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RF M4 315MHZ Momentary Receiver range increase
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Please be positive and constructive with your questions and comments.

RF M4 315MHZ Momentary Receiver range increase

by chriswei on Tue Sep 14, 2021 11:07 pm

Hi -

I'm using one of the RF M4 315MHZ Momentary Receivers and the associated 4-button keyfob. I'm getting around 10-foot range with this setup, powering the receiver board with 3.3V from an ItsyBitsy M4 Express instead of 5V to avoid having to drop the pin voltage from the receiver to the ItsyBitsy with a voltage divider.

Is there a way to increase the range of the receiver/keyfob combination? Would powering the receiver board with its 'expected' 5V increase the range?

Thank you!

- Chris

chriswei
 
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Re: RF M4 315MHZ Momentary Receiver range increase

by adafruit_support_mike on Sun Sep 19, 2021 10:14 pm

Transmission power is proportional to the transmitter's working voltage, so yes, running it at 3.3V will reduce its range a bit.

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Re: RF M4 315MHZ Momentary Receiver range increase

by sj_remington on Sun Sep 19, 2021 10:22 pm

Better antennas on RX, TX or both will certainly help. A decent antenna can be as simple as a 1/4 wavelength piece of straight wire, or about 23 cm for 315 MHz.

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Re: RF M4 315MHZ Momentary Receiver range increase

by chriswei on Sun Sep 19, 2021 10:25 pm

Thanks for the reply!

I was finally able to run some experiments, powering the RF board with 5V from the ItsyBitsy M4's USB pin and using a voltage divider to drop the RF board's output pin voltage under 3.3V, and I saw a definite improvement in range.

chriswei
 
Posts: 11
Joined: Tue Jan 17, 2012 4:38 pm

Please be positive and constructive with your questions and comments.