Vectronics VEC-884 - Manual (Page 59)

VEC-884 Owner's Manual
Filter Description 5-7
SSB Filter [5]
Use: All Voice modes, FSK, CW Filter.
Passes medium to wide frequency width.
The SSB filter is a band-pass filter with adjustable center frequency and
bandwidth. The center frequency (fc) is adjusted with the Tunable Filters left
knob in a range of 600 Hz to 1700 Hz. The Tunable Filters right knob adjusts
the bandwidth (BW) from 1000 Hz to 2500 Hz. The actual filter response is
limited internally to a minimum of 175 Hz.
While some voice transmissions may be understandable with only 1000 Hz of
bandwidth if the center frequency is properly adjusted, the majority of stations
will be copied best with the controls nearly centered. The optimum center
frequency and bandwidth setting will be determined by the transmitting
operator's voice, the transmitter's response, the receiver's response, any
noise or QRM, and/or the receiving operator's hearing.
The operator may prefer to monitor himself/herself in the transmit mode.
Refer to the section called Passing Sidetone on page 2-5.
RTTY Filter [6]
Use: RTTY, FSK.
Passes high frequency tones with narrow frequency width.
The RTTY filter is factory pre-set for best performance with standard 2125-
2295 Hz mark-space frequencies (170 Hz shift), 45 baud RTTY signals. This
filter can also be programmed to one of several different mark-space
frequencies and/or baud rates. This procedure is detailed on page 4-11.
Under special conditions the operator may wish to use one of the adjustable
band-pass filters in place of the RTTY filter.
HF PACKET Filter [7]
Use: Packet, Wide RTTY, FSK.
Passes high frequency tones with medium frequency width.
The HF Packet filter is factory pre-set for best performance with standard
2125-2295 Hz mark-space frequencies (170 Hz shift), 300 baud HF Packet
signals. This filter can also be programmed to one of several different mark-
space frequencies and/or baud rates. This procedure is detailed on page 4-
11. Under special conditions the operator may wish to use one of the
adjustable band-pass filters in place of the HF Packet filter.