I built a new 868Mhz quarterwave groundplane last week. I'll pop a picture on Andy Kirby's Discord's meshtastic-antenna-chat because it is probably the most attractive antenna I've ever made when every other quaaterwave groundplane I've ever made looked like something out of Mad Max :)
Re the 'pokey' ends on the ground plane antenna - go to your local hardware or garden store and get some plastic wire nuts (puck a nice bright colour). Once the antenna is tuned up, take a file and roughen the last 5mm or so of the radials and epoxy the wire nuts on the end. The wire nuts will make the ends easier to spot and stop them from jabbing you.
These will probably detune the antenna. The far end of those elements is a high-impedance part of the radiator, and easily affected by the presence of some other material attached to it. Even more so if the wire nut has a metal spring in inside.
Great video. I made one of these with 1.4mm copper wire. The swr was 2 ish so I added more ground elements and now it’s 1.4. I made a second one of measuring tape and it’s 1.5 swr.
I think I might venture to have a go at this. Found in my bag of connectors a N type chassis socket, still in its bag from Maplin, so maybe that should go into the history museum instead.
tbh it's how films are shot these days always so called "CNN cam", your lighting is 1,000,000 times better than most modern films though like dune - the future with forcefields but we haven't invited cheap LED lighting, It's the content that is important. Practical and interesting@@fotografm
This is very convenient for me I am doing the same tests rightnow with the same equipment because I started with Meshtastic recently. I also wanted to check a J pole antenna.Meshtastic is not that populair in NL perhaps it will grow in the future here. Thanks for this nice video
Glad you liked the video. I think that Meshtastic has revived interest for a lot of people. I am rediscovering techniques from a long time ago but with modern hardware and test equipment. It's a lot of fun. The Mesh is getting quite big in UK. I hope it will increase in NL too. I wonder how is the takeup in other EU countries ?
I understand you wanted to keep it cheap and simple. I would have used a commercial antenna mount and a double colinear antenna for gain since you are operating in the flea-power range where every Db counts. At 800MHz and higher, such antennas are still fairly small and manageable.
Brilliant video! I'm quite curious how much loss is happening in the feeder cable? That thin coax is rather hard on WiFi frequencies at least and for long distance WiFi feeds I ended up using LMR400 which then needed adapters that introduced more loss but the total was far below the loss from smaller diameter feeders.
You are right to be concerned. It's actually a cable that came with the VNA which is specced up to 1.5GHz so hopefully the cable is reasonably good there too. 868MHz is luckily quite a bit lower in frequency than the 2.4GHz WiFi you mentioned.
The effect will be absolutely minimal, even if the plastic should happen to be lossy, since such a small porion of the length of the radials is in the vicinity of the plastic. There will also be a minimal lowering of the resonance frequency of the radials due to the dielectric effect, but again this will be minimal.
I have made a few of these using brass tube for the driven element and an old coat hanger for the radials. seems to match your performance with the exception that best SWR Performance is achieved with the radials at about 10 degrees off horizontal. Is swr the only thing we need to consider? is there another unmeasured benefit from increasing the angle of the radials n
I used coathanger wire too back in the day. I remembr that for 2 metres it had to be 19 inches long ! For me, SWR is important since it relates to how much power is transferred between the antenna and the radio - both on receive and transmit.
I LOVE That I Got Copper Like, Hundreds Of Kilograms For Cents Bback In The Day, Now When Im Making Antenna I Have Loops Of Loops Of Copper Wires, Thick, Think, Smaller Then Hair, Even Like Ingot Size, But Its A Wire, Wire From OLD USSR Welding machine, the wire thickness is 5mm And Width Is 1cm and its hardened so whenever i want o makme something out of it i just cut it off and if i need to make it softer i just put the torch on the wire, if yiu can call it a wire ;D made doorhandles for the whole house because copper is killing viruses in 10minutes and steel kills viruses in 3 days for comparison and when you ahve copper doorhandles all around the house, it counts , i havent been sick since i put them on, but higiene is always needs to be done to you know, but jeah, i have tens if not hundreds of kilometers in various copper wire. also what i got is so much ussr soviet made components, germanium diodes and everything, all that costed me like nothing compared if i would buy it all frome bay or marketplaces. :) Sweet video, that snipping part resonated with me cuz i did the same :D
I made these for 2.4g wifi back in 2010. They did not work well. The ground plane is highly distorted like a cloverleaf. Dipole is better for a tourus radiation pattern.
