5AA4542828CB5F63AEE2C88@F6CNIToshiba> <474231660.434744.1432735092592.JavaMail.yahoo@mail.yahoo.com> <556640CA.1080101@posteo.de> Date: Thu, 28 May 2015 01:23:50 +0200 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 12.0.1606 X-MimeOLE: Produced By Microsoft MimeOLE V12.0.1606 x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20140625; t=1432769035; bh=kCeWfLY+zmyUkGxv1WwDfhYaQffG81u8/FF90N0JPag=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=tAzJrRhqsDtsAuYy/fVebc/ax8wW6fFioIXL5VpQDWRRjQcpe5F7tGbjdwJoT7xQj SnGV0s7tEXdMgkiIYkU8DLYplTV/MNoUuQlML6XX6UMfnZiotRZNSXcPxnnbKqJNCU U207jExyBzdwi1dVl6ieTsQ2WrwzNNokLJ0LdCMw= x-aol-sid: 3039ac1a32ae556652075c63 X-AOL-IP: 178.27.238.74 X-Scan-Signature: 135a8c1b14bcccf9db1070c2f16443c8 Subject: Re: LF: MF mobile ? Content-Type: multipart/alternative; boundary="----=_NextPart_000_0006_01D098E4.F3C42D70" 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: 3321 Dies ist eine mehrteilige Nachricht im MIME-Format. ------=_NextPart_000_0006_01D098E4.F3C42D70 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable > 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 day = ;-) 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 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 noise, and watching in a "QRSS-60" spectrogram with = 16 mHz (-18 dBHz) noise bandwidth., the noise floor would be -44 dBuV/m, = and we'd achieve 11 dB SNR. Phew, we've made it.... Scaling from LF to MF while maintaining same antenna voltage, current = will be 3.4 times higher, ERP 144 times (ie. 60 uW), and fieldstrength = 12 times.=20 BTW Forget about that parallel 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=20 Sent: Thursday, May 28, 2015 12:10 AM To: rsgb_lf_group@blacksheep.org=20 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 !=20 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:=20 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. The 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. =20 I look forward to hearing about your further experimentation. I hope = you will conduct this test again in the winter. 73! John KB5NJD / WG2XIQ -------------------------------------------------------------------------= ----- From: Guy=C3=A9 Andr=C3=A9 To: RSGB LF Group =20 Sent: Wednesday, May 27, 2015 7:05 AM Subject: LF: Fw: De F6CNI : WSPR Test using mobile on MF to night. 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 ? 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. From: Markus Vester=20 Sent: Tuesday, May 26, 2015 7:06 PM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: De F6CNI : WSPR Test using mobile on MF to night. Great Andy, this is a wonderful experiment!=20 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) =20 -----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. Hi to all. I=E2=80=99ll be testing 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 a.. TX power 2 Watts ;=20 b.. Antenna is a 2 meters long whip ;=20 c.. Total Antenna Z =3D 85 -16610 j. Using base L tuner to 50 Ohms ; = d.. Antenna base current =3D 145 mA, base voltage =3D 2400 Volts RMS = ;=20 e.. Average expected soil up to the Fraunhofer zone : 0.003 S/m and = 13 for dielectric ;=20 f.. Effeciency about =E2=80=93 43 dB. Maxi lobe is -40,5 dBi at = 22=C2=B0 site ;=20 g.. Apparent radiated power is about 150 micro Watt, and the = E.I.R.P. is about 270 micro Watt.=20 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 . -------------------------------------------------------------------------= ----- L'absence de virus dans ce courrier =C3=A9lectronique a = =C3=A9t=C3=A9 v=C3=A9rifi=C3=A9e par le logiciel antivirus Avast.=20 www.avast.com =20 ------=_NextPart_000_0006_01D098E4.F3C42D70 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
> I bet you=20 have all the formulas in your mind :-)

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

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

Hmm, i = find someone=20 should do a real mobile (mobile-mobile, with a velocity > 0) = experiment. A=20 1.5 m long CB antenna with a special preparated feed point should work. = And i=20 think that the wire works better with a fixed C in parallel, even if = this=20 reduces the efficiency. But it stabilises the SWR or better said, the = voltage on=20 the wire. Corona? Where is the problem with corona? :-)
Markus, could = you=20 calculate the ERP when 10 kV rms is applied to a 1.5m high antenna on a = car=20 roof? I bet you have all the formulas in your mind :-)

Maybe the = antenna=20 has 10 pF. I remember i have a 470pF/16kV capacitor at home. So if C =3D = 470 pF=20 and f =3D 475 kHz, L =3D 239 uH With 470 pF parallel to the antenna, a = moving wire=20 (=3D changing C) does not make a significant effect i think.
10 kV at = 239 uH at=20 10 kV is 14A. If P =3D 200 W, the losses must be 1 Ohm !
With a good = RF litz=20 wire, this is possible :-)

What would be the ERP and possible=20 distance?

