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[195.171.43.25]) by mx.google.com with ESMTP id dc3si12499286wjb.133.2013.12.26.23.24.12 for ; Thu, 26 Dec 2013 23:24:13 -0800 (PST) Received-SPF: neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) client-ip=195.171.43.25; Authentication-Results: mx.google.com; spf=neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) smtp.mail=owner-rsgb_lf_group@blacksheep.org; dkim=pass (test mode) header.i=@comcast.net Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1VwRIV-0004Va-Ek for rs_out_1@blacksheep.org; Fri, 27 Dec 2013 06:53:27 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1VwRIT-0004VR-VR for rsgb_lf_group@blacksheep.org; Fri, 27 Dec 2013 06:53:25 +0000 Received: from qmta11.emeryville.ca.mail.comcast.net ([76.96.27.211]) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1VwRIN-0000ul-C4 for rsgb_lf_group@blacksheep.org; Fri, 27 Dec 2013 06:53:24 +0000 Received: from omta06.emeryville.ca.mail.comcast.net ([76.96.30.51]) by qmta11.emeryville.ca.mail.comcast.net with comcast id 6WpW1n00216AWCUABWtGYG; Fri, 27 Dec 2013 06:53:16 +0000 Received: from Owner ([166.137.182.216]) by omta06.emeryville.ca.mail.comcast.net with comcast id 6Wsu1n00H4gYbxS8SWt0fR; Fri, 27 Dec 2013 06:53:10 +0000 From: "hvanesce" To: References: <2f507c1ff91346b2b8adba0518611224@kabelmail.de> <39966C71EF4543899F81399598C190F7@Extensa> <52BBFDC4.3010507@psk31.plus.com>,<52BC272F.7040803@iup.uni-heidelberg.de> ,<52BC683B.5030107@iup.uni-heidelberg.de> ,<52BC78F9.4000206@iup.uni-heidelberg.de> ,<02b601cf0287$e6429f00$b2c7dd00$@comcast.net> In-Reply-To: Date: Thu, 26 Dec 2013 23:52:51 -0700 Message-ID: <031501cf02d0$4c61ba80$e5252f80$@comcast.net> MIME-Version: 1.0 X-Mailer: Microsoft Outlook 14.0 Thread-Index: AQF4gPz2ZsKVrt05Wvg22cCZ2bAEHQIVWltfAe40wD4CAiw8mQCLmYQeAIqD1XoCL62U6gLbUZ6UAddNmCUCZNpcSwLPSUL1mnr6zsA= Content-Language: en-us DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net; s=q20121106; t=1388127196; bh=eer8FCM6p7QV9jv313IHoiEbQgLML+noxog8Sfch8eg=; h=Received:Received:From:To:Subject:Date:Message-ID:MIME-Version: Content-Type; b=WGk56AGTLompRhQmymrqtJi+R5E6TDyJ55jtA13JZ2v3jHgtPgkJ0LiA2K0q1z0j9 rCm76GqkHWkrwJXiNV3X5Sacw1BeH8/XocZhRhFD6jy2FM/ELsc145NKZ4juiXhsoO lcYteUldJICl8kGQaXJFqHSVTA0lQF9A6QXD0+0ULPslxXeepkeo5dtunFs91+Qqyd IF5D63fzAoik/dIE8u3/Nnm2L4y+3sLfM+cAUmFhN09JoK9omSxWnvHxu9OhIlCwQB R7+GN4eAGUsjOnY/NxMeqWdCXqjPoFG6IYe5ciq+6vmepzSbrLhIBnOHtHn1k3tpaW NlTJR1GKLuf5g== X-Spam-Score: 1.1 (+) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Bob, Thanks for the feedback, sounds like you have corona well-managed on the coil. For future reference, in case someone in the group has an outdoor HV application in a particularly humid environment wherein operation without maintenance is particularly desirable: [...] Content analysis details: (1.1 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [76.96.27.211 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (hvanesce[at]comcast.net) 1.6 SUBJ_ALL_CAPS Subject is all capitals -0.0 SPF_PASS SPF: sender matches SPF record -0.6 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: 76d9bc79bd6387ba51a2380ecf8bbed1 Subject: RE: VLF: 8969.99 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0316_01CF0295.A004DE50" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.4 required=5.0 tests=HTML_30_40,HTML_MESSAGE, SUBJ_ALL_CAPS 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 Status: O X-Status: X-Keywords: X-UID: 1775 This is a multipart message in MIME format. ------=_NextPart_000_0316_01CF0295.A004DE50 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Bob, Thanks for the feedback, sounds like you have corona well-managed on the coil. For future reference, in case someone in the group has an outdoor HV application in a particularly humid environment wherein operation without maintenance is particularly desirable: There are inexpensive lightweight encapsulation materials and encapsulation methods that will allow long-term maintenance-free HV outdoor operation in high humidity. The humidity resistance of most high-humidity HV insulation materials degrades with time and temperature cycling; a small subset of these hold up over time and temperature cycling in humid environments; an even smaller subset is also lightweight and inexpensive. Unfortunately this