I'm probably wrong, but my understanding is that LoRa takes advantage of the spread spectrum between 902 - 928Mhz. You can set a channel offset to adjust the center frequency, but the default would be 0 and starts near the 902 end. For my purposes, I'm using the Very Long Slow channel with an channel offset of 210, which gives me a center frequency landing around 918 or so. The number of "channels" you setup in Meshtastic will increase in frequency accordingly. For my purposes I've setup a "private" mesh network and don't want to compete with other generic LoRa devices. Also after diving into this head first I've learned that resonance and capacitance chance with antenna position and plastic shielding. Your workspace looks awesome!

@JuliansRandomProject

3 ай бұрын

Ha! This work space is a mess and a reflection of how my brain works. I also figured it was a wide enough spectrum that 915 would be the middle and then the firmware would move around in that space. While the LoRa transmit pattern is spread spectrum, it’s not multiple MHz wide. Watching the nodes around my place communicate for a few hours with an SDR, it became obvious that the default ‘channel’ it’s using life’s for RX/TX at 906.875. I also moved the channel on a device and landed at 912mhz. Why a time to be alive with all these cool tools and options. Hope you can share what you’re using LoRa for. Godspeed

@nathanmatthews8172

3 ай бұрын

@@JuliansRandomProjectI’m setting up a LoRA / MQTT network in a somewhat remote mountain community for the purpose of SCADA alarms. We often loose power / cellular service in winter storms. I’ve jumped head first down the rabbit hole and purchased a Nano VNA, TinySA ultra and just recently a SDR software defined radio to observe communications and noise floors. Absolutely wild.

@jasongreene303

2 ай бұрын

​@@nathanmatthews8172You are a nerds nerd!

@tedpark6814

2 ай бұрын

The frequency used depends on the slot chosen, I'm using the defaults. I used an SDR to figure out what frequency it was using (it's documented too). I'd built some antennas that worked well, but for remote nodes I use commercial antennas since they're more resistant to weather and vandalism.

Thanks for the information here. I have been scanning trying to find the frequency and this is exactly what I was looking for.

Hey. The plastic cover changes the _velocity factor_ of the wire. So if you have a bare wire, it will appear electrically longer with the plastic over it It’s not so much any conductive material, more a dialectic effect that slows down the wave propagation along the wire, making the wire appear longer. Same effect you get with Coax cable. Hope that makes sense Keep experimenting, you’ll discover and learn so much Cheers :-)

@JuliansRandomProject

3 ай бұрын

Velocity factor, I’m aware of it but not enough to teach others just yet 😊. Same goes for the heat shrink on internal antennas. I’ve got them to tune by just removing some amount of the heat shrink. Thanks!

@MidlifeRenaissanceMan

3 ай бұрын

@@JuliansRandomProject cheers Got 2 more little V3 boards with antenna and case. Already had one. The second unit took less than 10 mins and I was on the air. Foolishly I only purchased one to start with. Couldn’t see anyone via LoRa I now have that on an antenna that was originally supplied with an old PSTN cellular gateway and had a nice dip at 915MHz without doing anything. I can pick up a couple of nodes that are local to me, but once I set it as a router with MQTT set up for our region’s topic, everything started coming through. Once I had the second unit on the air. It could see the first device along with all its MQTT peers Very impressed. Keen to see how many _furthers_ I can get out of the router unit with an antenna with some gain, located at a decent height

@x_CrossHair_x

2 ай бұрын

Sounds to me that you would need some Local HAM Radio operators to get on board .. Or get a Amateur Radio License.. So you can set up some Higher Power Repeater Nodes in the 33 cm Band (5 Watts) at least ... This system is a Low Power (No Licence) needed.. And similar to Packet or RTTY. Digital Communication Modes. (1/10th of a Watt) AKA 100 Mili-Watts (Won't get much range) think of the potential with Towers and Higher Power. 73s

@JuliansRandomProject

2 ай бұрын

@@x_CrossHair_x when using my ham license I have to turn off encryption. I’m only interested in Meshtastic to talk to non-licensed folks in a secure manor :)

You figured out the recipe of the secret sauce!

As the previous poster stated, if you really want private comms and you have the area covered it’s best to find a center frequency that has minimum traffic to use.

I eould recommend not having such high Q antennas. You want an antenna that is a bit more wideband and has swr less than 2. As you move around, change orientation, weather, etc your antenna resonance can change. If you have a very narrow bandwidth, it can get bad fast. There is a reason meshtastic has the testing report section. I recommend you use it.

watched from Bryan,tx... Starting Meshtastic in 1 week...

Nice logo, NSDQ. You are 100% correct above the actual frequency for LoRa Radios. Outside the LoRa Radio world it is common to refer to radio by the "center" of the radio frequencies they use.

@JuliansRandomProject

2 ай бұрын

NSDQ!

Australia and New Zealand have LongFast on 919.875MHz. The other presets are mostly between 915 - 920MHz (except medium fast and medium slow are 926Mhz and 927Mhz)

@JuliansRandomProject

3 ай бұрын

Great info! Thanks. Is there a term we can search for in the Meshtastic code to find the freqs used per setting/channel? I’ll grep for medium slow and the others to see if I find anything.

You can check your exact frequency in the Meshtastic app, in Radio Configuration under LoRa, it's listed as Override Frequency. In the EU this is 869.525MHz rather than the more rounded figure of 868 that you hear mentioned.

