<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
<font face="Arial">And, if you're going to 'play' with chokes, etc,
a good, relatively inexpensive VNA like the DG8SAQ VNWA3, which,
with careful setup and calibration can accurately measure high
impedances to 10Kohms at 30MHz. I have been able to duplicate
K9YC's measurements with my VNWA3. <br>
<br>
Kurt Poulsen OZ7OU has an excellent application note on high
impedance measurement with the VNWA3. The nanoVNA, at under $100,
has reasonable accuracy to about 1K ohm (which I believe is
limited by the return loss S/N ratio) but requires careful
calibration with setting of the "measurement plane" for the device
under test .... and, probably, shielding of the test fixture.<br>
<br>
I have not been able to find the original article "how to measure
very high impedances" by Poulsen in a Google search, in which he
discusses K9YC's measurements but I will forward a copy (9.2MB) to
anyone who would like to have it.<br>
<br>
73,<br>
Jules-K2KGJ<br>
<br>
</font><br>
<div class="moz-cite-prefix">On 7/28/2021 10:09 PM,
<a class="moz-txt-link-abbreviated" href="mailto:tangerinesdr-request@lists.tapr.org">tangerinesdr-request@lists.tapr.org</a> wrote:<br>
</div>
<blockquote type="cite"
cite="mid:mailman.443.1627524579.890.tangerinesdr_lists.tapr.org@lists.tapr.org">
<pre class="moz-quote-pre" wrap="">Send TangerineSDR mailing list submissions to
<a class="moz-txt-link-abbreviated" href="mailto:tangerinesdr@lists.tapr.org">tangerinesdr@lists.tapr.org</a>
To subscribe or unsubscribe via the World Wide Web, visit
<a class="moz-txt-link-freetext" href="http://lists.tapr.org/mailman/listinfo/tangerinesdr_lists.tapr.org">http://lists.tapr.org/mailman/listinfo/tangerinesdr_lists.tapr.org</a>
or, via email, send a message with subject or body 'help' to
<a class="moz-txt-link-abbreviated" href="mailto:tangerinesdr-request@lists.tapr.org">tangerinesdr-request@lists.tapr.org</a>
You can reach the person managing the list at
<a class="moz-txt-link-abbreviated" href="mailto:tangerinesdr-owner@lists.tapr.org">tangerinesdr-owner@lists.tapr.org</a>
When replying, please edit your Subject line so it is more specific
than "Re: Contents of TangerineSDR digest..."
Today's Topics:
1. Re: [HamSCI] RE: Notes from PSWS / TangerineSDR call of
07-26-2021 (Ward Silver)
----------------------------------------------------------------------
Message: 1
Date: Wed, 28 Jul 2021 21:08:41 -0500
From: Ward Silver <a class="moz-txt-link-rfc2396E" href="mailto:hwardsil@gmail.com"><hwardsil@gmail.com></a>
To: TAPR TangerineSDR Modular Software Defined Radio
<a class="moz-txt-link-rfc2396E" href="mailto:tangerinesdr@lists.tapr.org"><tangerinesdr@lists.tapr.org></a>
Subject: Re: [TangerineSDR] [HamSCI] RE: Notes from PSWS /
TangerineSDR call of 07-26-2021
Message-ID:
<a class="moz-txt-link-rfc2396E" href="mailto:CAFr7d=qkP1Dh6nBnqfQDOu5LaZGbS7No7uERsdUrzptxXo+Sjw@mail.gmail.com"><CAFr7d=qkP1Dh6nBnqfQDOu5LaZGbS7No7uERsdUrzptxXo+Sjw@mail.gmail.com></a>
Content-Type: text/plain; charset="utf-8"
Recent editions of the Handbook offer several polarity protection circuits
in the Power Sources chapter (Chapter 7). Some of them use P-channel
MOSFETS that have much lower forward voltage drops than standard diodes,
even Schottky barrier diodes.
