The Models
3340 and
3342
illustrated in Figure 1, are
variable, electronic Filters with digitally tuned cutoff
frequencies over the range from 0. 001 Hz to 99. 9 kHz.
The passband gain is unity (0 db) or 10 (20 db), with
attenuation rates of 48 db per octave (Model(
3340) or 96 db
per octave (Model 3342} outside the passband. Maximum
attenuation is greater than 80 db, and the output hum and
noise is less than 500 microvolts. The Model
3340 can
function as either a High-Pass or Low-Pass
Filter. In the
High-Pass mode of operation the maximum input signal isi
plus or minus 7 volts peak in the 0 db gain position, plus
or minus :0. 7 volts peak in the 20 db gain position, and
the upper 3 db point occurs at approximately 1 MHz. In the
Low-Pass mode the
Filter is direct-coupled, and the combined
ac plus dc input signal should not exceed 7 volts peak in
the 0 db gain position and 0, 7 volts peak in the 20 db gain
position. The models
3341 and
3343 are identical to the 3340
and
3342
respectfully, except for the elimination of the
lowest band (. 001}. The Model
3342 consists of two of the
Model
3340 mounted in a single cabinet isolated from each
other with independent power supplies, and input and output
connectors. ;When these two
Filter channels are switched to
the same mode of operation and connected in series with both
channels set to the same cutoff frequency, the Model 3342
will function as a High-Pass or Low-Pass
Filter with an
attenuation rate of 96 db per octave. If the two channels
are connected in series, and one channel is operated in the
Low- Pass mode and the other channel in the High-Pass mode,
the Model
3342 will function as a Band-Pass
Filter with an
attenuation rate of 48 db per octave outside the pass-band.
When the two channels are connected in parallel, as
described in Section 2. 3. 2. 3, the Model
3342 will
function as either a Band-Reject
Filter with cutoff
frequency limits from 0. 001 Hz to 99. 9 kHz or provide a
null at any frequency between 0. 003 Hz and 30 kHz.
The
Filter has a maximally flat (Butterworth} characteristic
when the FUNCTION switch(s} is in the Low-Pass MAX FLAT
position. For pulse-type wave-forms this switch should be in
the Low-Pass RC position, optimum for transient-free
filtering. The term (RC} as used in this manual may be
misleading. It is not an 8 pole RC
Filter. A certain amount
of feedback still remains in 3 of the two-pole sections.
Comments