"loved your drumming work!" First reaction when I saw the 239 connecter in the placeholder in conjunction with Meshtastic I had bit of a raised eyebrow moment, but "what was at hand" ... I'd have done same. Amazon sell 5 packs of similar configuration chassis SMA for 16quid. "Superbat SMA Connectors SMA Female 4 Holes Panel Chassis Mount Flange Solder Cup Connector SMA Bulkhead Connector 5-Pack" Chuckled when you showed your fave' antenna, at first glance it was very similar (but not the same as) Andy Kirbys dodgy one - the youtube placeholder pic says it all :- th-cam.com/video/Y4qXn_gOTY8/w-d-xo.html Good video, many thanks for sharing dude.
i would of gone for Pipe Screw End caps - also look up lasersaber - DIY SOLN1 - Portable Solar Power now yoiu can gave a nice Flashing RED LED Beacn Powered by mains
Excellent work Simon & thank you for sharing .
Many thanks, Julian.
I built a new 868Mhz quarterwave groundplane last week. I'll pop a picture on Andy Kirby's Discord's meshtastic-antenna-chat because it is probably the most attractive antenna I've ever made when every other quaaterwave groundplane I've ever made looked like something out of Mad Max :)
That sounds great - will go and take a look at your beautiful creation !
I did a very similar build! works well! Thanks for sharing.
Re the 'pokey' ends on the ground plane antenna - go to your local hardware or garden store and get some plastic wire nuts (puck a nice bright colour). Once the antenna is tuned up, take a file and roughen the last 5mm or so of the radials and epoxy the wire nuts on the end. The wire nuts will make the ends easier to spot and stop them from jabbing you.
Thanks for the tips!
These will probably detune the antenna. The far end of those elements is a high-impedance part of the radiator, and easily affected by the presence of some other material attached to it. Even more so if the wire nut has a metal spring in inside.
I only interface with my VNA through software, I find the menus and calibration much easier that way. I use NANOVNASAVER software
Thanks for the tip. I will give it a try !
Very impressive! Thank you for the video.
Thanks for watching!
Great video. I made one of these with 1.4mm copper wire. The swr was 2 ish so I added more ground elements and now it’s 1.4. I made a second one of measuring tape and it’s 1.5 swr.
Nice work!
I think I might venture to have a go at this. Found in my bag of connectors a N type chassis socket, still in its bag from Maplin, so maybe that should go into the history museum instead.
The best thing to do is to put it to use :-)
Hi, after watching your videos I made the same and it works well. Thanks
Great to hear!
Brilliant & interesting. 👍
Steven Spielberg would be proud of the filming 😀😊
Wow, thank you! Maybe I should get a steadycam and clapper board ?
tbh it's how films are shot these days always so called "CNN cam", your lighting is 1,000,000 times better than most modern films though like dune - the future with forcefields but we haven't invited cheap LED lighting, It's the content that is important. Practical and interesting@@fotografm
This is very convenient for me I am doing the same tests rightnow with the same
equipment because I started with Meshtastic recently. I also wanted to check a
J pole antenna.Meshtastic is not that populair in NL perhaps it will grow in the future here.
Thanks for this nice video
Glad you liked the video. I think that Meshtastic has revived interest for a lot of people. I am rediscovering techniques from a long time ago but with modern hardware and test equipment. It's a lot of fun. The Mesh is getting quite big in UK. I hope it will increase in NL too. I wonder how is the takeup in other EU countries ?
I understand you wanted to keep it cheap and simple. I would have used a commercial antenna mount and a double colinear antenna for gain since you are operating in the flea-power range where every Db counts. At 800MHz and higher, such antennas are still fairly small and manageable.
I used welding wire as I have a huge supply of the stuff
That's nice.
According to a Farnell data sheet, RG316 is about 0.86dB/m at 20 deg C.
Ditch the coax and put the node inside the drainpipe. Connect it with an active USB cable.
That is a very elegant suggesion !
Great video, thank you for sharing!
Thanks for watching!
Great video and inspiration to make my own antenna (Always a first)..
Thanks. Go for it!
Use the CW-Function in the Stimulus menu to transmit on a single frequency. I dont know what thats short for but Carrier Wave maybe?
Continuous Wave. Thanks. Found it :-)
Very much enjoyed watching this
Glad you enjoyed it
Good job 👍 I just ordered a t deck to play with
Hope you enjoy it!