Regarding common-mode chokes, I think it is better to determine the need
first - what frequency range and amplitude, for example - and then select a
type of choke to do the job. For example, blocking RF common-mode at VLF,
HF, and VHF/UHF requires different ferrite mixes and the number of turns
also makes a difference in the choke's peak rejection range. (See Chapter 5
- RF Techniques - of recent Handbook editions. Much of this was written by
K9YC and comes from his tutorials.)
I realize the original post was about power supply failures and not RFI but
nothing like a good digression :-) Analog Devices also just published a
couple of articles about protecting inputs for low-power interfaces in the
Analog Dialogue - a little Googling will find the recent issues which are
free and public. All good stuff.
73, Ward N0AX
On Wed, Jul 28, 2021 at 7:54 PM <a class="moz-txt-link-rfc2396E" href="mailto:tangerinesdr-request@lists.tapr.org"><tangerinesdr-request@lists.tapr.org></a> wrote:
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">
Jonathan,
You can use a standard silicon diode like the 1N4000 series (1A rating)
for the polarity protection diode unless you want to clamp the reverse
voltage at less than 0.7-0.8 volts, in which case a Schottky will
provide a lower clamping voltage.? Since the reverse protection diode
will clamp reverse transients, you don't need a bidirectional TVS.
Jules
On 7/28/2021 3:16 PM, Jonathan wrote:
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">Phil,
This design (Integrated VLF antenna/preamp in PVC pipe with Raspberry
Pi box) was used for an MIT study and the author of vlfrx-tools built
a bunch of these antennas and boxes for those conducting the study.
This was in 2018. Since this might have fallen under your umbrella,
did you hear of it or know who the PI might be? The DC-DC converter
has an operating frequency of 100-600 kHz, so it doesn?t really affect
anything below that. Paul really liked the performance of his design.
He even wrote a guide on how to set up the Radpberry Pi as a VLF SDR
using his vlfrx-tools software.
Jules,
I really appreciate the supplied schematic. Should I use the Schottky
diode where you drew the regular diode, in parallel like you said? I
could also probably solder the MLCC across the leads of the
electrolytic and install it. Also, that TVS is bidirectional. Should a
unidirectional TVS be used so it clips any negative spikes closer to 0V?
David,
Tom mentioned the same. I?ll be working on trying to fit an
electrolytic and a ceramic capacitor.
Khan,
This is good news. Email me if you have issues.
Jonathan
KC3EEY
On Jul 28, 2021, at 2:27 PM, Julius Madey <<a class="moz-txt-link-abbreviated" href="mailto:hillfox@fairpoint.net">hillfox@fairpoint.net</a>
<a class="moz-txt-link-rfc2396E" href="mailto:hillfox@fairpoint.net"><mailto:hillfox@fairpoint.net></a>> wrote:
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">Jonathan,
I still think you need to get rid of the series polarity protection
diode and suggest the following schematic (with 22uf 50 volt Aluminum
electrolytic)
<eaeficdplljflikc.png>
The PTC poly fuse will open either on overload, sustained voltage
above TVS rating or reverse polarity.? This will also snub transients
on the line the series diode may have permitted.? There might be some
virtue in adding an MLCC cap of ~ 0.47uf in parallel with the
electrolytic for lower overall ESR.
Regards,
Jules-K2KGJ
On 7/28/2021 12:41 PM, Jonathan wrote:
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">Hi Tom,
That makes a lot of sense. I?ll try fit a 0.1uF and a 22-47uF
electrolytic on the feedline loop.
Thanks again!
Jonathan
KC3EEY
On Jul 28, 2021, at 10:55 AM, Tom McDermott <<a class="moz-txt-link-abbreviated" href="mailto:tom.n5eg@gmail.com">tom.n5eg@gmail.com</a>
<a class="moz-txt-link-rfc2396E" href="mailto:tom.n5eg@gmail.com"><mailto:tom.n5eg@gmail.com></a>> wrote:
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">Hi Jonathan - a concern is that the DC-DC converter input stage
would become unstable and oscillate
with the cable inductance.? If that happens then there could be
high frequency AC voltages present at the
input of the converter.? Would those over-voltage the input??
Possibly.?? Would it radiate RFI from the cable?? Likely.