But did it work better, after you trimmed the antenna? As I have heard some of the antennas are not even close to the bandwidth needed for the frequency allocation. Good on you for making it work for your situation. 👍

@adammoss5284

3 ай бұрын

I think he’s right that they trim them between two marks on the workbench or something cause I measured a whole heap of antennas that have come with wireless gear and only two were on the nose, the rest were miles off. Your antenna could be 50mhz plus off resonance. Anyhow, hope yours aren’t but it seems every day at their antenna plants is a Friday 😉

@JuliansRandomProject

3 ай бұрын

Yes. Got 3 more miles out of it with this single change.

Yup, I was struggling with materials changing SWR. Is this the same Julian I met in Belton last weekend?

@JuliansRandomProject

2 ай бұрын

Velocity factor in effect with materials. If he was handsome... yes, same guy.

I have an update on what I have figured out, there is a place where you can change the frequency in the menu you can change the channel number which changes the frequency. I am going to configure my 4 devices to a frequency if possible that is still ion the range for LoRa but not the most common. I am looking to create my own network for my family who live within range of using the hop feature to keep in touch with each other. I also use the scan QR code feature to copy the channel info over to all the devices to keep it secure.

@JuliansRandomProject

18 күн бұрын

Love it! I'm getting about 6 miles right now with slightly larger 5dbi antennas. Would be smart to use a 'channel' that aligns better with your specific antenna if you don't need to interop with a larger mesh outside your family. very cool

Ah yes seen somewhere when messing with python cli that the device was at 906. And was confused. Forgot about that. Spent a day or two on my rtl sdr/HT/flipper looking for signals between 910-930 mhz confused then bam 906ish found em a finally.

First thing I did was check the frequency on my SDR RX to see where it was transmitting. Dead on 906 MHZ. I tuned all my antennas that came with them to that but the big antenna is pretty close so I will keep that as is or I will have to break the case to adjust it. I am working on the solar piece which has been a bear... I installed a USB charger to my 6 volt solar panel and it seems to charge the 3.7 300mah battery ok until it gets warm than it just stops. Gone thru 3 chargers. the Heltec seems to charge the battery if its a 5 volt source but above that it gets dicey. I am also working on connecting the HW 611 to get outside weather data. The pinouts are known for the V2 but V3 is a bit unknown to me and I am trying to find reference to which pin translates to the old V2.

@JuliansRandomProject

2 ай бұрын

Will from @AustinMesh did some experimenting with the voltages the charge controller accepted and rejected, worth a watch. Sounds like you’ve got this thing. Let us know how it goes!

Hi, can you link to the IPEX to SMA cap you are using? Thanks...

@JuliansRandomProject

3 ай бұрын

I'm using the iPEX to SMA adapters that came in this multi pack amzn.to/3vuulj6

Is that a Nintendo DS stylus?

@JuliansRandomProject

3 ай бұрын

Yep :)

Now with that Knowledge (Of the correct Frequency) Build a Coaxial Collinear Antenna (8 Segment At least) .. Don't forget the Velocity Factor of the Coax you use when Trimming the Segments. (With the Aid of your VNA) should help alot.. (Nice Discovery) for Peek Performance and Efficency. 👍👍

I purchased 4 devices and all 4 have died. Had them 2 weeks. They all died and YES I put batteries in After the antenna, JUNK!

@JuliansRandomProject

3 ай бұрын

Which model did you purchase and from where? I hear good things about the RAK wireless boards but haven’t bought them yet

How is the cover removed from the antenna, without breaking it?

@JuliansRandomProject

2 ай бұрын

Pull and wiggle.

@XavierDJohnson

2 ай бұрын

Same question! Im pulling and wiggling with no luck.

@ripenews

2 ай бұрын

Try a little heat. That worked for me!

@XavierDJohnson

2 ай бұрын

Pair of pliers and some balls and I got her loose. Thanks 🎉

Which case is that?

@JuliansRandomProject

3 ай бұрын

Simon Muzi’s H1 case for the heltec board. makerworld.com/en/models/160873#profileId-229552

@KowOneOhTwo

3 ай бұрын

@@JuliansRandomProject Thank you!

Another mistake you're making is tuning it for the wrong DUT.

@JuliansRandomProject

3 ай бұрын

DUT? Device Under Test?

@npc9352

3 ай бұрын

@@JuliansRandomProject yes

@JuliansRandomProject

3 ай бұрын

@@npc9352 what would be the correct DUT? I feel like I’m missing something :)

@npc9352

3 ай бұрын

@@JuliansRandomProject The device the antenna is used at, e.g. t-beam, t-echo. Remember: 1/4 wave is just a half of the dipole, so it uses the device and/or human (if you hold it) as another half, so its performance will depend on the device it is used with.

@JuliansRandomProject

3 ай бұрын

@@npc9352Correct. In this example I’m testing with the 3D printed enclosure that I’ll be using the antenna with and the exact length of coax from ipex to female SMA. I even when as far as buying a little ipex to make adapter for the VNA. This is the Device Under Test. I won’t be moving it to another enclosure or different ground plane without testing and adjusting again. Thanks for the feedback!

So much wrong in this video. Please learn more.

@JuliansRandomProject

2 ай бұрын

Are you ok?