Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id w7EIdYxs000319 for ; Tue, 14 Aug 2018 20:39:35 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1fpdzt-0006B9-P9 for rs_out_1@blacksheep.org; Tue, 14 Aug 2018 19:24:49 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1fpdzk-0006Ay-4D for rsgb_lf_group@blacksheep.org; Tue, 14 Aug 2018 19:24:40 +0100 Received: from resqmta-ch2-08v.sys.comcast.net ([2001:558:fe21:29:69:252:207:40]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.91_59-0488984) (envelope-from ) id 1fpdze-00043O-Vc for rsgb_lf_group@blacksheep.org; Tue, 14 Aug 2018 19:24:38 +0100 Received: from resomta-ch2-06v.sys.comcast.net ([69.252.207.102]) by resqmta-ch2-08v.sys.comcast.net with ESMTP id pdp9fEDoS6R28pdzXf01Vl; Tue, 14 Aug 2018 18:24:27 +0000 X-DKIM-Result: Domain=comcast.net Result=Signature OK DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net; s=q20161114; t=1534271067; bh=QaWRkUaVOcjmx+Sy3vAmD2wPY82X2rvxZqyfhA6nch8=; h=Received:Received:From:To:Subject:Date:Message-ID:MIME-Version: Content-Type; b=m4cXN+uCrucNK5d71dnwRAGZxv4cS9vQipIGrkAA31fMmCWIHrh04yHjFy8oqEIvG I98GTGvEBw1DNf3GLebFjBoDMpZavikhC/bot23tix8HN+AtoXbJsbZ69+GZXVlXa0 34RKd5cj7FMQn5yspixLsCUvkK5YkYf535qCyuyf74JooXM63fQX9SVgKKw1mZDAUo +DC6iAJTEm6pcAgPmthwhpcRBdjyeC5fp1HYMT3dgElXK+IldinurKzttkWzVOwGYm ZMnaJmMVc1/rRw76HeK7uWnG3eLdohzxXfAQdX9HtBQpSqPV9I+dB1tsxJVTqnyTaF cEupfYCUDam0w== Received: from Owner ([IPv6:2601:140:8500:7f9f:6153:527:68ab:c32d]) by resomta-ch2-06v.sys.comcast.net with ESMTPA id pdzUfovrazIWspdzUfOdBz; Tue, 14 Aug 2018 18:24:25 +0000 From: To: Date: Tue, 14 Aug 2018 14:23:43 -0400 Message-ID: <004b01d433fc$06d7d410$14877c30$@comcast.net> MIME-Version: 1.0 X-Mailer: Microsoft Outlook 14.0 Thread-Index: AdQz++veu3geeRZLRxmvqZmRTsaELw== Content-Language: en-us X-CMAE-Envelope: MS4wfPSr7x+htn3u0JrcVFLbHINfoAOldvQF5pcveYqCVf6yqo9zBYkKo1nzaqSyR2S6xNamkh/VrB7uPsvRvNqbQmhXs15kdYowt8B/KuHEhxg2czglbaOB OtBNHXZWRMmDyVsFz4wI7eehJpQpQp8Ef2ofMQRdBPpAGRG1Hbkm8oM2PObP3hM4lHl9l4v4uZIFeAAI5pNj+v6ZPpJ4GucRTWZZVaO0Ybr9SFEJsydR2QT/ X-Spam-Score: -0.7 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. 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Content preview: Hello Stefan, Some interesting LiFePO cycle-life information [including information related to energy throughput (total energy before end of life)], for batteries made by the SmartBattery company: Fairly detailed cycle-life specifications and capacity vs temperature specifications (and price), for a 2.4kWh battery: [...] Content analysis details: (-0.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [2001:558:fe21:29:69:252:207:40 listed in] [list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (hvanesce[at]comcast.net) -0.0 SPF_PASS SPF: sender matches SPF record -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 T_KAM_HTML_FONT_INVALID BODY: Test for Invalidly Named or Formatted Colors in HTML 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: f190dc8f4f83e88c974c8127ee718502 Subject: RE: LF: RE: Experimenting on 2470 Hz and 1970 Hz (some battery data) Content-Type: multipart/alternative; boundary="----=_NextPart_000_004C_01D433DA.7FC8A510" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.8 required=5.0 tests=HTML_40_50,HTML_MESSAGE, NO_REAL_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 This is a multipart message in MIME format. ------=_NextPart_000_004C_01D433DA.7FC8A510 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Hello Stefan, =20 Some interesting LiFePO cycle-life information [including information = related to energy throughput (total energy before end of life)], for = batteries made by the SmartBattery company: =20 Fairly detailed cycle-life specifications and capacity vs temperature = specifications (and price), for a 2.4kWh battery: https://www.lithiumion-batteries.com/products/12v-200ah-lithium-ion-batte= ry/ =20 Fairly detailed cycle-life specifications and capacity vs temperature = specifications (and price), for a 3.6kWh battery: https://www.lithiumion-batteries.com/products/12v-300ah-lithium-ion-batte= ry/ =20 Temperature: The capacity vs. temperature information in the two datasheets above = refers to a single discharge cycle; but in the absence of information on = energy throughput (total energy before end of life), the capacity = derating with temperature (in the two datasheets above) might also be = considered as a best-case (optimistic) derating factor for energy = throughput (total energy before end of life) vs. temperature.