Product Description:
The SP 400 is a selective receive preamplifier with transmit / receive switching. It provides adjustable gain, low noise and good large-signal response. At low transmission power, the transmission / reception switching can be realized by means of a built-in VOX circuit.
This amplifier is built with a GaAs MMIC of the latest technology on high quality microwave substrate in SMD technology.
The band pass at the output of the amplifier ensures good band selection, so that all signals that lie outside the usefulband are effectively suppressed. This amplifier has a UVresistant plastic housing that protects against splash water and galvanized mast clamps with stainless steel screws for attachment to the antenna mast.
Connection Notes:
The amplifier is installed in the vicinity of the antenna system with the sockets facing downwards by means of the supplied mast clamps on the antenna mast. The ANT jack is connected to the antenna by a short low attenuation coaxial cable. The TRX socket is connected via a coaxial cable to the antenna socket of the transceiver, which outputs a LNA remote power supply. For transceivers that do not have an LNA power supply, a pre connected bias-tee can be used for the remote feed of the amplifier.
In this case, the amplifier is fed by the DC-switch e.g. DCC 5000pro permanently. The transmit- / receive switching is done with the HF VOX circuitry when the transmit signal is output from the transceiver. In the case of a direct supply via the UHF socket, a shielded supply line must be used in order to prevent the transmission of the signal into the station power supply and further into the transceiver. At high
transmission powers in installations with a power amplifier, the transmit- / receive switching must be realized with a sequencer e.g. DCW 2004 B. In order not to degrade the high signal strength of the receiver, it is advisable to switch off the internal preamplifier of the transceiver when using the mast preamplifier. If it can not be switched off, then the gain of the SP 400 can be infinitely reduced if necessary by up to 10 dB. The adjusting screw for this is located under the plastic hood in a hole in the tinplate housing of the preamplifier.
Technical Data:
- Frequency Range: UHF-Female 70 -71 MHz
- Gain, Variable: 9 -18 dB
- Noise Figure, Typ.: 0,7 dB
- OIP3: 25 dBm
- Max. Switching Capacity With HF-VOX: 100 W
- Transferable Power When Using A Sequencer: 750 W PEP, 400 W / CW, FM, WSJT
- Insertion Loss: 0.03 dB
- Connection Standard: N-Female
- DC Input Local: UHF-Female
- Remote Feed: N-Female
- Operating Voltage: 12V -14V
- Current Consumption Typ.: 260 mA
- Mast Diameter: Max. 58 mm
- Switching Time (TX->RX): 0.50 sec.
- Switching Time (RX->TX): UHF-Female 0.02 sec.