Very interesting. Thanks for the video.
Glad you enjoyed it
Brilliant video! I'm quite curious how much loss is happening in the feeder cable? That thin coax is rather hard on WiFi frequencies at least and for long distance WiFi feeds I ended up using LMR400 which then needed adapters that introduced more loss but the total was far below the loss from smaller diameter feeders.
You are right to be concerned. It's actually a cable that came with the VNA which is specced up to 1.5GHz so hopefully the cable is reasonably good there too. 868MHz is luckily quite a bit lower in frequency than the 2.4GHz WiFi you mentioned.
We’re here for the antenna and you go off on a tangent with a spectrum analyzer
and a network analyser too ;-)
Some interesting techniques there Simon
Thank you, Tony. Antenna building and testing seems to be raising quite a lot of interest.
How much does covering up the radials with a plastic cover affect it does it lose db
The effect will be absolutely minimal, even if the plastic should happen to be lossy, since such a small porion of the length of the radials is in the vicinity of the plastic. There will also be a minimal lowering of the resonance frequency of the radials due to the dielectric effect, but again this will be minimal.
@@fotografm cool I'm experimenting making one and making a 3D printed cover
@@markwilliams5654 Excellent. Publish your results to inspire us all !
I'm worried that the white shoe will give different results from the black booty radiator you used to use :)
I had the same thought...
I have made a few of these using brass tube for the driven element and an old coat hanger for the radials. seems to match your performance with the exception that best SWR Performance is achieved with the radials at about 10 degrees off horizontal. Is swr the only thing we need to consider? is there another unmeasured benefit from increasing the angle of the radials n
your impedance will change 45degrees give the 50 ohm impedance you need
The Smith chart is spot on 50 ohms at the same angle.
I used coathanger wire too back in the day. I remembr that for 2 metres it had to be 19 inches long ! For me, SWR is important since it relates to how much power is transferred between the antenna and the radio - both on receive and transmit.
What connector would you reccoment if building this type of the antenna ? as you said this one is not ideal for use...
N-Type !
I LOVE That I Got Copper Like, Hundreds Of Kilograms For Cents Bback In The Day, Now When Im Making Antenna I Have Loops Of Loops Of Copper Wires, Thick, Think, Smaller Then Hair, Even Like Ingot Size, But Its A Wire, Wire From OLD USSR Welding machine, the wire thickness is 5mm And Width Is 1cm and its hardened so whenever i want o makme something out of it i just cut it off and if i need to make it softer i just put the torch on the wire, if yiu can call it a wire ;D
made doorhandles for the whole house because copper is killing viruses in 10minutes and steel kills viruses in 3 days for comparison and when you ahve copper doorhandles all around the house, it counts , i havent been sick since i put them on, but higiene is always needs to be done to you know, but jeah, i have tens if not hundreds of kilometers in various copper wire. also what i got is so much ussr soviet made components, germanium diodes and everything, all that costed me like nothing compared if i would buy it all frome bay or marketplaces. :)
Sweet video, that snipping part resonated with me cuz i did the same :D
Lucky you !
I made these for 2.4g wifi back in 2010. They did not work well. The ground plane is highly distorted like a cloverleaf. Dipole is better for a tourus radiation pattern.
Thanks for the tip !
"loved your drumming work!"
First reaction when I saw the 239 connecter in the placeholder in conjunction with Meshtastic I had bit of a raised eyebrow moment, but "what was at hand" ... I'd have done same. Amazon sell 5 packs of similar configuration chassis SMA for 16quid. "Superbat SMA Connectors SMA Female 4 Holes Panel Chassis Mount Flange Solder Cup Connector SMA Bulkhead Connector 5-Pack"
Chuckled when you showed your fave' antenna, at first glance it was very similar (but not the same as) Andy Kirbys dodgy one - the youtube placeholder pic says it all :- th-cam.com/video/Y4qXn_gOTY8/w-d-xo.html
Good video, many thanks for sharing dude.
Thanks for your reply. I enjoy experimenting with what I have or with what is available.
👍👍👍
Glad you liked it !
@@fotografm 😊😊👋
Nice informative video, Thanks :)
Glad you liked it !
i would of gone for Pipe Screw End caps
- also look up
lasersaber - DIY SOLN1 - Portable Solar Power
now yoiu can gave a nice Flashing RED LED Beacn Powered by mains