002 How to build performing antennas for LoRa, WiFi, 433MHz, Airplanes etc NanoVNA, MMANA GAL

[@atomikrobot300099]

This is great that you've split out the ham radio videos. I've always wished you did more radio projects on the main channel. Your TinyGS video convinced me to buy Heltec dev kits as gifts for my ham radio friends! 73

[@HB9BLA]

These Heltec an TTGO boards are golden. We use them for 70APRS, for example.

[@IK8XOO--Paolo]

My suggestion for a satellite antenna is a circular polarized antenna, of course. The reason is simple: in the space words like "vertical" or "horizontal" does not exist and if the receiving antenna does not use the same polarization, there are 20 dB of loss !!! So almost all satellites use circular polarization (same sense = no losses). If the terrestrial station uses a linear polarization (vertical or horizontal) and the satellite uses a circular polarization, there will be always 3 dB of loss. The most common omnidirectional antenna showing a convenient radiation lobe for satellites is the "turnstile" (not all the projects on the web are correct...) but the circular polarization is achieved only at high elevation angles and the radiation lobe can be improved. "Quadrifilar Helix" antenna should be better, but it is more complicated to build. I'll try soon an improved version of Lindenblad Antenna. 73s.

[@HB9BLA]

I did not check all CubeSats, but the ones I looked at had simple dipoles. I agree with your statement on circular modulation, but my setup currently gets signals from 2000km away where the transmit power is 500mW. LoRa has a very high link budget...

[@matambale]

A video on DIY Yagi antennas for this frequency range would also be useful and interesting, sir, especially given your gift for maximizing quality and minimizing cost.

[@HB9BLA]

We will see where the channel will drift. But antennas for sure are a topic here!

[@fase144]

A very useful and interesting video. Thank you!

[@HB9BLA]

You are welcome!

[@tarsamsingh1299]

I agree

[@catcam]

Thanks for new channel !!! All best from Croatia.

[@HB9BLA]

You are welcome!

[@acestudioscouk-Ace-G0ACE]

Useful information well explained as usual, thank-you.

[@HB9BLA]

My pleasure!

[@pjn1988]

It would be very interesting to see some practical builds of circular polarized antennas 🤔 They are supposed to perform very well in bad conditions, e.g. like in a forest.

[@HB9BLA]

We will see. Both antennas have to be circular for the advantages. And often we only can decide on one because the other belongs to somebody else…

[@75EOS]

I used to make antennas for 27CB with a matching coupler and for RX (aerial band mainly with coax balums). I've been always afraid to make antennas for 2.4/5 because SNR. Very interesting your meter, I'll take a look a it! Improve 2.4G for espnow is very interesting. thanks once again for your work!

[@HB9BLA]

Good luck with your experiments!

[@minazulkhan8287]

Great video. Learnd a lot

[@HB9BLA]

Thank you!

[@ImnotChuck.]

I have built ground plane antennas for frequencies up to 147 MHz, but have never known that putting the radials at a 45 degree angle was critical. Thanks for the explanation.

[@HB9BLA]

These small VNAs are very valuable to see the effect of changes in the antenna design. So it is more fun to experiment with antennas…

[@SteveWrightNZ]

The J-pole is an excellent introduction to antenna building, because it is two parts in one - an impedance transformer and a 1/2y dipole. If you build the transformer first and match it into a 3Kohm resistor then it is easy, just adjust the overall length and feedpoint for a match. Once you have this mastered, then try a slot antenna, that will wreck your brain lol

[@HB9BLA]

Indeed, the J-pole is an interesting antenna to learn. Without explanation it looked rather strange to me.

[@Magic-Smoke]

Very good, Andreas. One question though, were you really soldering aluminium welding rod or did I misunderstand? If you were, what solder/flux were you using please?

[@HB9BLA]

It was a welding rod for aluminum. So I do not know the exact materials. Later I found a similar product with a copper surface for "hard soldering" also on ebay. This is much easier to solder. Both are not expensive and you get them in the length of 1M

[@Magic-Smoke]

@@HB9BLA Thank you.

[@ThiemoEn]

Great Video. I would be interested in how to build a directional (eg Yagi-) Antenna for LTE or 5g cellular networks. Maybe a topic for a future Video?

[@HB9BLA]

So far I have no experience with such antennas. Maybe you check this channel: kzbin.info

[@DieSonneSchicktKeineRechnug]

Schön das du diesen Kanal aufgemacht hast. Wenn es dir nicht zu viel Arbeit ist würde ich mich über eins Schweizer Deutsch Variante freuen. 73 de DH3BAR, Michael

[@HB9BLA]

Ich werde den Kanal weiterhin in Englisch machen, auch ohne Spanische Untertitel. Ich musste meiner Frau versprechen dass ich den Aufwand nicht allzu hoch fahre ;-) Aber wir planen im Rahmen der USKA eine Ausbildungsserie in Deutsch und ich denke dass da der eine oder andere Inhalt von diesem Kanal kommt (oder umgekehrt)... Alles wird sowieso open source sein weil es sich hauptsächlich an angehende HAMs richtet. Vielleicht können wir ja noch ein paar Deutsche HAMs für eine Mitarbeit gewinnen...

