DX Engineering NCC-2 Phase system for reception
Better reception due to interference suppression
The NCC-2 is used for interference suppression during reception on long, medium and short wave. It combats local interference from switching power supplies or plasma TVs as well as interference from distant stations. This is achieved by phase compensation of the signals from two antennas. These two antennas can be the main antenna of the station and an auxiliary antenna, or two similar receiving antennas. Active receiving antennas can also be used. Each receiving branch of these two antennas is equipped with its own attenuator. A balance control ensures precise level adjustment in front of the phase shifter. The phase position itself is adjusted via a large and precisely tunable control, thus ensuring very effective suppression of almost any interference. This operating principle has been known for quite some time, but the NCC-2 takes it to a whole new level. This is expressed among other things by the exact level adjustment, on the other hand by a sophisticated PTT switching which reliably prevents a transmission without or with wrong antenna. Multiple connection possibilities for each antenna channel (PL, BNC, F-socket) allow a high flexibility in the selection of antennas. The possibilities of the NCC-2 are rounded off by optional modules for preamplifier, overvoltage protection and impedance matching.
The NCC-2's ability to suppress interference often makes the difference between a successful QSO and an 'inaudible' one. By 'zeroing' the interference with the phase shifter, the useful signal is often much better audible, whether it is a rare amateur radio station or the distant DX of a shortwave listener (SWL). If two similar receiving antennas are used, the NCC-2 can achieve a directivity similar to that of an array. Here either the signal of both antennas is added and thus amplified, or the signals are subtracted by phase reversal. The effect is the effective amplification of the useful signal or the suppression of a disturbance. It does not matter whether the interference is generated locally, e.g. by the bright power supply of an LED light, or comes from a distant station on the same frequency.
The expandability of the NCC-2 with various options ensures that this device can be perfectly adapted to your own station. Three slots are available for each of the two antenna channels. For example, you can use a preamplifier switchable from the front panel, or a protection circuit against extreme signal levels, or impedance matching for inexpensive and low-loss 75 Ohm antenna cables. For active antennas, a supply voltage can be connected to each connection socket (phantom power). The usable frequency range is 500 kHz to 15 MHz, with lower efficiency from 300 kHz to 30 MHz. For operation, the NCC-2 requires a voltage of 13.8V at approx. 2A current consumption. A plug for the voltage connection is included.