small subset of inexpensive long-term robust outdoor high-humidity solutions is difficult to repair or rework if such becomes necessary. This is why, for low-cost lightweight outdoor HV equipment, we liked to develop outdoor-application HV electronics in Fluorinert until turns ratios, inductances, winding losses, spacings, coil form size/weight and other factors were just right (with Flourinert one can make winding changes and test in minutes), and then apply the long-term robust encapsulant. The above doesn't matter for your application, since in your application the issues are at the HV output end and beyond, and those localized problem sites can be managed with spheres. Nor does it matter for Stefan's application, since Stephan's coil does not remain outdoors between tests. The above is useful for equipment that remains outdoors in high humidity environments. For most low-cost lightweight HV insulation materials, the humidity threshold of corona inception declines over weeks and months of diurnal temperature cycling in high humidity environments; the solutions impervious to this degradation don't accommodate quick rework, and Fluorinert makes this rework easy until the bugs are out and optimization is complete, at which time an inexpensive lightweight high-humidity outdoor HV encapsulant with 10-year life can be applied. Apologies for the digression from your theme; I thought this might come in handy for future generations of unattended/remote VLF equipment, and thought I'd better write it down while it was in mind. Looking forward to your next step in LF! 73, Jim AA5BW From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Bob Raide Sent: Thursday, December 26, 2013 4:12 PM To: rsgb_lf_group@blacksheep.org Subject: RE: VLF: 8969.99 Jim; I see it's a liquid that is really a coolant. I use clear lacquer and corona dope in a spray can and spray coils with it. I use Stefan's round brass balls that I have soldered to any point that shows signs of corona arcing. It's at the high voltage end of the coil that starts causing trouble and from that point onward. Fluorinert would be great for an item that had high voltages and large amounts of heat present to submerge the item in it-Bob _____ From: hvanesce@comcast.net To: rsgb_lf_group@blacksheep.org Date: Thu, 26 Dec 2013 15:14:36 -0700 Subject: RE: VLF: 8969.99 Bob and Stefan, Any thought of using Fluorinert to prevent coil breakdown? In indoor applications, if we didn't want a high-voltage (including 100kV and higher) coil (or transformer or connector or circuit board) to arc (including during wide-temperature range testing), we would simply drop the whole device (including batteries, power supply and modulator, if that made things more convenient) into fluorinert, without any insulation, encapsulation or coating on the circuit boards, coil or other components. We re-used the fluorinert without complications, and after removing items from fluorinert did not need to clean the previously-immersed items in any way. High dielectric strength: >160kV/cm High resistivity: > 10^15 ohm-cm (1E15 ohm-cm) Inert Wide temperature range: -70C < T < 150C (various formulations available down to -100C and up to 215C) Thermal conductivity: 0.07 W/m*K (ROM similar to water) Color: colorless, clear (transparency ROM same as purified water) Toxicity: non-toxic for practical purposes, non-hazardous according to 3M. Experimental deep-water breathing fluid; inert; but as with all products observe safety data sheet (3M: ". not recommended for implantation in humans" ". Eye Contact: . flush, rinse"); the following lends a perspective: (3M) ".skin/eye irritation: no significant irritation"; "if swallowed: no need for first aid is anticipated". Downside: ~ $200 USD per gallon from manufacturer; but reclaimed fluorinert is available at lower prices. The evaporation rate is probably dependent on which formulation you select; I've heard some folks mention quick evaporation at > 100C temperatures, but I do not remember needing to add fluorinert during environmental temperature testing; a wide range of formulations with different boiling points is available. 