Central Electronics DQ Altro
Immagine 1 di 1 caricato da: RICH MC CLUNG WA6KNW
Se avete altre foto o manuali per la
Central Electronics DQ potete caricare i file qui .
The «Q" Multiplier is a selectivity device for use with
either the Sideband Slicer or any Receiver
having an IF
frequency range from ¿50 to 500 kca. Model AQ is intended
for use with Model A Sideband Slicer end. converts, the
Slicer to Model E. Model DQ is a Desk Model for use with any
in the above IF frequency range.
The unit consists of a high "Q" coil connected in a vacuum
tube (6AB4) circuit so that by means of feedback, the
effective "Q" of the coil is Multiplied many times. This
results in a very high "Q" and a very high impedance at
resonance. It may be used to increase the IF selectivity in
the PEAK position, or else to put a "notch" in the IF
passband in the NULL position.
Basically the unit has two separate signal paths; the "Q"
channel consisting of the 6AB4 with the triode section of
the 6U8,and the second channel consisting of the pentode
section of the 6U8.
In the OFF position of the switch, the 6AE4 is disabled and
the pentode section of the 6U8 is used as an IF Amplifier
With this stage of amplification, the-AP-1 is no longer
In the PEAK position the pentode functions as a grounded
grid IF Amplifier
for the "Q" channel. With the SELECTIVITY
control fully counterclockwise, some selectivity is added at
the frequency to which the "Q" circuit is tuned. Advancing
the SELECTIVITY control increases the selectivity until the
circuit goes Into oscillation. At the point Just before
oscillation, the bandwidth is only a few cycles. This
position is useful for CW, AM, FM and SSB, by using the
proper amount of selectivity. Advancing the selectivity
control too far on phono reception will result in loss of
intelligibility due to the restricted bandwidth. Generally
more selectivity can be_used on strong and undistorted signals.
If a strong heterodyne cannot be reduced sufficiently in the
PEAK position, it will be necessary to switch to NULL.
In the NULL position both channels are used. The desired
signal and the interfering carrier is applied between grid
and cathode of the 6U8 pentode and to the "Q" Multiplier
channel. Due to the high order of selectivity obtainable in
the "Q” channel, the interfering carrier may be separated
from the desired signal by timing the "Q" circuit. This
interfering carrier passes through the triode section of the
6U8 operating as a cathode follower and is cathode coupled
to the pentode section. At this point the carrier from the
"Q" channel is 180° out of phase, cancelling the interfering
carrier in the signal channel.
la actual practice, when it is desired to null out an
interfering carrier, proceed as follows:
CAUTION: When attempting to remove an interfering carrier on
an AM Phone
signal (with the Receiver
in Normal reception),
be sure to tune the ”Q" circuit to the interfering carrier
and not to the carrier of the desired signal. Removing
either one of the carriers will eliminate the heterodyne,
but eliminating the desired carrier will result in severe
distortion. This does not apply when the Slicer or EFO are
used to reinsert carrier.
The built "Q” Multipliers are shipped -using the 60 mmfd.
section only on C1Q4, the TUNING capacitor. With receivers
utilizing a mechanical or lattice filter, or other extremely
IF system, the stator lead should be changed over to
the 30 mmfd. section (3 plates) to obtain greater TUNING
bandspread. When older receivers are used which have an IF
passband of 20 to 25 kilocycles, both sections of C1Q4
should be wired in parallel in order to cover this range.
Servizio e manuale utente
Tipo di manuale:
Servizio e manuale utente
176.12 Kbytes (180343 Bytes)
ID del manuale:
05 luglio 1955
Documento scansionato, la lettura in parte male, non in parte leggibile.
09 luglio 2017