433mhz Antennas Diy

I understand, English is not my first language as well, feel free to ask me anything I will try to help as best as I can.

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You as well :slight_smile: , btw your written English is really good :+1:

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It has, but I can still tell when a translator is being used Lol

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Very nice build, nice solution for GPS antenna, is with build in LNA?
How did you power GPS LNA?
Why use RG174?

GP = 0,0 gain
Low SWR its match 50 Ohms, not show about antenna radiation pattern :wink:

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I dont know if the PCB GPS ant connector have 3 - 5 Volt BIAS-T to power de GPS LNA. Mabe the programmers know if needed to turn ON the BIAS-T than you have 38 dB extra.

The uBlox GPS on the t-beam is capable of supplying a 3v bias, but it seems from what others have said that itā€™s pretty random whether itā€™s enabled or not when we receive them. Some people have receive t-beamā€™s with the bias voltage disabled, some with it enabled.

I donā€™t know enough about the t-beam yet to know if weā€™re able to pass commands direct to the gps chip via serial. If we could pass commands to the chipā€™s serial line the bias could be enabled (if currently disabled).

If itā€™s something that IS do-able through the meshtastic firmware it might be nice if a checkbox enable / disable option was added to the admin settings interface.

Ric

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I am looking to build the most efficient receiver antenna for my 433 MHz RC car. I would like to build my own antenna and Iā€™m interested in your designs here.

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Kool, Feel free to duplicate any of the designs, It would be best to have a VNA or NVNa to tune, for that application A loaded Dipole or whip should so the trick all you need to do is tune it.

Would this work well in a 433mhz RC car as a receiver antenna for best distance? Is this a 5/8 wave antenna or 1.25 wave? Thanks.

There are several designs that you could use, But I think a 1/2 Wave Dipole would do the trick, your RC car may have a long antenna though.