73, Jim AA5BW From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Bob Raide Sent: Thursday, December 26, 2013 12:05 PM To: rsgb_lf_group@blacksheep.org Subject: RE: VLF: 8969.99 Stefan; I understand your setup. It is not that hard to move. I am not going to use such low VLF freq but as I mentioned am going for license to try get 28-30 kHz. Then I can run power up with less troubles of 8.9 kHz freq. It won't be till next season but am planning now for coil cover-coil size-etc. I have already 2' piece 18 inch white PVC pipe. Will wind 1000 meters #16 wire to start. I want to use my present 74 kHz coil inside as it is and add the extra coil outside then I can trim inside to hit exact resonance. _____ Date: Thu, 26 Dec 2013 19:44:09 +0100 From: Stefan.Schaefer@iup.uni-heidelberg.de To: rsgb_lf_group@blacksheep.org Subject: Re: VLF: 8969.99 Hi Bob, Oh, you're planning to become QRV on VLF, great! What inductance will you need for your system? What coil diameter and wire diameter will you use? It is important to calculate the dimension of that coil before you start to wind it. A diameter of at least 60cm is to be recommended, better 80cm. But of course it depends on the wire diameter and isolation (or insulation?). If you just use a coil body that is on hand and start winding, you may find the residual L is much to low and then you come out with 3 coils in series which will be a huge construction in very inefficient. You should also leave some distance to ground, to prevent losses into the soil. A distance equal to the coil diameter is fine. How will you manage the high voltages on the antenna? You will have to manage 50 kV rms or so. For me, the situation is not as easy. I must not leave the coil its position permanenty. I have to remove it after the experiment. But that's not so dramatic. I can leave it into the building and we have an elevator... Keep us informed by some photos :-) 73, Stefan/DK7FC Am 26.12.2013 18:58, schrieb Bob Raide: Stefan; If I go to VLF I am going to add to my existing inductance outside. I plan to make a box using "plexiglass" quarter inch thick with glued seams so is weather proof. It will be clear [no color] and is very good dielectric. I was going to ask you how much clearance I need and 30 cm is about 1 foot or 12 inches clearance around the coil. Leave air gap around bottom so air can circulate so you don't build up moisture. Small muffin fan with shroud to pull fresh air up and around coil and out. Could even use clear vinyl material .025 thick and a clear vinyl box over a plastic pipe frame would be cheaper. Clear vinyl used for side curtains on boats-etc. I am in sewing business [make boat and truck covers] so could make you cover and you build the frame-I ship clear vinyl cover UPS to you or you could have local canvas company make it. Use "RTV" over stitches to make water tight-Bob _____ Date: Thu, 26 Dec 2013 18:32:43 +0100 From: Stefan.Schaefer@iup.uni-heidelberg.de To: rsgb_lf_group@blacksheep.org Subject: Re: VLF: 8969.99 Hi Bob, Of course, if the coil is protected against rain, then it is no problem. But the coil is quite large and due to the high voltage, the housing should ideally have a distance of 30cm or more to the coil. So the housing must be quite large, even more. And that makes it dangerous because of wind blasts on the to of the building in 35m AGL... Anyway it would be nice and i also thought about using a simple foil across the coil, without additional distance. However on LF, there are partial discharges on the top of the coil which burns holes into the protecting foil. And the VLF winding is 2000m long. It is a lot of effort to repair it after a short cut between some turns due to arcing. So it is a high risk. I think i will make a test in the near future and see if 9 kHz partial discharges are as agressive as 137 kHz partial discharges :-) 73, Stefan/DK7FC Am 26.12.2013 16:32, schrieb Bob Raide: Stefan; Even if you have your coils in weather proof housing rain is no good to transmit on 9 kHz? Bob _____ Date: Thu, 26 Dec 2013 13:55:11 +0100 From: Stefan.Schaefer@iup.uni-heidelberg.de To: rsgb_lf_group@blacksheep.org Subject: Re: VLF: 8969.99 Hi Uwe, Tom, VLF, Best signal ever from Tom, capture attached. Is it due to the propagation or did it improve your signal? What about some tests in OPDS32 or maybe JT9-30? Unfortunately there is permanent rain here so i have to wait some days longer. 73, Stefan/DK7FC ------=_NextPart_000_0316_01CF0295.A004DE50 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Bob,