=20 =20 General cycle-life specifications for all SmartBattery LiFePO batteries: https://www.lithiumion-batteries.com/lithiumFAQ.php =20 Considering all of the above, it might not be unreasonable to expect = (with 80% discharges) 4000 times 3.6 kWh before the 3.6kWh battery = becomes a 1.8 kWh battery, if the battery is discharged at 1 hour to 3 = hour (to 80% discharge) rate, at temperatures above 50F. That would seem = to support years of local and remote tests. Storage life characteristics = of many types of lithium batteries can, under less than ideal storage = conditions (charged too quickly before storage, charged to more than 70% = before storage, stored at a less-desirable temperature, etc.) become the = limiting factor when years of use is planned; but LiFePO might have = significantly better (and more forgiving) storage characteristics than = many other types of lithium batteries; so perhaps 4000 deep (80%) cycles = from the above manufacturer is possible in realistic multi-year = scenarios. =20 =20 73, =20 Jim AA5BW =20 =20 =20 From: hvanesce@comcast.net [mailto:hvanesce@comcast.net]=20 Sent: Wednesday, August 8, 2018 12:52 PM To: 'rsgb_lf_group@blacksheep.org' Subject: RE: LF: RE: Experimenting on 2470 Hz and 1970 Hz =20 Hello Stefan, =20 Such a coincidence; I recently put a similar LiFePO battery on my wish = list. =20 I think that the ~ 3 kWh LiFePO batteries might last over 500 deep = cycles (some claims up to 2000 deep cycles) if charge/discharge = conditions (including temperature and rates) and battery specification = match reasonably. At 1000 deep cycles that might be ~ $1.50 per 3 kWh = cycle (less than the round-trip fuel cost driving to/from the test = location).=20 =20 I=E2=80=99m planning to obtain cycle-life data from a battery = custom-packaging company or battery-cell manufacturing company before = selecting an LiFePO battery and buying. They don=E2=80=99t like to = publish the data because they can=E2=80=99t guarantee it, but they have = a lot of data. Some lithium batteries can (practically speaking) provide = ~ 3 times as much energy throughput (total energy before end of life), = if they are used in a way that manufacturer/custom-packager cycle-life = data would suggest. I=E2=80=99m hoping that with such = manufacturer/packager data a 3 kWh battery can be specified, selected = and operated in a way that provides over 1000 deep cycles.=20 =20 For maximum energy throughput (total energy before end of life) from = lithium batteries I usually try to match (before selection/purchase, and = during use): (a) operating conditions and (b) = manufacturer/custom-packager battery-life data, for the following: Charge ambient temperature, discharge ambient temperature, charge rate, = discharge rate, discharge depth (DOD), and DOD during storage. I think that LiFePO might be more tolerant than some other lithium types = for some of the above parameters. Selection and operation to optimize for the 6 factors above can provide = 2x to 3x greater energy throughput (than with typical selection and use) = for many types of lithium batteries; hoping it helps for LiFePO. =20 =20 Sometimes with lithium batteries I also optimize for other parameters, = like: (a) max charge (not charging to 100%, based on = manufacturer/custom-packager life specifications) (b) charge profile (custom current-vs-time-and-voltage, using a custom = charger, based on manufacturer/custom-packager life specifications) These two can also significantly increase energy throughput, but they = require more effort for less benefit than the six factors in the = preceding paragraph, so I usually don=E2=80=99t bother with these last = two parameters. =20 Hope your power supply preparations go well. =20 I have a good power supply and amplifier for earth loop, and accessible = guard rails, and accessible good soil, but the accessible guard rails = are nowhere near the good soil :-(=20 =20 Your spectrograms look excellent. Suitable for framing for 2 kHz earth = loop far field; very nice images. =20 73, =20 Jim AA5BW =20 =20 =20 =20 =20 =20 =20 =20 From: owner-rsgb_lf_group@blacksheep.org = [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of DK7FC Sent: Tuesday, August 7, 2018 4:50 PM To: rsgb_lf_group@blacksheep.org Subject: Re: LF: RE: Experimenting on 2470 Hz and 1970 Hz =20 Hi Jim,=20 yes, i bet that 970 Hz will be possible without much trouble. Today i = continued with some next preparations: Some years ago i built a DC power = supply from '12 V' to 0...150 V. It is capable to manage 500W, at least = i think so :-) I made a short test at 180 W output power and = measured/calculated 84 % efficiency. Since i learned a bit more since = the time i constructed it, i think i can even rise the efficiency by = replacing a MOSFET... Also i consider to invest in the future and buy something like this: = https://www.robur-akku.de/ Quite expensive but others buy a 'FT897' or = 'TS-2000' or 'IC-756' or such stuff :-) The 48 V / 60 Ah version contains about 3 kWh so it would be no problem = to drive a 1 kW PA for 2 hours (or even 2 kW for 1 hour!) at a good = efficiency and without a loud, inefficient and stinking generator that = doesn't manage dynamic power changes...