Good design dictates sufficiently low source impedance to the DC-DC
converter.? Almost all linear regulators
require it.? An electrolytic and ceramic bypass pair right at the
DC-DC input would be considered good design by many.
-- Tom, N5EG
On Wed, Jul 28, 2021 at 7:30 AM Jonathan <<a class="moz-txt-link-abbreviated" href="mailto:emuman100@gmail.com">emuman100@gmail.com</a>
<a class="moz-txt-link-rfc2396E" href="mailto:emuman100@gmail.com"><mailto:emuman100@gmail.com></a>> wrote:
John,
Thanks for the suggestion! I think I?ll start with the
overvoltage age spike of 50V for 100ms or less based on the
datasheet spec of the DC-DC converter. I was thinking of some
sort of fusable circuit protection now that I?ll be using a TVS
diode to mitigate stress from the follow current.
Tom,
The datasheet wasn?t clear on the need for input filtering. On
the output of both the IP2415S, I have 0.1uF ceramic
capacitors. In the datasheet, it only mentions a spec of ?Input
Reflected Rated Current? with a series inductor and shunt
capacitor. I don?t really understand exactly what this is, but
it lists ?20mAp-p through a 12uH inductor and 47uF capacitor?.
Nothing else is mentioned about input protection or filtering.
In both situations that the DC-DC failed, the cable length was
only 4? of cat 5. This circuit that was proved and tested by
Paul, including the receiver and schematic I attached, did not
have such an issue, but the only difference is that the voltage
was lower than 30V. That?s why I was thinking it was a
turn-on/off spike. I think that in a lot of typical
applications, the input voltage isn?t that high, so spikes
don?t normally present a problem. The DC-DC that feeds the
receiver DC-DC has never failed and it was always fed with 18V
or less.
Jules,
You recommend the Schottky diode in parallel with the TVS, then
a series PTC, so during a spike, the TVS will conduct and the
PTC would fuse, and during a reverse polarity condition, the
Schottky diode will conduct with limited current due to the PTC
fusing? I can see the benefit that the series PTC in normal a
normal circuit condition would drop much less voltage that the
Schottky diode.
All in all, I agree with adding some capacitance to filter
voltage spikes and reduce or eliminate them. I?ll need to be
sure not to exceed the DC-DC max load capacitance, which is
47uF in this case.
But, to me, the most plausible cause for the failures are turn
on/off voltage spikes, even with a short length of cable.
Adding electrolytics is a bit difficult due to the tight space
constraint as seen in my previous email, so I?ll try out the
TVS and a PTC. Other than voltage spikes, does anything else
come to mind?
Thanks guys.
Jonathan
KC3EEY
On Tue, Jul 27, 2021 at 9:34 AM Jonathan <<a class="moz-txt-link-abbreviated" href="mailto:emuman100@gmail.com">emuman100@gmail.com</a>
<a class="moz-txt-link-rfc2396E" href="mailto:emuman100@gmail.com"><mailto:emuman100@gmail.com></a>> wrote:
Hi Everyone,
Before the meeting ended last night, I wanted to discuss
the issues I?ve experienced with my VLF active antenna. As
I mentioned, the DC-DC converter (XP Power IP2415S) failed
after I applied power. I turned the volume up because I
wasn?t hearing sferics, and shortly after, I heard the
squeal of the DC-DC converter. When I pulled out the
smaller foam core partially, I heard a squeal coming from
the DC-DC converter itself.
<image3.jpeg>
I had a failure of the DC-DC converter when I first built
the VLF preamp. It was being powered by the Raspberry Pi
box (same power circuit as my text box). I had a power
failure and when the power was restored, the DC-DC
converter failed.? In both situations, it was being
supplied with 30VDC, with the limit is 36V. The reason for
using 30V is to overcome the voltage drop from long cable
lengths.
After both failures, there was a low impedance across the
input of the DC-DC converter causing the supply to be
pulled down. Because the input and output are isolated, I
figured the fault had to have been caused by a voltage
spike on the input due to power being turned on and off.