 

Thanks for the feedback, sounds like you have corona well-managed on = the coil.

 

For future reference, in case someone in the group has an outdoor HV = application in a particularly humid environment wherein operation = without maintenance is particularly desirable:

 

There are inexpensive lightweight encapsulation materials and = encapsulation methods that will allow long-term maintenance-free HV = outdoor operation in high humidity. The humidity resistance of most = high-humidity HV insulation materials degrades with time and temperature = cycling; a small subset of these hold up over time and temperature = cycling in humid environments; an even smaller subset is also = lightweight and inexpensive. Unfortunately this small subset of = inexpensive long-term robust outdoor high-humidity solutions is = difficult to repair or rework if such becomes necessary. This is why, = for low-cost lightweight outdoor HV equipment, we liked to develop = outdoor-application HV electronics in Fluorinert until turns ratios, = inductances, winding losses, spacings, coil form size/weight and other = factors were just right (with Flourinert one can make winding changes = and test in minutes), and then apply the long-term robust = encapsulant.

 

The above doesn’t matter for your application, since in your = application the issues are at the HV output end and beyond, and those = localized problem sites can be managed with spheres. Nor does it matter = for Stefan’s application, since Stephan’s coil does not = remain outdoors between tests. The above is useful for equipment that = remains outdoors in high humidity environments. For most low-cost = lightweight HV insulation materials, the humidity threshold of corona = inception declines over weeks and months of diurnal temperature cycling = in high humidity environments; the solutions impervious to this = degradation don’t accommodate quick rework, and Fluorinert makes = this rework easy until the bugs are out and optimization is complete, at = which time an inexpensive lightweight high-humidity outdoor HV = encapsulant with 10-year life can be applied.

 

Apologies for  the digression from your theme; I thought this = might come in handy for future generations of unattended/remote VLF = equipment, and thought I’d better write it down while it was in = mind.

 

Looking forward to your next step in LF!

 

73, Jim AA5BW    

 

From:= = owner-rsgb_lf_group@blacksheep.org = [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Bob = Raide
Sent: Thursday, December 26, 2013 4:12 PM
To: = rsgb_lf_group@blacksheep.org
Subject: RE: VLF: = 8969.99

 

Jim;
I see it's a liquid = that is really a coolant.  I use clear lacquer and corona = dope in a spray can and spray coils with it.  I use Stefan's = round brass balls that I have soldered to any point that shows = signs of corona  arcing.  It's at the high voltage end of the = coil that starts causing trouble  and from that point = onward. 
 Fluorinert would be great for an item = that had high voltages and large amounts of heat = present to submerge the item in = it-Bob
 

From: hvanesce@comcast.net
To: rsgb_lf_group@blacksheep.org=
Date: Thu, 26 Dec 2013 15:14:36 -0700
Subject: RE: VLF: = 8969.99

Bob and Stefan,

 

Any thought of using Fluorinert to prevent coil = breakdown?

 

In indoor applications, if we didn’t want a high-voltage = (including 100kV and higher) coil (or transformer or connector or = circuit board) to arc (including during wide-temperature range testing), = we would simply drop the whole device (including batteries, power supply = and modulator, if that made things more convenient) into fluorinert, = without any insulation, encapsulation or coating on the circuit boards, = coil or other components. We re-used the fluorinert without = complications, and after removing items from fluorinert did not need to = clean the previously-immersed items in any way.

 

High dielectric strength: >160kV/cm

High resistivity: > 10^15 ohm-cm  (1E15 ohm-cm)

Inert

Wide temperature range: -70C < T < 150C (various formulations = available down to -100C and up to 215C)

Thermal conductivity: 0.07 W/m*K (ROM similar to water)

Color: colorless, clear (transparency ROM same as purified = water)

Toxicity: non-toxic for practical purposes, non-hazardous according = to 3M. Experimental deep-water breathing fluid; inert; but as with all = products observe safety data sheet (3M: “… not recommended = for implantation in humans” “… Eye Contact: … = flush, rinse”); the following lends a perspective: (3M) = “…skin/eye irritation: no significant = irritation”;  “if swallowed: no need for first aid is = anticipated”.

 

Downside: ~ $200 USD per gallon from manufacturer; but reclaimed = fluorinert is available at lower prices.

The evaporation rate is probably dependent on which formulation you = select; I’ve heard some folks mention quick evaporation at > = 100C temperatures, but I do not remember needing to add fluorinert = during environmental temperature testing; a wide range of formulations = with different boiling points is available.

