300-346 MHz Vertical antennas A4 ALT : Radial :

Electrical specifications

Model	A4 ALT (L)	A4 ALT (H)
Operating frequency band, MHz	297-310	335-346
VSWR, not more than	1.5
Gain, dBi	8	9
Sector in vertical plane , -3dB	24°	20°
Impedance, Ohm	50
Max. power input, W	200
Lightning protection	yes
Adjustable	no need

Mechanical specifications

Model	A4 ALT (L)	A4 ALT (H)
Weight, kg	not more 5
Height/Length, mm	4120
Mast diametr, mm	50-110
Radome	fiberglass
Rated wind velocity, m/s	40
Wind loading area, m²	0.246
Load of side wind 40 m/s, H	180
Temperature range, °C	from -50 to +50
Connector	N-female, (7/16 DIN-optional)

Antenna A4 ALT represents collinear construction with four active components, providing perfect circular pattern at high gain (9 dB) and wide operating frequency band.
Radioparent weather-proof radome is made on the basis of fiberglass material. Radome has polished fiberglass coating, which protects from ultraviolet radiation and icing.
Antenna has DC grounding and has no need in additional tuning.
There were designed two antennas for use as transmitting and receiving antennas in MPT 1327 communication systems: A4 ALT(L), with 305 MHz center and A4 ALT(H) with 340 MHz center.

A4 ALT(L, H) E-plane pattern

VSWR diagram, A4 ALT(L)

300-346 MHz Vertical antennas A4 ALT

Electrical specifications

Mechanical specifications

A4 ALT(L, H) E-plane pattern

VSWR diagram, A4 ALT(L)

VSWR diagram, A4 ALT(H)