The datasheet mentions that it can withstand 50V spikes at
100ms, but I can?t think of anything else that could cause
the DC-DC to fail, especially that 30V is used to power it
and any voltage spike would ride on top of that 30V. I
contacted XP Power about the issue.
Here is the schematic of the power path. The blocks are the
IP2415S DC-DC converter.
<image1.jpeg>
I?m powering the DC-DC converter with 30V from another
DC-DC converter in the test box and Raspberry Pi box
(Raspberry Pi box not shown, but same circuit). Keep in
mind, the length is still relatively short in my testing,
so cable inductance isn?t the primary reason for the spike.
Plus, at long lengths, the voltage would be much lower due
to voltage drop across the length, and I think this was why
Paul might not have seen this issue when he originally
tried and built this design.
To mitigate this problem with the supply voltage at 30V, I
decided to use a TVS diode across the input of the DC-DC
converter. Here is the schematic: (my apologies for the TVS
diode being backwards)
<image2.jpeg>
I chose a unidirectional TVS so there is also protection if
the voltage spikes have any negative components. I picked a
TVS with a working voltage of 33V, a Littel Fuse P4KE39A.
According to the datasheet, it looks like this would be
adequate. TVS diodes have a PN junction that is more
rugged, with a larger surface area for greater current
density. One thing I overlooked with this type of circuit
protection is that once the TVS conducts, current from the
power supply will be shunted too, known as the follow
current, and in some situations, this may cause issues
requiring a fuse. In this case, since the spikes are
probably short duration, and since the DC-DC converter in
the text/Pi box has short circuit protection, this should
not be an issue.
So the questions I have are: do you also think it could be
voltage spikes that caused the failures, and if so, was my
choice of TVS diode adequate. Also, one important question,
if I connect the anode of the TVS diode to the receiver
side ground, will I lose isolation? I know that during
spike current conduction, I will. I?m sure I can still get
adequate protection with the TVS diode anode connected to
the negative of the isolated power loop too, but I just
wanted to be sure.
Lastly, since the magnetometer board will undergo another
revision, I feel it may be worth it to add some sort or
adjustable regulator or use of an external power source
(not connected to the 5V pin of the Pi header) because even
with paralleling wires or pairs, some installations will
require very long lengths (especially since
interference-free locations are often far away from the
shack) and the voltage may drop to where the LDO cant
regulate. Using a higher voltage at the Pi end (like I do
with the VLF preamp) may be required for some
installations. I think this should be considered if it
already wasn?t addressed.
Jonathan
KC3EEY
On Jul 27, 2021, at 7:21 AM, Dr. Nathaniel A. Frissell
Ph.D. <<a class="moz-txt-link-abbreviated" href="mailto:nathaniel.frissell@scranton.edu">nathaniel.frissell@scranton.edu</a>
<a class="moz-txt-link-rfc2396E" href="mailto:nathaniel.frissell@scranton.edu"><mailto:nathaniel.frissell@scranton.edu></a>> wrote:
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">
Thank you, Tom.
The recording will be available later today at
<a class="moz-txt-link-freetext" href="https://youtu.be/AammohuygMw">https://youtu.be/AammohuygMw</a>
<a class="moz-txt-link-rfc2396E" href="https://youtu.be/AammohuygMw"><https://youtu.be/AammohuygMw></a> and hamsci.org/telecons
<a class="moz-txt-link-rfc2396E" href="http://hamsci.org/telecons"><http://hamsci.org/telecons></a>.