 

73, Jim AA5BW

 

 

<= div style=3D'border:none;border-top:solid windowtext 1.0pt;padding:3.0pt = 0in 0in 0in;border-color:currentColor currentColor'>

From:= = owner-rsgb_lf_group@bl= acksheep.org [mailto:owner-rsgb_lf_g= roup@blacksheep.org] On Behalf Of Bob Raide
Sent: = Thursday, December 26, 2013 12:05 PM
To: rsgb_lf_group@blacksheep.org=
Subject: RE: VLF: 8969.99

=

 

=

Stefan;
I understand = your setup.  It is not that hard to move.
I am not going to use = such low VLF freq but as I mentioned am going for license to try get = 28-30 kHz.  Then I can run power up with less troubles of 8.9 kHz = freq.  It won't be till next season but am planning now for coil = cover-coil size-etc.  I have already 2' piece 18 inch white PVC = pipe.  Will wind 1000 meters #16 wire to start.  I want to use = my present 74 kHz coil inside as it is and add the extra coil outside = then I can trim inside to hit exact resonance. =
 

Date: Thu, 26 Dec 2013 = 19:44:09 +0100
From: Stefan.Schaefer@iup= .uni-heidelberg.de
To: rsgb_lf_group@blacksheep.org=
Subject: Re: VLF: 8969.99

Hi Bob,

Oh, you're = planning to become QRV on VLF, great!
What inductance will you need = for your system? What coil diameter and wire diameter will you use? It = is important to calculate the dimension of that coil before you start to = wind it. A diameter of at least 60cm is to be recommended, better 80cm. = But of course it depends on the wire diameter and isolation (or = insulation?). If you just use a coil body that is on hand and start = winding, you may find the residual L is much to low and then you come = out with 3 coils in series which will be a huge construction in very = inefficient. You should also leave some distance to ground, to prevent = losses into the soil. A distance equal to the coil diameter is = fine.
How will you manage the high voltages on the antenna? You will = have to manage 50 kV rms or so.

For me, the situation is not as = easy. I must not leave the coil its position permanenty. I have to = remove it after the experiment. But that's not so dramatic. I can leave = it into the building and we have an elevator...
Keep us informed by = some photos :-)

73, Stefan/DK7FC


Am 26.12.2013 18:58, = schrieb Bob Raide:

Stefan;
If I go to = VLF I am going to add to my existing inductance outside.  I plan to = make a box using "plexiglass" quarter inch thick with glued = seams so is weather proof.  It will be clear [no color] and is very = good dielectric.  I was going to ask you how much clearance I need = and 30 cm is about 1 foot or 12 inches clearance around the = coil.  Leave air gap around bottom so air can circulate so you = don't build up moisture.  Small muffin fan with shroud to pull = fresh air up and around coil and out.
Could even use clear vinyl = material .025 thick and a clear vinyl box over a = plastic pipe frame would be cheaper.  Clear vinyl used for side = curtains on boats-etc.
I am in sewing business [make boat and truck = covers] so could make you cover and you build the frame-I ship clear = vinyl cover UPS to you or you could have local canvas company make = it.  Use "RTV" over stitches to make water = tight-Bob
 

Date: Thu, 26 Dec 2013 = 18:32:43 +0100
From: Stefan.Schaefer@iup= .uni-heidelberg.de
To: rsgb_lf_group@blacksheep.org=
Subject: Re: VLF: 8969.99

Hi Bob,

Of course, if = the coil is protected against rain, then it is no problem. But the coil = is quite large and due to the high voltage, the housing should ideally = have a distance of 30cm or more to the coil. So the housing must be = quite large, even more. And that makes it dangerous because of wind = blasts on the to of the building in 35m AGL...
Anyway it would be = nice and i also thought about using a simple foil across the coil, = without additional distance.
However on LF, there are partial = discharges on the top of the coil which burns holes into the protecting = foil. And the VLF winding is 2000m long. It is a lot of effort to repair = it after a short cut between some turns due to arcing. So it is a high = risk.
I think i will make a test in the near future and see if 9 kHz = partial discharges are as agressive as 137 kHz partial discharges = :-)
73, Stefan/DK7FC

Am 26.12.2013 16:32, schrieb Bob Raide: =

Stefan;
Even if you have = your coils in weather proof housing rain is no good to transmit on 9 = kHz? Bob
 

Date: Thu, 26 Dec 2013 = 13:55:11 +0100
From: Stefan.Schaefer@iup= .uni-heidelberg.de
To: rsgb_lf_group@blacksheep.org=
Subject: Re: VLF: 8969.99

Hi Uwe, Tom, VLF,

Best = signal ever from Tom, capture attached. Is it due to the propagation or = did it improve your signal?
What about some tests in OPDS32 or maybe = JT9-30? Unfortunately there is permanent rain here so i have to wait = some days longer.

73, = Stefan/DK7FC

------=_NextPart_000_0316_01CF0295.A004DE50--