#188 Antenna Tutorial incl. cheap DIY Antenna Tester (LoRa, ESP32)

Everything goes wireless these days. This is why we have a close look at the “black magic” of antennas, how they work, what is essential, and how to test them.
Based on this knowledge we will build a cheap antenna tester for LoRa antennas. A similar device can be built to test Wi-Fi antennas.
It uses an ESP32 TTGO board on one side and a Wemos D1 mini with a Hope RFM95 module on the other side.

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[doggo]

I can't thank this guy who Andreas chooses to take his own time to share his huge knowledge with us, making video after video.
It's people like you that make the world great.

[aboosh]

nice to see my entire bachelor degree summed up in one video, great content !

[Willam_J]

Excellent video, Andreas. I fly model aircraft at a flying field which is about 1.25miles (2Km) from my home. I have have a weather station at my home, which other club members can access, to check flying conditions before traveling to the field. A few of the members expressed concern about the accuracy of the weather data, even though the whole area is farmland, my home is at the same elevation as the flying field and I have no obstructions around my weather station. To appease these members, I placed a second weather station on an existing tower at the field and linked it to my home network, through a secure gateway, with an ESP3266 based link. Even though the readings were the same, they still preferred to have wind speed and direction readings right at the field. I made it a permanent installation using a solar panel, charge controller and a LiPo battery pack enclosed in a weather-proof enclosure. Using yagi antennas between my tower and the tower at the field, I am able to maintain a very stable link on 915MHz with only 25mw of RF power. You’re very correct about using good quality, short lengths of coax cable. Just like a piece of chain, an antenna system is only as good as its weakest link. As always, I’m looking forward to your next video! Take care! :-)

[rollbeats]

Never seen any RF tut as detailed as this. Even from time I was at Uni. This had me getting communication electronic...BRAVO

[Conservator.]

Hi everybody, lets try to improve Andreas’ like/view ratio! 15.4% is not bad at all but I think we can do even better ;-). He surely deserves it!

[sethalump]

I've been an antenna / RF nerd for decades. This is the best explanation of all the important factors I've ever seen. (Also a nice review for the old timers) Good

[Lew]

Thank you for taking some of the mystery out of antennas. I always assumed that understanding them was simply over my head. Now I’m interested in trying to learn more. I look forward to future videos on this subject.

[arigetas]

This video contains the most crucial points on how the antenna and transceiver worked and felt light to digest. Thanks a lot.

[linuxranch]

I stand in awe of your ability to take tremendously complex subjects, and simplify them "just enough" to make them understandable. (Without "simplifying" them so much that they become "wrong"!)

Had I had you as an instructor, so much of the material I struggled with would have become stepping stones, rather than "avalanche debris".

Thank you. (Which sounds so inadequate for the work you do, and the insights you share.)

[mojoxide]

This needs to be a required video for anyone getting into this. Explains everything relevant, in one nice neat package.

[SteveWrightNZ]

Excellent!! This is a very good absolute-beginner introduction, and it is technically exactly correct, thank you Andreas. Regarding the legality of adding antenna gain, yes you must lower the transmit power to stay inside the EIRP power limits, BUT remember that the gain antenna ALSO works on receive so you get your "lost power" back again at the receive end! The cheap N1201SA analyser will show cable loss. Antennas are like fittings for your garden hose - you use a shower fitting for wider coverage and less range, or a squirty nozzle for longer range and less coverage.

[cabe_bedlam]

Thank you for also spending some time on the legal use of the RF. So few people appreciate that the aiwaves are shared.

[johnwest]

Thank you. I get tired of explaining these same things over and over to others. I'm willing to, but this is so much better. Now I can just refer them here. Your videos are complete and clear, and access is at the touch of a button. And neither of us has to say the same things over and over. That's hard to beat.

[ArztvomDienst]

Content like you are producing is the real value of youtube.

[neppub]

I'm not studying any engineering but always was thinking of how this work. Exactly the content needed. Thank you so much sir for giving us your precious time

[rodericksibelius]

I took a 9 month course in Microwaves taught by a retired Stanford Electrical engineer and had a school and had hired practicing electrical engineers from the microwave companies here in Silicon Valley, we learned the history of microwaves, the practical physics and the mathematics, the use of the Smith Chart, vector network analyzers, spectrum analyzers and how stripline microwave amplifiers were currently designed, this was way back in the mid' 80s. It's is great that we have THESE SMALL high tech test instruments now like this one - I know microwaves is 'black magic' to technicians and rf engineers.

[vaibhavhayaran]

I'm having antenna and wave propagation as a main stream subject this semester ( 3rd year electronics and communication engineering ) I'm so glad I found your video right before the final examinations. I haven't had a clue about what the professor taught ( he followed a very impractical approach and nobody had a clue about practical applications of antenna i think even he didn't) . after watching your video now, I'm able to understand and relate the subject completely.. thanks!

[MikeKranidis]

Dear Mr. Spiess I think this is one of your fascinating research. Let me congratulate you.

[zachhoy]

at 2:50 before the content appears, the cryptic screenshot is "The Power of the Sender depends on: Andreas Spiess". For me, this is 100% accurate.

[gtev]

Great stuff - I do this for a living and still enjoyed it. Well done. :-)