73 de Nathaniel W2NAF
*From:* TangerineSDR <<a class="moz-txt-link-abbreviated" href="mailto:tangerinesdr-bounces@lists.tapr.org">tangerinesdr-bounces@lists.tapr.org</a>
<a class="moz-txt-link-rfc2396E" href="mailto:tangerinesdr-bounces@lists.tapr.org"><mailto:tangerinesdr-bounces@lists.tapr.org></a>>
*On Behalf Of *Tom McDermott via TangerineSDR
*Sent:* Monday, July 26, 2021 10:02 PM
*To:* TAPR TangerineSDR Modular Software Defined Radio
<<a class="moz-txt-link-abbreviated" href="mailto:tangerinesdr@lists.tapr.org">tangerinesdr@lists.tapr.org</a>
<a class="moz-txt-link-rfc2396E" href="mailto:tangerinesdr@lists.tapr.org"><mailto:tangerinesdr@lists.tapr.org></a>>
*Cc:* Tom McDermott <<a class="moz-txt-link-abbreviated" href="mailto:tom.n5eg@gmail.com">tom.n5eg@gmail.com</a>
<a class="moz-txt-link-rfc2396E" href="mailto:tom.n5eg@gmail.com"><mailto:tom.n5eg@gmail.com></a>>
*Subject:* [TangerineSDR] Notes from PSWS / TangerineSDR
call of 07-26-2021
Notes from PSWS / TangerineSDR call of 07-26-2021
1. Bill is using chart.js for magnetometer charting. He is
setting up a database using Django web and database
framework for Python.
2. Scotty is looking at the Intel (Altera) Arria 10 GX
FPGA 10GX270 for the version 2 Data Engine (supporting
10GE). These FPGAs appear to be more available than the
MAX10 FPGAs. The intention is to develop DE Ver 1 and DE
Ver 2 in parallel
while awaiting FPGA component availability. The 10 GX
development boards are pretty expensive.
-- Tom, N5EG
--
Please follow the HamSCI Community Participation
Guidelines at
<a class="moz-txt-link-freetext" href="http://hamsci.org/hamsci-community-participation-guidelines">http://hamsci.org/hamsci-community-participation-guidelines</a>
<<a class="moz-txt-link-freetext" href="http://hamsci.org/hamsci-community-participation-guidelines">http://hamsci.org/hamsci-community-participation-guidelines</a>
</pre>
</blockquote>
</blockquote>
</blockquote>
</blockquote>
<pre class="moz-quote-pre" wrap="">.
</pre>
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">
---
You received this message because you are subscribed to
the Google Groups "HamSCI" group.
To unsubscribe from this group and stop receiving emails
from it, send an email to
<a class="moz-txt-link-abbreviated" href="mailto:hamsci+unsubscribe@googlegroups.com">hamsci+unsubscribe@googlegroups.com</a>
<a class="moz-txt-link-rfc2396E" href="mailto:hamsci+unsubscribe@googlegroups.com"><mailto:hamsci+unsubscribe@googlegroups.com></a>.
To view this discussion on the web visit
</pre>
</blockquote>
</blockquote>
</blockquote>
</blockquote>
</blockquote>
<pre class="moz-quote-pre" wrap=""><a class="moz-txt-link-freetext" href="https://groups.google.com/d/msgid/hamsci/SA0PR03MB5547CBF733EFEB4D829E659FF2E99%40SA0PR03MB5547.namprd03.prod.outlook.com">https://groups.google.com/d/msgid/hamsci/SA0PR03MB5547CBF733EFEB4D829E659FF2E99%40SA0PR03MB5547.namprd03.prod.outlook.com</a>
</pre>
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite">
<pre class="moz-quote-pre" wrap=""> <
</pre>
</blockquote>
</blockquote>
</blockquote>
</blockquote>
</blockquote>
<pre class="moz-quote-pre" wrap=""><a class="moz-txt-link-freetext" href="https://groups.google.com/d/msgid/hamsci/SA0PR03MB5547CBF733EFEB4D829E659FF2E99%40SA0PR03MB5547.namprd03.prod.outlook.com?utm_medium=email&utm_source=footer">https://groups.google.com/d/msgid/hamsci/SA0PR03MB5547CBF733EFEB4D829E659FF2E99%40SA0PR03MB5547.namprd03.prod.outlook.com?utm_medium=email&utm_source=footer</a>
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">.
</pre>
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">
</pre>
</blockquote>
</blockquote>
<pre class="moz-quote-pre" wrap="">--
Please follow the HamSCI Community Participation Guidelines at
<a class="moz-txt-link-freetext" href="http://hamsci.org/hamsci-community-participation-guidelines">http://hamsci.org/hamsci-community-participation-guidelines</a>
<a class="moz-txt-link-rfc2396E" href="http://hamsci.org/hamsci-community-participation-guidelines"><http://hamsci.org/hamsci-community-participation-guidelines></a>.
