Frequently Asked Questions Q1: Does the length of coax effect signal loss. A1: Yes, at these frequencies loss is much greater than sub 30 MHz. However, the calculated loss with the type of coax I am using and the length used is around 0.6dB. So it's marginal. Q2: What type of coax are you using? A2: I am using Formula Zero, equivalent to Westflex 103 Q3: Blah Blah Blah Downtilt. A3: No idea that you are on about, but the angle of radiation is 8 degrees vertical and 360 degree omni, please look at the specs on the website for more info. Q4: Is the antenna too close to the other on the mast A4: Its known that antennas should be at least a 1/4 wave apart on the lowest frequency. The other antennas lower frequency is 145MHz, so around 50cm. So it's borderline but do plan to move it soon. Q5: Will the other antenna de-sense the 868 antenna if transmitting. A5: Possibly if I was transmitting high power on UHF. However, personally, I don't use that antenna for transmit very often. Q6: Using something else "blah blah" is better than self amalgamating tape. A6: I am using what the antenna manufacturer recommended. Although I will consider changing this when I move the antenna. Q7: With that much gain is it making it illegal to use in the uk. A7: ERP at the full 22dBm from the node would be over 1 Watt, so yes it would be. However, we can limit the power output in meshtastic. Remember that I mentioned I will use this antenna for other projects, not just meshtastic. Q8: How do you handle lighting protection? A8: I don't, but if I was worried about this then I would most likely buy a lightening arrester to go inline, however this would add loss. Q9: How does this antenna have so much gain. A9: It has a 16-element collinear dipole inside. Please do NOT reply to this pinned comment, ask new questions below. Thanks Matt.

I got 80 miles to the isle of man with the supplied antenna that came with my heltec v3 . . . . .

Currently got a loft installed Paradar 12.5 dBi Yagi pointing at TechMind's nodes some 20'ish km away and work very nicely 👍 Tried a 8.5 dbi Paradar omni before and while rx'ing was improved, transmitting was miss-more-than-hit. That's now hooked up to an additional node that servers the local Buckingham area.

It might help with longevity to apply a layer of of UV resistant PVC insulating tape over the self amalgamating tape.

Thanks for the video!!

Had one of these for helium mining. Try checking the SWR of just the top half. 😉

Great video and looking forward to the Yagi's performance.

I bought a bunch of 11dbi high gain antennas for my 5ghz WW-DRT wifi client bridges... and when I swapped them in for the stock 2dbi antennas bundled by the manufacturer, the 2dbi antennas ended up working just as good or even better. So I sent the 11dbi antennas back and got my money back. So never assume something is working and test the before and after by looking at an actual signal strength measurement in whatever radio software you are using wit one antenna, then the other. Once you find the best, then experiment (further) with tweaking aiming and location.

Well done.

Something to take into consideration up 800-900MHz is your SWR will read better because the loss of the reflected power in your transmission line. SWR is proportional to the reflected power at the point of measurement. If you’re losing 3dB return trip at the test frequency, then your SWR will be lower. To get the true SWR, you need to measure that at the base of the antenna, or, if you don’t want to climb a ladder, you can calibrate the transmission line out You can also measure the loss of your cable by measuring S22 log mag on the NanoVNA

Bedankt zos gaat door

I think I'll make a quarter wave ground plane antenna for under a fiver first, Matt. Welding wire and a panel mount BNC socket make a resonant antenna fit for a try out 73 de David M0YDH

You need to add a few layers of tightly wrapped quality (3M) vinyl tape on top of the self amalgamating tape. This compresses the amalgamating tape creating a water proof seal & protection against the elements.

Cool, i was wondering what to do with my old helium setup which includes this antenna and coax, I may as well throw a node onto the system, I’m 200m ASL in Shropshire.

A Turbo Antenna setup would be a (Quad phased Antenna Array) 4 of those Yagi's individually Pointing (North / South / East / West) 💪(You May possibly receive Nodes From France😊😊)

I recently monitored the 915 MHz (for US and Canada) here at Port Alberni BC Vancouver Island Canada using my RTL SDR and a small homemade tuned 1/4 wave ground plane and 2 feet of LMR 400 with RTL dongle high up with the antenna 10 feet above my porch. it is packed with twice as many signals, much to my surprize. I just ordered my new T-Echo and accessories still in shipment. I saw these 30 inch or higher oversized LoRa whip antennas at the Rocklands website catalogue. I was kinda skeptical of its capabilities being so big like a conventional 27 MHz CB antenna. I may look into these high gain omni antennas in the future.

