<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
<p>Thanks Jim,<br>
The antenna that came with the LoRa unit appears to be one of the
stubby plastic ones as seen at 10:43 in the video
<a class="moz-txt-link-freetext" href="https://www.youtube.com/watch?v=CJNq2I_PDHQ">https://www.youtube.com/watch?v=CJNq2I_PDHQ</a> (as opposed to the
one shown at 10:58 that came with version 1 of the Heltec module -
the PCBs I am using for the project have V2 printed on them)</p>
<p>Either way, as Andreas outlines video that antennas being
manufactured oversees and offered at a discounted price may not be
tuned to the stated frequency - which is why I am hesitant to use
what has been provided without some form of verification.<br>
</p>
<p>Thanks for the info - I will do some research on what is
available via amazon</p>
<p>Dave.<br>
</p>
<div class="moz-cite-prefix">On 2022-04-14 12:33 p.m., James Briante
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAPNOJziLg95H0oqmLpm4BkHicw0VZn7KVnWfrr=tp_dv4n=A7A@mail.gmail.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<div dir="ltr">
<div class="gmail_default" style="font-size:small">Hi Dave,</div>
<div class="gmail_default" style="font-size:small"><br>
</div>
<div class="gmail_default" style="font-size:small">Reflected
power (that can cause damage) occurs when the antenna
resonant frequency does not match the frequency of the
transmitting unit. HAM radio operates on many different bands,
so is the custom to place an antenna tuner between the Antenna
and the transmitter to match the impedance (newer radio ham
transceivers have built-in antenna turners). I have both but
my antenna tuner does not operate at the LoRa frequency. I
would not bother trying to build a homemade Lora antenna.
Decide what antenna gain (DBi) you require and purchase one
at <a href="http://amazon.ca" target="_blank"
moz-do-not-send="true">amazon.ca</a>. Stubbies are
relatively cheap (2DBi, $13) with prices going ains for pole
mounted high gain ones.</div>
<div class="gmail_default" style="font-size:small"><br>
</div>
<div class="gmail_default" style="font-size:small">Jim</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Thu, Apr 14, 2022 at 4:33
AM Deid Reimer <<a href="mailto:deid@drsol.com"
target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">deid@drsol.com</a>> wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div style="zoom:0%">
<div dir="auto">Hi Dave, <br>
<br>
</div>
<div dir="auto">I don't have a spectrum analyzer, although
it is on my list of things to acquire soon.<br>
<br>
</div>
<div dir="auto">A couple of videos worth watching on
building antennas. The bottom line, if you build it to
specs the vswr should be acceptable. <br>
<br>
</div>
<div dir="auto"><a href="https://youtu.be/eQEmFlMW50o"
target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">https://youtu.be/eQEmFlMW50o</a><br>
<br>
</div>
<div dir="auto"><a href="https://youtu.be/6cVYsHCLKq8"
target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">https://youtu.be/6cVYsHCLKq8</a><br>
<br>
<br>
</div>
<div dir="auto">Deid<br>
</div>
<div dir="auto">va7rei</div>
<div class="gmail_quote">On Apr. 13, 2022, at 10:25 p.m.,
George Bowden <<a href="mailto:gtbowdeng@gmail.com"
target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">gtbowdeng@gmail.com</a>>
wrote:
<blockquote class="gmail_quote" style="margin:0pt 0pt 0pt
0.8ex;border-left:1px solid
rgb(204,204,204);padding-left:1ex">
<div dir="ltr">Hi Dave. I've forwarded your query to
the projects group. That is the best place to get a
response, where more people can see it...
<div>I dont think a spectrum analyser is needed. You
could attach a dipole of the right length, depending
on the frequency you choose for the lora . at 915
mhz it could be made from a couple pieces of copper
wire, attached with a uFL to the lora module, if
that is what it has...</div>
<div><a
href="https://www.omnicalculator.com/physics/dipole"
target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">https://www.omnicalculator.com/physics/dipole</a>
is a dipole calculator, which says two wires each
16.4 cm long would make a dipole.</div>
<div>Deid is the one to answer antenna questions...
He's a ham operator.</div>
<div><br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">----------
Forwarded message ---------<br>
From: <strong class="gmail_sendername"
dir="auto">Dave Gates</strong> <span
dir="auto"><<a
href="mailto:dbgates@gmail.com"
target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">dbgates@gmail.com</a>></span><br>
Date: Wed, Apr 13, 2022 at 8:52 PM<br>
Subject: a couple of quick questions<br>
To: George Bowden <<a
href="mailto:gtbowdeng@gmail.com"
target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">gtbowdeng@gmail.com</a>><br>
</div>
<br>
<br>
Hi George,<br>
<br>
First: does anyone in the group have a spectrum
analyzer?<br>
<br>
The antenna with the LoRa modules looks like the
recommended one (as per <br>
the video you sent me) but I have no way of
knowing for sure... the <br>
video mentioned that if enough of the power sent
to the antenna is <br>
reflected back, it can heat up and even damage the
circuit.<br>
<br>
... I may be able to borrow a FLIR camera from a
friend of mine - so <br>
second question: if a spectrum analyzer is not
available, what are your <br>
thoughts on using a FLIR camera to avoid damage?<br>
<br>
Thanks!<br>
Dave.<br>
<br>
</div>
<br clear="all">
<div><br>
</div>
-- <br>
<div dir="ltr">
<div dir="ltr">George Bowden 250-893-7423
<div>Victoria BC</div>
</div>
</div>
</div>
</div>
<pre>--
Projects mailing list
<a href="mailto:Projects@vicpimakers.ca" target="_blank" moz-do-not-send="true" class="moz-txt-link-freetext">Projects@vicpimakers.ca</a>
<a href="http://vicpimakers.ca/mailman/listinfo/projects_vicpimakers.ca" target="_blank" moz-do-not-send="true" class="moz-txt-link-freetext">http://vicpimakers.ca/mailman/listinfo/projects_vicpimakers.ca</a>
</pre>
</blockquote>
</div>
</div>
-- <br>
Projects mailing list<br>
<a href="mailto:Projects@vicpimakers.ca" target="_blank"
moz-do-not-send="true" class="moz-txt-link-freetext">Projects@vicpimakers.ca</a><br>
<a
href="http://vicpimakers.ca/mailman/listinfo/projects_vicpimakers.ca"
rel="noreferrer" target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">http://vicpimakers.ca/mailman/listinfo/projects_vicpimakers.ca</a><br>
</blockquote>
</div>
</blockquote>
</body>
</html>