=20 The modern world! At least, the next idea is to build a H bridge running at 0...150V. It = should allow to manage the next 3 dB power step at least. And the = circuit design will be such that i can go down to ELF (the real ELF, = 3...30 Hz). A discrete tank circuit should prevent from harmonic = radiation. I will make measurements showing the signal in the frequency = domain then ;-) 73, Stefan Am 06.08.2018 20:40, schrieb hvanesce@comcast.net:=20 Stefan, =20 Congratulations on 2470 Hz and 1970 Hz (ULF) far-field records! =20 A remarkable step from inverted-L efforts below 3 KHz last year; high = SNR in 40 minutes at 2x far field on (if memory serves) the first = attempt after your trial run.=20 =20 Interesting that your 2470 Hz and 1970 Hz results were somewhat similar = in this variable-propagation region (2kHz-4kHz 100km-1000km). Could that = mean good things for lower frequencies? Perhaps most of your E-field is = vertically polarized with this loop; I wonder if that will provide more = stable propagation in this region. =20 Thanks for pushing the boundaries again. =20 73, =20 Jim AA5BW =20 =20 =20 =20 =20 From: owner-rsgb_lf_group@blacksheep.org = [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of DK7FC Sent: Monday, August 6, 2018 10:19 AM To: rsgb_lf_group@blacksheep.org Subject: ULF: Experimenting on 2470 Hz and 1970 Hz =20 Hi ULF,=20 On Sunday, 5th 2018 i successfully crossed the far field border on 2470 = Hz for the first time. That's the 121 km band. Later i even crossed it = on 1970 Hz, the 152 km band. These are two new records of the lowest = frequency signals generated by amateurs and received in the far field. = The distance between RX and TX was 55.6 km . The far field for 2470 Hz = starts at 19.4 km distance. For 1970 Hz it starts at 24.3 km distance. = The RX antenna and the TX antennas were loops! By running about 100 W (PA DC input) i managed to get 910 mA antenna = current on 2470 Hz into the earth loop in JN39WI. Here i transmitted a = plain carrier from 06:13...07:15 UTC.=20 Later i QSYed to 1970 Hz and here i got 910 mA as well. The 1970 Hz = transmission took place from 07:19...08:21 UTC. Despite beeing in the middle of a large forest there was good internet = connectivity and so i was able so watch my own grabber window showing = the band activity on 2470 Hz in a spectrogram of 424 uHz FFT bin width, = which is very wide for that frequency range! The spectrogram uses a Hann = window and the FFT window time is about 40 minutes, so it took some time = until a peak builts up. But already after 20 minutes i saw that = something happens! After 40 minutes the carrier transmission reached an = SNR of about 20 dB! It was a relatively quiet morning for early August. All the VLF stream data is stored into a ~ 12 day covering buffer so i = have the chance to optimise the filter settings and antenna mixing in a = postprocessing to achieve the best SNR from the system. For the 1970 Hz transmission there was no spectrogram available but = since i had internet access and a Linux notebook available, i processed = the VLF stream data (via SSH remote access to the storage PC) during the = transmission and followed the peak's SNR building up! It clearly looks like this antenna outperforms my large inverted L in 30 = m above the ground, at least into the ULF range! This opens up a new = room for experimentation on the way down to DC! :-) Now i need to get = rid of these output transformers since they will become problematic for = wide-band experimentation on ULF / SLF. Now, attached you can find two images showing spectrum peaks from the = two bands, out of the 55.6 km distance. The complete transmission time = is here integrated in one peak. Since the carrier S/N can also be = calculated from decoding a '*' message in EbNaut, i also show the = results for such calculation along with the whole postprocessing chain. Spectrograms will be produced as well, but this will take a few hours = here... 73, Stefan ------=_NextPart_000_004C_01D433DA.7FC8A510 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable

Hello Stefan,

 

Some interesting LiFePO cycle-life information [including information = related to energy throughput (total energy before end of life)], for batteries = made by the SmartBattery company:

 

Fairly detailed cycle-life specifications and capacity vs temperature = specifications (and price), for a 2.4kWh = battery:

https://www.lithiumion-batteries.com/products/12v-200ah-lith= ium-ion-battery/

 

Fairly detailed cycle-life specifications and capacity vs temperature = specifications (and price), for a 3.6kWh = battery:

https://www.lithiumion-batteries.com/products/12v-300ah-lith= ium-ion-battery/

 

Temperature:

The capacity vs. temperature information in the two datasheets above = refers to a single discharge cycle; but in the absence of information on = energy throughput (total energy before end of life), the capacity derating with = temperature (in the two datasheets above) might also be considered as a = best-case (optimistic) derating factor for energy throughput (total = energy before end of life) vs. temperature.

 

General cycle-life specifications for all SmartBattery LiFePO = batteries:

https://www.= lithiumion-batteries.com/lithiumFAQ.php

 

Considering all of the above, it might not be unreasonable to expect = (with 80% discharges) 4000 times 3.6 kWh before the 3.6kWh battery = becomes a 1.8 kWh battery, if the battery is discharged at 1 hour to 3 = hour (to 80% discharge) rate, at temperatures above 50F. That would seem = to support years of local and remote tests. Storage life characteristics = of many types of lithium batteries can, under less than ideal storage = conditions (charged too quickly before storage, charged to more than 70% = before storage, stored at a less-desirable temperature, etc.) become the = limiting factor when years of use is planned; but LiFePO might have = significantly better (and more forgiving) storage characteristics than = many other types of lithium batteries; so perhaps 4000 deep (80%) cycles = from the above manufacturer is possible in realistic multi-year = scenarios. =C2=A0

 

73,

 

Jim AA5BW

=C2=A0=C2=A0=C2=A0=C2=A0

 

 

From: hvanesce@comcast.net [mailto:hvanesce@comcast.net] =
Sent: Wednesday, August 8, 2018 12:52 PM
To: = 'rsgb_lf_group@blacksheep.org'
Subject: RE: LF: RE: = Experimenting on 2470 Hz and 1970 Hz

 

Hello Stefan,

 

Such a coincidence; I recently put a similar LiFePO battery on my = wish list.

