Do you have a question about the RM Italy VLA 200 and is the answer not in the manual?
The VLA 200 is a VHF linear amplifier designed to enhance radio frequency signals. It is certified to comply with the provisions of the European Communities' EMC Directive 89/336/EEC, as confirmed by RM Costruzioni elettroniche in accordance with European Telecommunications Standards ETS 300 684-300 339, dated December 1995.
The VLA 200 serves as a VHF linear amplifier, capable of amplifying signals within the 144-148 MHz frequency range. It features an electronic switch for operation and includes protection mechanisms against polarity inversion and excessive Standing Wave Ratio (SWR). The amplifier can operate in both FM and SSB modes, making it versatile for various communication needs. It also incorporates a preamplifier with an ON/OFF switch to boost weak incoming signals.
The device includes several indicators:
For optimal performance and longevity, the VLA 200 should be positioned to ensure adequate airflow to its heat radiator. Power supply cables should be as short as possible, not exceeding 3 meters, and ideally connected directly to the battery with a minimum cross-section of 4 mm².
The 50 Ω antenna cable should be of high quality, suitable for the operating frequency and power. Its length should be minimized to prevent significant attenuation during transmission, which can lead to power loss and a degraded signal-to-noise ratio during reception. The antenna used should be capable of handling the amplifier's power and maintain an SWR not exceeding 1.5 at maximum power. High-quality Teflon connectors are recommended for all connections.
The connection between the transceiver (RTX) and the amplifier should be made with a 50 Ω cable, with a recommended length of approximately ½λ x 0.66. The VLA 200 is equipped with a PTT (Push-To-Talk) command that allows direct RX-TX switching from the transceiver, which is particularly useful for SSB, CW, and Packet modes as it significantly reduces switching times. When using this PTT connection, the mode switch should be set to FM.
It is advised not to remain in transmission for extended periods without reasonable cooling intervals for the transistors. For base station use, it is recommended to use a battery with a buffer charger.
The device is protected against polarity inversion and excessive SWR. If the protection state indicator (Warning LED) illuminates, it signifies an intervention of the protection circuit due to an excessive SWR level. To restore the amplifier's functionality, turn the amplifier OFF and then ON again after resolving the cause of the protection activation (e.g., correcting the antenna SWR).
The VLA 200 comes with a 24-month warranty from the date of purchase. However, it is crucial to note that the warranty does not cover final transistors or aesthetic parts, and it is void if the instructions are not observed. The manufacturer emphasizes that the use of linear amplifiers is subject to specific laws, and users are responsible for knowing and complying with these regulations. The manufacturer disclaims any responsibility for incorrect use.
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