HC-12 Antenna Stuff

techElder

Well-known member
#1
Gathered this from some of the posts by others under HC-12 or HC-11.

Based on formula below at 433 MHz. Ratio between a 1/4 wave and a 5/8 wave is 2.5.

UHF antenna of 1/4 wavelength made with solid wire: length cut to 6.82" (173.2mm) cut long and trim for best range.

UHF antenna of 1/2 wavelength made with solid wire: length cut to 13.64" (346.4mm) cut long and trim for best range.

UHF antenna of 5/8 wavelength made with solid wire: length cut to 17.04" (433mm) cut long and trim for best range.

Formula to calculate antenna length

Code:
Antenna Length (mm) = 75,000 divided by the Frequency (MHz)
Example: 75,000 / 433 = 173.21 mm (6.819")

A 1/4 wave antenna mounted on a metallic base is going to be a very good antenna. I have made one from connector and cable parts that fit an HC-12. The key words on the cable/connector combination is "U.FL(IPEX/IPX)" and "SMA Female."

RF Connector Pigtail Cable SMA Female Bulkhead to Ufl./ipx Extension Cable 1.13 Cable 5cm

SMA Male Straight Crimp Connector

The theoretical 1/4 antenna operation.

https://upload.wikimedia.org/wikipedia/commons/c/ca/A6-3EN.jpg
 
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