 

I think that the ~ 3 kWh LiFePO batteries might last over 500 deep = cycles (some claims up to 2000 deep cycles) if charge/discharge = conditions (including temperature and rates) and battery specification = match reasonably. At 1000 deep cycles that might be ~ $1.50 per 3 kWh = cycle (less than the round-trip fuel cost driving to/from the test = location).

 

I=E2=80=99m planning to obtain cycle-life data from a battery = custom-packaging company or battery-cell manufacturing company before = selecting an LiFePO battery and buying. They don=E2=80=99t like to = publish the data because they can=E2=80=99t guarantee it, but they have = a lot of data. Some lithium batteries can (practically speaking) provide = ~ 3 times as much energy throughput (total energy before end of life), = if they are used in a way that manufacturer/custom-packager cycle-life = data would suggest. I=E2=80=99m hoping that with such = manufacturer/packager data a 3 kWh battery can be specified, selected = and operated in a way that provides over 1000 deep cycles. =

 

For maximum energy throughput (total energy before end of life) from = lithium batteries I usually try to match (before selection/purchase, and = during use): (a) operating conditions and (b) = manufacturer/custom-packager battery-life data, for the = following:

Charge ambient temperature, discharge ambient temperature, charge = rate, discharge rate, discharge depth (DOD), and DOD during = storage.

I think that LiFePO might be more tolerant than some other lithium = types for some of the above parameters.

Selection and operation to optimize for the 6 factors above can = provide 2x to 3x greater energy throughput (than with typical selection = and use) for many types of lithium batteries; hoping it helps for = LiFePO.  

 

Sometimes with lithium batteries I also optimize for other = parameters, like:

(a) max charge (not charging to 100%, based on = manufacturer/custom-packager life = specifications)

(b) charge profile (custom current-vs-time-and-voltage, using a = custom charger, based on manufacturer/custom-packager life = specifications)

These two can also significantly increase energy throughput, but they = require more effort for less benefit than the six factors in the = preceding paragraph, so I usually don=E2=80=99t bother with these last = two parameters.

 

Hope your power supply preparations go well.

 

I have a good power supply and amplifier for earth loop, and = accessible guard rails, and accessible good soil, but the accessible = guard rails are nowhere near the good soil :-(

 

Your spectrograms look excellent. Suitable for framing for 2 kHz = earth loop far field; very nice images.

 

73,

 

Jim AA5BW

 

 

 

 

 

 

    

 

From: owner-rsgb_lf_group@bl= acksheep.org [mailto:owner-rsgb_lf_g= roup@blacksheep.org] On Behalf Of DK7FC
Sent: = Tuesday, August 7, 2018 4:50 PM
To: rsgb_lf_group@blacksheep.org=
Subject: Re: LF: RE: Experimenting on 2470 Hz and 1970 = Hz

 

Hi Jim, =

yes, i bet that 970 Hz will be possible without much trouble. = Today i continued with some next preparations: Some years ago i built a = DC power supply from '12 V' to 0...150 V. It is capable to manage 500W, = at least i think so :-) I made a short test at 180 W output power and = measured/calculated 84 % efficiency. Since i learned a bit more since = the time i constructed it, i think i can even rise the efficiency by = replacing a MOSFET...

Also i consider to invest in the future and = buy something like this: https://www.robur-akku.de/ Quite = expensive but others buy a 'FT897' or 'TS-2000' or 'IC-756' or such = stuff :-)
The 48 V / 60 Ah version contains about 3 kWh so it would = be no problem to drive a 1 kW PA for 2 hours (or even 2 kW for 1 hour!) = at a good efficiency and without a loud, inefficient and stinking = generator that doesn't manage dynamic power changes...
The modern = world!

