[VicPiMakers Projects] Fwd: a couple of quick questions

[Dave Gates]

Thanks Jim,
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 
https://www.youtube.com/watch?v=CJNq2I_PDHQ  (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)

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.

Thanks for the info - I will do some research on what is available via 
amazon

Dave.

On 2022-04-14 12:33 p.m., James Briante wrote:
> Hi Dave,
>
> 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 amazon.ca <http://amazon.ca>.  Stubbies are relatively cheap (2DBi, 
> $13) with prices going ains for pole mounted high gain ones.
>
> Jim
>
> On Thu, Apr 14, 2022 at 4:33 AM Deid Reimer <deid at drsol.com> wrote:
>
>     Hi Dave,
>
>     I don't have a spectrum analyzer, although it is on my list of
>     things to acquire soon.
>
>     A couple of videos worth watching on building antennas.   The
>     bottom line, if you build it to specs the vswr should be acceptable.
>
>     https://youtu.be/eQEmFlMW50o
>
>     https://youtu.be/6cVYsHCLKq8
>
>
>     Deid
>     va7rei
>     On Apr. 13, 2022, at 10:25 p.m., George Bowden
>     <gtbowdeng at gmail.com> wrote:
>
>         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...
>         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...
>         https://www.omnicalculator.com/physics/dipole is a dipole
>         calculator, which says two wires each 16.4 cm long would make
>         a dipole.
>         Deid is the one to answer antenna questions... He's a ham
>         operator.
>
>         ---------- Forwarded message ---------
>         From: *Dave Gates* <dbgates at gmail.com>
>         Date: Wed, Apr 13, 2022 at 8:52 PM
>         Subject: a couple of quick questions
>         To: George Bowden <gtbowdeng at gmail.com>
>
>
>         Hi George,
>
>         First: does anyone in the group have a spectrum analyzer?
>
>         The antenna with the LoRa modules looks like the recommended
>         one (as per
>         the video you sent me) but I have no way of knowing for
>         sure... the
>         video mentioned that if enough of the power sent to the
>         antenna is
>         reflected back, it can heat up and even damage the circuit.
>
>         ... I may be able to borrow a FLIR camera from a friend of
>         mine - so
>         second question: if a spectrum analyzer is not available, what
>         are your
>         thoughts on using a FLIR camera to avoid damage?
>
>         Thanks!
>         Dave.
>
>
>
>         -- 
>         George Bowden  250-893-7423
>         Victoria BC
>
>         -- 
>         Projects mailing list
>         Projects at vicpimakers.ca
>         http://vicpimakers.ca/mailman/listinfo/projects_vicpimakers.ca
>
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