It would be interesting to try that in WSPR / QRSS-60 = :-) I=20 would also drive to someone for making a CW QSO but most likely there is = a LOT=20 of QRM when driving...

More ideas?

73, = Stefan


Am=20 27.05.2015 15:58, schrieb John Langridge:=20
Andy,

>Perhaps a 2 meters whip is a bit = too short=20 ?

The smallest antenna that I = have=20 experimented with was a base loaded vertical that was almost 3 meters = long and=20 I observed reasonable success with about 100w TPO.  The radiator = was a 2=20 cm diameter aluminum antenna tube so charge was distributed pretty = well and no=20 corona was observed.  There was no additional top loading in the = test.=20   I was using a fair radial system at the time but perhaps its = time to=20 try this same arrangement in a fixed mobile setting as you have done = here.=20  

I look forward to = hearing=20 about your further experimentation.  I hope you will conduct this = test=20 again in the winter.

73!

John KB5NJD / = WG2XIQ

From: Guy=C3=A9 Andr=C3=A9 <andre.guye1@aliceadsl.fr>=
To: RSGB LF Group <rsgb_lf_group@blacksheep= .org>=20
Sent: Wednesday, = May 27,=20 2015 7:05 AM
Subject: LF: Fw:=20 De F6CNI : WSPR Test using mobile on MF to night.

Hello=20 Markus.
 
I am sad about my experiment, only one = station copied=20 my very loud signal last night : F5WK at 72 km. Perhaps a 2 meters = whip is a=20 bit too short ?
 
For a next experiment, F6GEX just give me an = other=20 mobile antenna shape idea. Intesresting indeed ! Be sure, I=E2=80=99ll = give to you=20 also the results of the doppler effect. HI.
 
Best 73 de Andy F6CNI.
 
 
 


From: Markus Vester=20
Sent: Tuesday, May 26, 2015 7:06 PM
To: rsgb_lf_group@blacksheep.= org=20
Subject: Re: LF: De = F6CNI :=20 WSPR Test using mobile on MF to night.
 
Great Andy, this is a wonderful experiment!
 
If you could persuade yourself to drive on a highway while = transmitting,=20 would we be able to measure your speed using Doppler effect? Probably = not=20 using WSPR, but surely with QRSS-60...
 
73, Markus (DF6NM)

 
-----Urspr=C3=BCngliche Mitteilung-----
Von:=20 Guy=C3=A9 Andr=C3=A9 <andre.guye1@aliceadsl.fr>= An: RSGB LF Group <rsgb_lf_group@blacksheep= .org>Verschickt: Di, 26 Mai 2015 1:47 pm
Betreff: LF: De=20 F6CNI : WSPR Test using mobile on MF to night.

Hi to all.
 
I=E2=80=99ll be testing this evening WSPR 2 and at times = WSPR 15 on MF=20 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=20 garden=E2=80=A6
 
  • TX power 2 = Watts=20 ;=20
  • Antenna is = a 2 meters=20 long whip ;
  • Total = Antenna Z =3D 85=20 -16610 j. Using base L tuner to 50 Ohms ;=20
  • Antenna = base current =3D=20 145 mA, base voltage =3D 2400 Volts RMS ;=20
  • Average = expected soil=20 up to the Fraunhofer zone : 0.003 S/m and 13 for dielectric ; =
  • Effeciency = about =E2=80=93 43=20 dB. Maxi lobe is -40,5 dBi at 22=C2=B0 site ;
  • Apparent = radiated=20 power is about 150 micro Watt, and the E.I.R.P. is about 270 micro=20 Watt.
 
Reports be appreciated.
 
Begining the experiment this evening at 2000 TU to next = morning,=20 but I think the best period is around 2300 to 0200 TU.
 
Best 73.
 
Andy - F6CNI =E2=80=93 JN19QB
 
.

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


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