At least, the next idea is to build a H bridge running at = 0...150V. It should allow to manage the next 3 dB power step at least. = And the circuit design will be such that i can go down to ELF (the real = ELF, 3...30 Hz). A discrete tank circuit should prevent from harmonic = radiation. I will make measurements showing the signal in the frequency = domain then ;-)

73, Stefan


Am 06.08.2018 20:40, = schrieb hvanesce@comcast.net: =

Stefan,

 

Congratulations on 2470 Hz and 1970 Hz (ULF) far-field = records!

 

A remarkable step from inverted-L efforts below 3 KHz last year; high = SNR in 40 minutes at 2x far field on (if memory serves) the first = attempt after your trial run.

 

Interesting that your 2470 Hz and 1970 Hz results were somewhat = similar in this variable-propagation region (2kHz-4kHz 100km-1000km). = Could that mean good things for lower frequencies? Perhaps most of your = E-field is vertically polarized with this loop; I wonder if that will = provide more stable propagation in this region.

 

Thanks for pushing the boundaries again.

 

73,

 

Jim AA5BW

 

 

 

  

 

From: owner-rsgb_lf_group@bl= acksheep.org [mailto:owner-rsgb_lf_g= roup@blacksheep.org] On Behalf Of DK7FC
Sent: = Monday, August 6, 2018 10:19 AM
To: rsgb_lf_group@blacksheep.org=
Subject: ULF: Experimenting on 2470 Hz and 1970 = Hz

 

Hi ULF, =

On Sunday, 5th 2018 i successfully crossed the far field border = on 2470 Hz for the first time. That's the 121 km band. = Later i even crossed it on 1970 Hz, the 152 km band. These = are two new records of the lowest frequency signals generated by = amateurs and received in the far field. The distance between RX and TX = was 55.6 km . The far field for 2470 Hz starts at 19.4 km distance. For = 1970 Hz it starts at 24.3 km distance. The RX antenna and the TX = antennas were loops!

By running about 100 W (PA DC input) i = managed to get 910 mA antenna current on 2470 Hz into the earth loop in = JN39WI. Here i transmitted a plain carrier from 06:13...07:15 UTC. =
Later i QSYed to 1970 Hz and here i got 910 mA as well. The 1970 Hz = transmission took place from 07:19...08:21 UTC.

Despite beeing in = the middle of a large forest there was good internet connectivity and so = i was able so watch my own grabber window showing the band activity on = 2470 Hz in a spectrogram of 424 uHz FFT bin width, which is very wide = for that frequency range! The spectrogram uses a Hann window and the FFT = window time is about 40 minutes, so it took some time until a peak = builts up. But already after 20 minutes i saw that something happens! = After 40 minutes the carrier transmission reached an SNR of about 20 dB! = It was a relatively quiet morning for early August.
All the VLF = stream data is stored into a ~ 12 day covering buffer so i have the = chance to optimise the filter settings and antenna mixing in a = postprocessing to achieve the best SNR from the system.

For the = 1970 Hz transmission there was no spectrogram available but since i had = internet access and a Linux notebook available, i processed the VLF = stream data (via SSH remote access to the storage PC) during the = transmission and followed the peak's SNR building up!

It clearly = looks like this antenna outperforms my large inverted L in 30 m above = the ground, at least into the ULF range! This opens up a new room for = experimentation on the way down to DC! :-) Now i need to get rid of = these output transformers since they will become problematic for = wide-band experimentation on ULF / SLF.

Now, attached you can = find two images showing spectrum peaks from the two bands, out of the = 55.6 km distance. The complete transmission time is here integrated in = one peak. Since the carrier S/N can also be calculated from decoding a = '*' message in EbNaut, i also show the results for such calculation = along with the whole postprocessing chain.

Spectrograms will be = produced as well, but this will take a few hours here...

73, = Stefan

------=_NextPart_000_004C_01D433DA.7FC8A510--