---
You received this message because you are subscribed to the Google
Groups "HamSCI" group.
To unsubscribe from this group and stop receiving emails from it,
send an email to <a class="moz-txt-link-abbreviated" href="mailto:hamsci+unsubscribe@googlegroups.com">hamsci+unsubscribe@googlegroups.com</a>
<a class="moz-txt-link-rfc2396E" href="mailto:hamsci+unsubscribe@googlegroups.com"><mailto:hamsci+unsubscribe@googlegroups.com></a>.
To view this discussion on the web visit
</pre>
</blockquote>
</blockquote>
</blockquote>
<pre class="moz-quote-pre" wrap=""><a class="moz-txt-link-freetext" href="https://groups.google.com/d/msgid/hamsci/59FAEE9C-11F5-4CDF-B960-2E583E42E89C%40gmail.com">https://groups.google.com/d/msgid/hamsci/59FAEE9C-11F5-4CDF-B960-2E583E42E89C%40gmail.com</a>
</pre>
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite">
<pre class="moz-quote-pre" wrap=""><
</pre>
</blockquote>
</blockquote>
</blockquote>
<pre class="moz-quote-pre" wrap=""><a class="moz-txt-link-freetext" href="https://groups.google.com/d/msgid/hamsci/59FAEE9C-11F5-4CDF-B960-2E583E42E89C%40gmail.com?utm_medium=email&utm_source=footer">https://groups.google.com/d/msgid/hamsci/59FAEE9C-11F5-4CDF-B960-2E583E42E89C%40gmail.com?utm_medium=email&utm_source=footer</a>
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">.
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">
</pre>
</blockquote>
</blockquote>
<pre class="moz-quote-pre" wrap="">
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <
<a class="moz-txt-link-freetext" href="http://lists.tapr.org/pipermail/tangerinesdr_lists.tapr.org/attachments/20210728/ad3fc26c/attachment.html">http://lists.tapr.org/pipermail/tangerinesdr_lists.tapr.org/attachments/20210728/ad3fc26c/attachment.html</a>
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">
------------------------------
Subject: Digest Footer
TangerineSDR mailing list
<a class="moz-txt-link-abbreviated" href="mailto:TangerineSDR@lists.tapr.org">TangerineSDR@lists.tapr.org</a>
<a class="moz-txt-link-freetext" href="http://lists.tapr.org/mailman/listinfo/tangerinesdr_lists.tapr.org">http://lists.tapr.org/mailman/listinfo/tangerinesdr_lists.tapr.org</a>
------------------------------
End of TangerineSDR Digest, Vol 28, Issue 21
********************************************
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">
<a class="moz-txt-link-rfc2396E" href="https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon"><https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon></a>
Virus-free.
<a class="moz-txt-link-abbreviated" href="http://www.avast.com">www.avast.com</a>
<a class="moz-txt-link-rfc2396E" href="https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link"><https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link></a>
<#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <a class="moz-txt-link-rfc2396E" href="http://lists.tapr.org/pipermail/tangerinesdr_lists.tapr.org/attachments/20210728/40ca27ad/attachment.html"><http://lists.tapr.org/pipermail/tangerinesdr_lists.tapr.org/attachments/20210728/40ca27ad/attachment.html></a>
------------------------------
Subject: Digest Footer
TangerineSDR mailing list
<a class="moz-txt-link-abbreviated" href="mailto:TangerineSDR@lists.tapr.org">TangerineSDR@lists.tapr.org</a>
<a class="moz-txt-link-freetext" href="http://lists.tapr.org/mailman/listinfo/tangerinesdr_lists.tapr.org">http://lists.tapr.org/mailman/listinfo/tangerinesdr_lists.tapr.org</a>
------------------------------
End of TangerineSDR Digest, Vol 28, Issue 31
********************************************
</pre>
</blockquote>
<br>
</body>
</html>