Overview

SSB Electronic AS-3000A Mast Mount Antenna System Switch

SSB Electronic AS-3000A Mast Mount Antenna System Switch is an integral part of a low-loss preamplifier and power amplifier control for two-way VHF, UHF and SHF stations. Covering the entire range from DC to 3 GHz, two high quality SPDT coaxial relays, housed in their weather- and UV-resistant enclosure, provide excellent power handling and port isolation with minimal insertion loss. The solid aluminum chassis base incorporates a mounting bracket for a 1.5 to 2.4 in. mast clamp, with six downward facing Type-N female connectors for the antenna, a mast mounted preamp, a power amplifier and the station. A single Type-F connector provides DC out for the preamplifier and a 4-pin DIN with mating connector is used for direct DC control of the relays, typically with a sequencer. User supplied shielded control and power cables are recommended to prevent RF induced false keying.

The AS-3000A supports the use of short lengths of coaxial cable for mast mounted equipment to dramatically reduce losses. Coaxial lines used in this type of system should be calculated and tailored so that they do not cause an impedance transformation.

The connection of the transmitting equipment to the normally closed (NC) side of the AS-3000A relays allows the safe handling of high RF power without risk to the mast mounted preamp or LNA. Voltage is required to engage the normally open (NO) side of the relays for connection of the receive only preamplifier or LNA to the antenna. Removal of the voltage, or if power is lost, allows safe transmission without worry of equipment damage from transmitted RF, and keeps the preamplifier offline when the station is not used, for charge and pulse protection.

See the linked documentation for detailed diagrams of system connections which typically require a sequencer, such as the SSB Electronic DCW2004B (ESB-1025), and an LNA, Mast Mount or separately enclosed.

Specifications of the AS-3000A Mast Mount Antenna System Switch (ESB-5058):

Frequency range: DC – 3000 MHz
Switch positions: 2
Insertion loss per relay, typ.:
0.01 dB / 150 MHz
0.02 dB / 500 MHz
0.025 dB / 1000 MHz
0.03 dB / 2000 MHz
< 0.1 dB / 3000 MHz
Isolation: >60 dB / 2,5 GHz
VSWR: <1.2 : 1
RF Power Handling, by band:
1000 W/2m;
800 W/70cm;
500 W/23cm;
250 W/13cm
RF Connectors: Type-N female
LNA DC Connection: Type-F female
Direct DC Control Input: 4-pin DIN (mating connector provided)
Switching Voltage: 13.8 VDC @ 650mA , max.

Documentation

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