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Antennas

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(@tedbear)
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Joined: 5 years ago
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Got the enclosure mounted. I tried the unit with the external just dangling out the front without a cover. I got what I felt was good range. It will connect as I turn in the driveway. Rather than try various orientations, I just drilled a small hole out the bottom and installed the external antenna. I consider the project a success as I can now work with the door and light from the phone, tablet, fobs or the original physical switches inside the building. With this success behind me, my next project is to upgrade the similar arrangement for a different building. That one has two openers but lights are not involved. This should actually be easy as the sketch is just a modification of the other one. I’m waiting on an ESP32 with external antenna only. I have not been successful in moving the jumper on those boards that allow internal or external antennas. 


   
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(@maxli)
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Joined: 3 years ago
Posts: 36
 

大多数设备现在都需要连接到网络。


   
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Inq
 Inq
(@inq)
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Request for Suggested Reading

I'm doing a project using LoRa - https://forum.dronebotworkshop.com/show-tell/inqbee-lora-battery-powered-remote-sensor-station/   and we're discussing the topic about antennas for them based on Bill's YT tutorial - https://forum.dronebotworkshop.com/2023-videos/lora-long-range-radio-for-iot-arduino-esp32-rpi-pico/

I've seen many topics go by and know there are some active forum members that are hard-core radio enthusiasts.  I'm hoping by posting in here, I might reach some.  

I'd like to learn more about tuning radio antennas than the simple length based on frequency.  I'm currently using the 8.19cm length of wire for the LoRa 915MHz range used in North America.  Bill demonstrates several off-the-shelf antennas and clearly one omni-directional antenna doesn't use this rule of thumb.  It is about an inch in diameter and over a foot long.

@davee is getting me (and others) started on the building blocks for any analysis at - https://forum.dronebotworkshop.com/2023-videos/lora-long-range-radio-for-iot-arduino-esp32-rpi-pico/paged/5/#post-43915 .  He dropped the phrase Antenna Impedance Matching as being important. 

I'm interested in some suggestions or links how best to accomplish this.  Although I'd like a more practical guide, I'm not normally afraid of higher math.  

My first Google search turned up this document  https://abracon.com/uploads/resources/Abracon-White-Paper-Antenna-Impedance-Matching.pdf and I'm trying to go through it now.  One key phrase I found in it describes a Vector Network Analyzer (VNA).  Not having much hope this was an affordable device for an occasional user, I was pleasantly surprised to find even on Amazon they were really dirt cheap compared to oscilloscopes. 

amazon.com/s?k=vector+network+analyzerI'm wondering if you can recommend these (or similar) or are they mere toys meant to capture Noobs like me.

Thank you for your help.

VBR,

Inq

 

3 lines of code = InqPortal = Complete IoT, App, Web Server w/ GUI Admin Client, WiFi Manager, Drag & Drop File Manager, OTA, Performance Metrics, Web Socket Comms, Easy App API, All running on ESP8266...
Even usable on ESP-01S - Quickest Start Guide


   
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Inq
 Inq
(@inq)
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Joined: 2 years ago
Posts: 1900
 

Posted by: @codecage

Although I am an amateur radio operator myself, this question might be better suited to a forum or group of folks that are all about amateur radio.

I got this quote out of the other thread, but I wanted to ping you also about the questions of my previous post.  Would there likely be another forum that you could recommend that would be appropriate to this... and possibly have LoRa people too?

Thanks,

Inq

3 lines of code = InqPortal = Complete IoT, App, Web Server w/ GUI Admin Client, WiFi Manager, Drag & Drop File Manager, OTA, Performance Metrics, Web Socket Comms, Easy App API, All running on ESP8266...
Even usable on ESP-01S - Quickest Start Guide


   
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(@davee)
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Joined: 3 years ago
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Hi @inq,

  I'm watching for any good suggestions from active radio amateurs etc.

My faint recollection from amateurs I knew over half a century ago was that the American Radio Relay League (ARRL) and Radio Society of Great Britain (RSGB) used to publish books on practical aerial design at amateur prices. I never bought any, but glanced at one of two at the time.

Obviously, they will have been orientated towards the amateur frequency bands ... which in those days (in the UK) were mainly in the range 1.8Mhz to 144MHz, although there was some activity around 432 (?) MHz, and possibly higher.  Plus, they were about long distance communications. At that time, there were no legal 'citizen's bands' in the UK; although 'walkie-talkies' could be imported, their use was illegal, and in the same band as radio control. Bands (like WiFi) with no licence required, were non-existent. Hopefully, the books will have been updated since then, but whether they will cover your interests, I have no idea!

I am sure there are some 'professional' books, but their prices are likely to be very unfriendly, and I have never read any of them.

