Simple two -band antennas for radio amateur ranges 144 and 433 MHz

June

2024

Simple two -band antennas for radio amateur ranges 144 and 433 MHz

антенны, укв

18 June 2024 10:55

The dual-band dipole antennas - 144 and 433 MHz - for work through VHF-repeaters (gain 0 dbd / 3 dbd).

Previously (10 years ago) I was engaged in the calculation of the Antennes "Open Sleeve", but the hard drive with antennas models failed. Recently, I restored the HDD in the service and begin to lay out the models of antennas from it, accompanying the drawings.

Antenna No. 1 - two -band dipole 144/433 for a cable 75 Ohms

Power supply in the central dipole of the cable 75 Ohms.

Dimensions for a tube with a diameter of 8 mm (say diameter from 4 to 10 mm):

Element	A	S1	S2
Position, mm	0	43	-43
Length, mm	980	328	328

Coordination with a 75 Ohms cable in the range of 144 MHz SWR <1.2, in the range of 433 MHz <1.2.

Antenna No. 2 - two -band dipole 144/433 for a cable 50 Ohms

Antenna split dipole 2-band 144/433 for a cable 50 Ohms.
Power in the section of the central dipole.

Dimensions for a tube with a diameter of 8 mm (say diameter from 4 to 10 mm):

Element	A	S1	S2
Position, mm	0	31	-31
Length, mm	968	316	316

SWR in ranges 144 and 433 MHz (cable 50 Ohms):

Coordination with a cable 50 Ohms in the range of 144 MHz SWR <1.5, in the range of 433 MHz <1.3.

Strengthening in the range of 435 MHz is 5.4 dbi (or 3 dbd):

Antenna No. 3 - Simplified two -band dipole 144 /433 MHz (50 Ohms) **

Further simplification of the "Open Sleeve" antenna is the exclusion of the second driven element. Optimization leads to the same parameters of the SWR, but the orientation diagram in the range of 433 MHz is not circular, but is extended towards the short element.

Industrial dual-band antenna 144/433 MHz