Attrezzatura informazioni:

Boonton Electronic 190-A Metro di livello
Boonton Electronic
Modello: 190-A
Categoria: Strumenti di misura
Gruppo: Metro di livello
Descrizione: Q Meter
                                    The Boonton Radio Corporation Model 190-A Q Meter operates
in the vhf range, giving direct-reading measurement of Q
values. A front-view photograph of the instrument appears in
Figure I1I-1, showing the indicating meter, connection
terminals and operating controls. Both the capacitance of
the measuring circuit anti the operating frequency are
dial-indicated, making possible the calculation of various
values of X, R, L, and C of a component under test. A
summary of the characteristics and specifications of the
Model 190-A is given in Section II.
The indicating meter is parallax-corrected to gi c precise
readings by means of a blade-type meter needle and a mirror
on the meter face. Three scales, in addition to the normal Q
scale, read XQ, aQ and LO Q. The multiplier (XQ) scale
extends the range of measurable Q values and may be used in
conjunction with any of the other scales. The aQ scale
directly indicates the difference in Q between two circuit
conditions, eliminating calculations, while the expanded LO
Q scale permits accurate reading of Q values below 100. Any
one of these three scales is read by pressing the respective
key switch, located below the indicating meter.
Also located under the meter dial are the Q Zero and XQ Zero
potentiometer controls, used for electrical zeroing of the
meter needle, and the SET XQ knob, which adjusts the output
of the internal Oscillator and permits the use of any
multiplier value shown on the XQ Scale. The FREQ. RANGE
switch and the MC knob and associated dial, at the left side
of the instrumental panel, accurately control and indicate
the frequency of the Oscillator. At the upper right corner
of the panel are the Q capacitor knob and MM1D dial. This
knob drives the variable capacitor used in the Q measuring
circuit and the dial permits direct-reading of its capacitance.
The aQ BALANCE controls, located in the lower right corner
of the instrument panel, enable the operator to zero the
needle of the indicating meter on the aQ scale when
measuring small differences in Q. The outer knob, directly
driving the dial, is the coarse balancing control, while the
inner knob gives verniet adjustment.
A power switch is provided at the extreme lower right and
the pilot lamp (lower left) lights when the instiununt
circuits arc. energized.
Four binding-posr terminals near the right front corner ol
the cabinet top permits external components to be connected
to the measuring circuit. Inductors which can be resonated
in the frequency range of thr Model 190-A are connected
directly across the COIL terminals for Q measurement. Small
capacitors and certain other components arc connected to the
CAP. terminals, and measure in conjunction with stable
inductors. The high and low potential COIL terminals
and the high and ground potential CAP. terminals are clearly
An accessory set of stable reference coils, the Type 590-A
inductors, is available for use with the BRC Model 190-A Q
Meter. These specially-constructed coiis permit checking
instrument operation and are employed in the Q measurement
of components other than inductors.
The Model 190-A Q Meter may be used only on a 60-ecle a-c
power source. Lor 50 cps operation, the Model 190-AP Q
Meter, available on special order, must he used. This model
may be operated on either 50-cycle or 60-cycle power lines,
but does not provide internal regulation of line voltage. It
is recommended that the user employ external regulating
facilities to avoid the inconvenience of possible zero
shifts and variations in the Oscillator output caused by
line irregularities. Without regulation, the accuracy of the
instrument is only slight I)' impaired.

Questi manuali sono disponibili per l'attrezzatura di cui sopra:

Tipo manuale: Servizio e manuale utente Boonton-8481-Manual-Page-1-Picture
Pagine: 30
Dimensioni: 981.96 Kbytes (1005523 Bytes)
Lingua: Inglese
Qualità: Documento scansionato, la lettura in parte male, non in parte leggibile.
Data di caricamento:
MD5: c1d9fb775542e896ff87e4cac1c0f9f3
Download: 134 dal 22 gennaio 2017

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