Do you transmit with the other old antenna at all? I'd be afraid of frying the input of the LoRa device..

Wow was chuffed to See my Node Seaker101 in Bedford, I assume your node is MATT? I have three node, Pole1 (temporarily slung in the loft, like you I don't like ladders either so waiting for son-inlaw to install . I have Window1 taped to the window. And Seaker101 is now my mobile node for car and hill tops. My pole is not up yet and I already have pole envy :)

Love the bass boutique - (history of) Jungle shirt/hoodie

I live in the hilly hills and dells north of Boston MA. My 9 dbi antenna is up 30 feet from my 190 feet ASL. On the same Tower, I've got a 1090 plane tracker 9ish dbi that can hear planes out to 150 miles. Unless they are flying low, like when landing in Canada. It's line of sight only. My recommendation is not to use highest gain antenna, IF you have a great location, up high. Your LoRa signal pattern (very flattened donut) will pass overhead of any nodes in the local area. But might be good, for distant nodes in high locations. The mobile node in the pocket of someone inside a building a few miles away, might not hear enough signal.

How do you handle lighting protection on something like this?

The two antennas are close together, if you transmit on one will it blow up the Meshtastic node?

there’s a number of us in newport pagnell - but we are in a bit of a dip unfortunately

Do you know any manufacturer that sells similar antennas but for radiosonde frequencies? I find only for Lora and adsb

I am picking you up in south Dunstable all the time but unable to get back but then I am using a smaller antenna than you maybe I need to instal some thing similar to you

Are you thinking of trying 433MHz? I've got a 5 element yagi pointing your way. I'm in Welwyn Garden City so it might be possible

What crank mast did you use?

using this antenna without reducing the TX power of the node will take you above the legal transmission power of secondary users of the ism band

Instead of the ugly tape you can use heat shrink tuning that has a sealant built in. They are removable too as the sealant int hard to get off when done purposefully

Time for a change in thinking if meshing, rather buy 4 nodes and distribute them between friends in town on hills if you can.

I'm struggling to see how a vertical antenna can have any gain over an isotropic antenna. Maybe it's my lack of knowledge.but I am curious.

God bless.

I didn't see any wind loading data. At over 7FT that doesn't look like a very strong mounting point.

Will this be a quality antenna for 915 MHz?

Use bandpass filters to cut out RF noise. Especially with good antennas at high locations. This will drastically improve your range. Also LMR400 or better is a must if you're antenna requires more than a foot or two of coax cable. Also the industry standard for tape of any type to water proof is to create a staircase style wrap. From top to bottom, then without breaking, go from lower bottom to higher top. If you're short on tape, do at least one clean run without breaks from bottom to top so water beads can flow down and off like roof shingles.

1:21 - Surely those two antennas are detuning each other?

2.2m antenna for 33cm wavelength signal? I don't understand

With approx. +22dBm output from the transmitter and +11.5dBi of antenna gain relative to an isotropic radiator, doesn't this place you above the +27dBm ERP level for 868MHz Meshtastic? Be good and if you can't be good, be careful!

Why don't they supply a waterproof join. Its like selling faulty equipment

This co-colinéar antenna is good for summit not for low altitude ! the radiation pattern goes downward on this antenna with a lot of gain, in the configuration of a flat area your waves go with gain into the ground rather than towards the horizon! the performance is not at its maximum what is possible with this antenna on a plain

That's an expensive antenna.

I guess you're making it a little bit illegal since you're adding 11dBi of power (the regulations mention 25mW of ERP power)

This is bad info do not run long runs of coax as we are dealing with signals in the noise floor so the tiniest bit of coax loss and bye bye distant nodes as for high gain antenna will overcome this errr no not with the way lora works it's better to install with zero coax and a smaller gain antenna especially for ppl lower down.