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I want to replace the antenna on my toy quadcopter with a better one, to improve reception.

On toy quadcopters the antenna is just a simple wire soldered to the quadcopter circuit board (with no shielding nor ground connection, just like this board for example: https://www.eachine.com/Eachine-E016...de-p-1378.html ).

On the othe hand, the antenna that I want to put is a proper 2.4ghz dipole antennas, with a shielded coaxial cable.. ( like this one: https://shop.prodrone.pl/en_US/p/Goo...nna-2.4Ghz/163 )

from my understanding, besides connecting the active element to the circuit biard, I should also connect the shielding of the coax to the electrical ground of the board.

My question is: how do I find a ground connection on those toy boards ? Is it correct if I connect the coax shielding directly to the negative cable of the battery/power supply ? ( I ask this because I have read that all the ground pins / the ground plane of the PCB flows back to the negative connection of the battery ).

thx for any pointer and/or correction! I am very ignorant in electronics, but I hope I managed to make sense..


PS: I know that there is also this question that is fairly similar: How to ground wi-fi antenna outer wire on circuit board connector? But it doesnt answer the following points of my questions: - how do I find a ground connection on those toy boards ? (what is the general procedure to find a ground pin ?) - can I simply connect the shielding if the coax to the negative battery cable and assume that it is grounded that way ?

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  • \$\begingroup\$ Coax cable is probably not going to help you. You can consider putting an opposite quarter wave on the nearest point of ground plane to the antenna or its RF matching circuit. But the useful visual range of such a tiny aircraft is fairly limited anyway, and beyond that your real issue may be the infamous XN297 chip or whatever combo radio/mcu they are using these days. \$\endgroup\$ – Chris Stratton Feb 26 at 4:11
  • \$\begingroup\$ @Chris Stratton I want to add a small 25mw FPV camera, and I want to make sure that the video signal starts to break before than the control signal, so I know when to turn back.. the radio/MCU is a TLSR8368/TLSR8568, on the datasheet it claims an Rx sensitivity of -97 dBm wiki.telink-semi.cn/doc/ds/… \$\endgroup\$ – fruitbat Feb 26 at 13:04
  • \$\begingroup\$ You'd be better off replacing the board with a better one - they are $10-20 items, and those that have been reverse engineered open up using a real hobby grade transmitter. \$\endgroup\$ – Chris Stratton Feb 26 at 16:06
  • \$\begingroup\$ @Chris Stratton true, a hobby grade transmitter coupled with a better board would give much better range and maybe even RSSI telemetry. I had considered that option but a good transmitter like that is at least 100$ and at the moment beyond my budget. I received the FPV equipment as a gift and I'm trying to couple it with the quad that I already have on a very tight budget :) \$\endgroup\$ – fruitbat Feb 27 at 15:20

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