Note
The VEC-884 is essentially a rebranded version of the MFJ-784B. When MFJ acquired Vectronics in the late 90s, many products were cross-branded.
The VEC-884 is a highly selective, tunable audio filter that utilizes 16-bit DSP technology. It is designed to improve signal clarity by digitally reducing or eliminating noise and interference. The unit operates by converting analog audio from a receiver into digital data, processing it through various filter algorithms, and then converting it back to audio for output to speakers or headphones.
Features
– Diverse Filtering Options: Includes 5 tunable filters (LR/HR, Band-pass, Double band-pass, CW, and SSB) and 5 pre-set data filters for modes like RTTY, HF Packet, and AMTOR.
– Notch Filtering: Features a manual notch filter that can manually attenuate two tones and an automatic notch filter capable of eliminating up to four changing tones or heterodynes.
– Adaptive Noise Reduction: Provides a manually adjustable noise reduction filter that can reduce random noise by up to 20 dB.
– Memory Locations: Allows users to save up to ten favorite filter – Automatic Gain Control (AGC): Includes a front-panel button to enable AGC, helping to maintain consistent audio levels.
– Sidetone Management: Offers two methods for passing a transmitter's sidetone through the filter, including a dedicated internal CW sidetone filter.
– Direct Audio Bypass: Features a hardware bypass that connects input ports directly to outputs when the power is turned off.
Specifications
– Processor: Analog Devices ADSP-2105, 16-bit data width, 12 MHz clock speed.
– Audio Output Power: Approximately 2.5 watts into a 6 ohm load.
– Frequency Response: 250 Hz to 3100 Hz (-3 dB).
– Operating Voltage: 10–16 VDC (12 VDC nominal).
– Current Consumption: Between 175 mA and 500 mA (peak).
– Input Impedance: 10 K ohms nominal.
– Input Signal Range:1 to 2.8 volts P-P at maximum sensitivity.
– Filtered Audio Out: Approximately 1.5 volts P-P at 600 ohms.
– Filter Attenuation: Typically 47 dB to 57 dB depending on the filter type.
– Digital Processing Delay: 23 mS.