[@fotografm]

What a great video ! It is really informative. You very briefly mentioned "return loss" but then didn't go into it. Also right near the end at the J-Pole antenna I am not sure what happened as the VSWR is printed as 151951 or so. For the sake of beginners we need to ask if this was probably 1.5 ? Also the impedance looks a little strange at 2.3 Ohms (real part).

[@HB9BLA]

I do not know what you refer to :-(

[@youpattube1]

Excellent, excellent video. I understood most of it. With regard to the calculator showing 17.7 cm, and you trimming it to 17. Did you say that you substituted aluminum for copper? Is the velocity factor the same?

[@HB9BLA]

I used a sort of metal where I do not know the composition (a welding rod). But for sure not copper. The VF is different. Otherwise the optimal length would not be different.

[@OxOOCOFFEE]

​@@HB9BLA Is copper vs aluminum better? Should one always prefer higher VF over lower?

[@HB9BLA]

@@OxOOCOFFEE AFAIK the VF has no influence on performance, only on dimension. Copper has very different properties (it conducts a little better which is good) but is expensive.

[@Cyklonus]

👍

[@OxOOCOFFEE]

How do you pick the best ground plane angle to vertical? does change angle change antenna SWR across the different spectrum?

[@HB9BLA]

1. By trying 2. Yes

[@MrAbrandao]

how about a video explaining the use of two antennas at the same time to scan two frequencies with the same circuit?

[@HB9BLA]

Currently, I do not have an application for such a scenario :-(

[@fp2634]

5:15 I was wondering if I should consider any skin effect when choosing the antenna copper wire? And also, would multi strand be better than simple wire? Thanks in advance, and thanks for your passion sharing!

[@HB9BLA]

I do not know enough about the skin effect :-(

[@SteveWrightNZ]

You have to have a basic VNA if you're building antennas, or else its just too hit-and-miss. Get one, they're cheap and great fun to use.

[@phurla1]

Thanks for the video. You indicated PL 239/59 are used up to 100Mhz. What about for recieving only? Would N type vs UHF type make much difference for example at 1090 Mhz?

[@HB9BLA]

They use it also on 2M rigs. So I assume it is not critical around 150MHz. 1090MHz is much higher. I would not use it because you have better choices. But I have no solid data.

[@zeno2712]

When measuring the length for the vertical, I think the length is from the tip down to the reference plane of the SMA connector (because the pin on the connector is part of the vertical), but for the radials, when do you measure to? Do you measure from the tip to the centre of the mounting plate of the connector or is it just the length of the rod (plus the mounting tag)? It maybe doesn't matter too much for lower frequencies but it may make a difference for frequencies above 433 MHz.

[@HB9BLA]

I measure too long and cut it according the measurements. But you are right, the length is measured from the end of the ground

[@phurla1]

Also, is ther an advantage of a full wave over a quarter wave ground plane antenna for 1090Mhz?

[@HB9BLA]

Longer antennas in general are better. But keep in mind that the impedance of an antenna always has to be matched to the coax.

[@pivertigineux]

Thank you for this great quality content! Should I test an antenna with the final cable length attached? For example, if I have to run a 1m coax cable between my antenna and the receiver, should I include the cable when using the NanoVNA?

[@HB9BLA]

Maybe you also watch the video about the nanoVNA. But a short answer here: If you want to test the antenna you have to do it without coax. If you want to protect your transceiver you have to measure at the end of the coax where the transceiver is mounted.

[@pivertigineux]

@@HB9BLA Thanks for your answer. I also watched the video about nanoVNA but as you showed us : "an adapter or cable invalidates calibration" and I was wondering if the cable going to the receiver could act as part of the antenna (ADS-B collinear coax antenna) and if I should take it into account when doing measurements.

[@AndreasSpiess]

@@pivertigineux The reference plane is the interesting part.

[@SteveWrightNZ]

If you must have a test coax on your antenna, then first cut yourself a 1/2y length of cable and get it exact. Remember that a 1/2y section of coax is a 1:1 transformer, quite the opposite of a 1/4y wave section which will transform a short to an open and vice versa.

[@protektwar]

What if you use 5 telescopic antennas? So that you can make it adaptable for different frequencies...

[@HB9BLA]

No problem. That will work.

[@justinbauer6095]

What type of coax do you use to connect your antennas to your sdrs?

[@HB9BLA]

That depends on the length of the cable. Rule of thumb: The longer and the higher the frequency the thicker (and more expensive) the cable.

[@billyjoe3309]

For WiFi, the ground radials, can they be the device PCB?

[@HB9BLA]

Yes. But then you might not get the desired 50 ohms...

[@TheMcSebi]

Does the receiving antenna also need a ground plane?

[@HB9BLA]

Yes. But receiving antennas are less problematic if they do not expose the right impedance because only the signal gets weaker, nothing more. Transmitters can be destroyed in this case.

[@phillipneal8194]

Is there such a thing as a ground plane antenna for 20 meters ?

[@HB9BLA]

Yes. But it is a little bigger ;-) Google DXcommander, for example

[@AxelWerner]

Where is the odysee mirror ?

[@HB9BLA]

So far I my main channel is on Odysee with extremely limited success. I have no plans do it with this channel.

[@AxelWerner]

@@HB9BLA in that case here is some motivation for you. I'll unsubscribe to both of your channels on yoochoobs now and stay subscribed on Odysee. C u there.

[@HB9BLA]

@@AxelWerner No problem for me.