A quick Google of 'radio aerial simulator' showed a few possibilities, but I haven't looked at them.

Depending on your aspirations, this may be interesting and worthwhile or a deep rabbit hole ... your decision!

Best wishes, Dave


   
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Lee G
(@lee-g)
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Joined: 3 years ago
Posts: 67
 

The ARRL does have an Antenna Book which explains antenna theory and design. Of course, it concentrates on the amateur radio bands, but the theory should/would hold for any radio band. The book is on the expensive side ($80) depending on where you get it. I believe it’s also available as an e-book. If you’re interested you can check it out on their website arrl.org.

Lee

WB5DTU


   
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Inq
 Inq
(@inq)
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Posted by: @lee-g

The ARRL does have an Antenna Book which explains antenna theory and design. Of course, it concentrates on the amateur radio bands, but the theory should/would hold for any radio band. The book is on the expensive side ($80) depending on where you get it. I believe it’s also available as an e-book. If you’re interested you can check it out on their website arrl.org.

Lee

WB5DTU

It looks like its available used on Abe for around $10, but didn't see revision numbers, but I imagine the theory hasn't changed all that much.  🤣  Although, I might have to look into the E-book.  I'd like to be able to do the search.  

Thanks.

 

3 lines of code = InqPortal = Complete IoT, App, Web Server w/ GUI Admin Client, WiFi Manager, Drag & Drop File Manager, OTA, Performance Metrics, Web Socket Comms, Easy App API, All running on ESP8266...
Even usable on ESP-01S - Quickest Start Guide


   
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 Inq
(@inq)
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Posted by: @davee

Depending on your aspirations, this may be interesting and worthwhile or a deep rabbit hole ... your decision!

Yes, that's a definite concern.  If someone expert said going from proper length wire to a perfectly tuned antenna would only double my range, I probably wouldn't spend the days of reading and studying.  If it could be truly impressive like 10x, I probably would.  I'd like to reach the farm at about 8 miles.  But living in the mountains probably kills that dream anyway.  Plus, I'd need to get a baseline of what it does with the simple wire antenna.  If it doesn't even get out of my cove, it wouldn't be all that advisable. 

FROM

CliSvr

TO

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Not to mention, I could always just buy the big antenna.  But what would the fun be in that? 😆 

3 lines of code = InqPortal = Complete IoT, App, Web Server w/ GUI Admin Client, WiFi Manager, Drag & Drop File Manager, OTA, Performance Metrics, Web Socket Comms, Easy App API, All running on ESP8266...
Even usable on ESP-01S - Quickest Start Guide


   
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Ron
 Ron
(@zander)
Father of a miniature Wookie
Joined: 4 years ago
Posts: 7334
 

@inq Have a look at these modules https://amz.run/7KiT I will put these together shortly so I can test the range in order to see if I can reach my garden.

Notice the size of the antenna, it may be more than a simple straight wire since some parts of the antenna are fatter than others.

I am on the road, but when I get back I will try to put it together in the next two days and report back.

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
My personal scorecard is now 1 PC hardware fix (circa 1982), 1 open source fix (at age 82), and 2 zero day bugs in a major OS.


   
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(@davee)
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Joined: 3 years ago
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Hi Inq,

 If someone expert said going from proper length wire to a perfectly tuned antenna would only double my range, I probably wouldn't spend the days of reading and studying.

Tuning the antenna without appropriate test gear is unlikely to be that rewarding. I haven't seen any ARRL/RSGB books for over half a century, but radio amateurs usually used to start with transmitters in the Watts+ power range, so homebrew and commercial meters for Standing Wave Ratio (SWR), and antenna tuning units (ATU) etc. had a reasonable to high voltage to sense. They typically used a 60W or 100W filament bulb as a dummy load to do the adjustments, etc. The transmitters you are looking at are orders of magnitude lower in power, and the frequencies are higher, so you may have some challenges, although there are some fairly cheap, but not necessarily accurate instruments on the Chinese market! (I have only done occasional window shopping, out of curiosity, as I'm not in that game.)

However, subject to regulatory, etc. limitations, you may be able to get a higher gain, directional aerial (possibly even homebrew) to increase the effective radiated power heading in the required direction, as against spreading the energy widely, mainly in unnecessary directions.

Best wishes, Dave


   
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Inq
 Inq
(@inq)
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Posted by: @zander

@inq Have a look at these modules https://amz.run/7KiT I will put these together shortly so I can test the range in order to see if I can reach my garden.

Notice the size of the antenna, it may be more than a simple straight wire since some parts of the antenna are fatter than others.

I am on the road, but when I get back I will try to put it together in the next two days and report back.

