Improve range signal for 433MHz crystal oscillator in PCB

Thread Starter

Alanamy2613

Joined Apr 18, 2024
3
Hello. Im newbie in pcb design. My problem is my prototype can't perform well after 50m. I want to improve the range of the signal(can go to 100m or more) (in building not open area). No outer antenna. All is inside. Here my prototype picture. if there something wrong and can suggest best design? im using LR433T2. or any components that suit for my project. Thanks in advance
 

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Thread Starter

Alanamy2613

Joined Apr 18, 2024
3
Hello. Im newbie in pcb design. My problem is my prototype can't perform well after 50m. I want to improve the range of the signal(can go to 100m or more) (in building not open area). No outer antenna. All is inside. Here my prototype picture. if there something wrong and can suggest best design? im using LR433T2. or any components that suit for my project. Thanks in advance
Screenshot 2024-04-26 163516.pngMy schematic
 

Ya’akov

Joined Jan 27, 2019
9,267
Welcome to AAC.

Unfortunately, I don’t know of anywhere in the world where operating that device would be legal. Be aware that you could potentially cause a lot of interference with legitimate devices operating in that band and really shouldn’t build it at all.

Sorry for the differently helpful answer than you hoped for.
 

Thread Starter

Alanamy2613

Joined Apr 18, 2024
3
Welcome to AAC.

Unfortunately, I don’t know of anywhere in the world where operating that device would be legal. Be aware that you could potentially cause a lot of interference with legitimate devices operating in that band and really shouldn’t build it at all.

Sorry for the differently helpful answer than you hoped for.
Thank you for your attention. Basically im from asian country. its legal and my device basically for autogate remote control.
 

Ya’akov

Joined Jan 27, 2019
9,267
Thank you for your attention. Basically im from asian country. its legal and my device basically for autogate remote control.
If I am correct in guessing you are in Malaysia, then you should read the attached document from the MCMC. In particular, there are these paragraphs:

1714123893967.png
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from CLASS ASSIGNMENT NO. 1 OF 2017, page 8

A remote controlled device falls under the twelfth schedule and has no exemption from the certification requirements. So, unfortunately, so far as I can tell it is not legal. This is no surprise as the 433MHz ISM band is subject to international treaties and all countries I know about have very similar regulations concerning unlicensed devices.

In Malaysia, it is a little different to the extent no spectrum is considered “unlicensed” and instead users are granted a “Class Assignment” to operate these devices under MCMC rules and regulations—but the effect is the same. One technical difference is that while most jurisdictions allow 100mW in the 433MHz band, the MCMC limits operation to 50mW.

So, even if you did spend the time and money to get your device certified—or uncertified operation was allowed—it is unlikely that your design constraints of 100m indoor operation with no external antenna can be met.
 

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MisterBill2

Joined Jan 23, 2018
19,474
Interesting about the laws in that section of the world. A few years back I sent some 700 MHZ band wireless microphones to a missionary located in "rural Thailand". The FCC has no control in that part of the world, and probably that band segment has not yet been taken over by communication interests. Now I wonder.
 

DickCappels

Joined Aug 21, 2008
10,247
Thailand is particularly interested in how the spectrum is used. My basic policy is: If they can't hear your transmitter, how would that be a problem? That's all I am going to say for now.
 

MisterBill2

Joined Jan 23, 2018
19,474
Thailand is particularly interested in how the spectrum is used. My basic policy is: If they can't hear your transmitter, how would that be a problem? That's all I am going to say for now.
It has been over three years and no reports of any complaints. The claimed rang was 200 feet. The area is fairly rural.
 
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