I can see it might be nice to have a little screen out at the garden (or bee hive in my case) but I think I'd be torn how to keep it both visible and weather proof.  I just bought the cheaper, base units.  

image

 They are more of a PITA as they're not pin compatible with a breadboard, but they are pin compatible with the bare ESP8266-12E.  My ability to solder in such tiny spaces is being tested. 

Besides, with my SpaceX design philosophy of build-smoke-rebuild... required me to buy 5 instead of 2.  😆 It's cheaper this way.  

VBR,

Inq

P.S. - It just has the wire antennas, but my test client/server are talking and I've made the server portable so I can see the results while I walk around the property and if all goes well, drive down the road and get a maximum range in my area.  I'll be testing tomorrow.  I'll report back in my project thread.

 

3 lines of code = InqPortal = Complete IoT, App, Web Server w/ GUI Admin Client, WiFi Manager, Drag & Drop File Manager, OTA, Performance Metrics, Web Socket Comms, Easy App API, All running on ESP8266...
Even usable on ESP-01S - Quickest Start Guide


   
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Inq
 Inq
(@inq)
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Posted by: @davee

However, subject to regulatory, etc. limitations, you may be able to get a higher gain, directional aerial (possibly even homebrew) to increase the effective radiated power heading in the required direction, as against spreading the energy widely, mainly in unnecessary directions.

I'll be testing the base-line wire antennas tomorrow.  If they only cover my yard (200 yards) that'll be good enough for my first goal, but will squelch my drive that no matter how perfect I match and tune everything, I'm unlikely to extend that to 8 miles.  If I can end up driving 4 miles and still get a signal (with these simple wires) it might be worth pursuing something more exotic.  Either way, I'm still interested in understanding the theory we're exploring in the other thread.

VBR,

Inq

P.S. - I now live in an area of the country where the homebrew is Moonshine and where during the Prohibition "The Man" was not welcome and often shot at.  We retired back to this area as my wife's family is from here. Her great-grand-father made and boot-legged the Shine.  They even bread a special strain of corn specialized for making corn-whiskey.  It has been genetically tested and is now recognized as a distinct, named breed.  If I tune a directional antenna that can reach into the mountains for 8 miles and it does micro-bursts of data at huge, maybe random, intervals, it might be difficult for the Man to find the radios.  Now, that Moonshine is kind-of legal to make and/or sell, we have to find something to rebel with.  😆 

3 lines of code = InqPortal = Complete IoT, App, Web Server w/ GUI Admin Client, WiFi Manager, Drag & Drop File Manager, OTA, Performance Metrics, Web Socket Comms, Easy App API, All running on ESP8266...
Even usable on ESP-01S - Quickest Start Guide


   
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Ron
 Ron
(@zander)
Father of a miniature Wookie
Joined: 4 years ago
Posts: 7334
 

@inq I also have some of the base units. I also have on backorder the carrier board to convert the pin spacing to normal. I think they are called flexy pins and are due in this Dec at Digikey.

Screenshot 2023 11 18 at 08.23.52

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
My personal scorecard is now 1 PC hardware fix (circa 1982), 1 open source fix (at age 82), and 2 zero day bugs in a major OS.


   
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Ron
 Ron
(@zander)
Father of a miniature Wookie
Joined: 4 years ago
Posts: 7334
 

@inq The LORA work best with line of sight and that can go multiple 10's of miles. As far as antenna design, if you can remember the CB radio days, you will recall very long whip antennas, some going 6 or 10 ft. They worked due to 'goodies' in the base of the antenna. I also see them on forestry and military vehicles but even longer so they travel with them bent over and secured to the vehicle somewhere. I have no idea of the freq's involved in any of that but as someone said earlier, 1/2 wave is 'best' but 1/4 is only a little less and packaging that size may be easier. Look closely at the units I posted, that is NOT a simple wire, looks a lot like a transformer since it is thick at base, thin on middle, thick at the tip. I want to get my test done ASAP, but this trip was to see a puppy which we bring home next weekend so I could be very distracted. Sorry, puppies are way cuter than you mugs.

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
My personal scorecard is now 1 PC hardware fix (circa 1982), 1 open source fix (at age 82), and 2 zero day bugs in a major OS.


   
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Inq
 Inq
(@inq)
Member
Joined: 2 years ago
Posts: 1900
 

Posted by: @zander

Sorry, puppies are way cuter than you mugs.

No doubt there - Unconditional love from a puppy is priceless.  

3 lines of code = InqPortal = Complete IoT, App, Web Server w/ GUI Admin Client, WiFi Manager, Drag & Drop File Manager, OTA, Performance Metrics, Web Socket Comms, Easy App API, All running on ESP8266...
Even usable on ESP-01S - Quickest Start Guide


   
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