IVIE IE-10A User manual

Our new address
lvie Technologies, Inc.
1605 NW State St.
Lclli UT 84043
Ph: 801 - 766 - 7600
Fax: 80 1 - 766 - 8282
Audio Spectrum Analyzer
Owners and Operators Manual
January 1977
Printed in U.S.A.

TABLE OF CONTENTS
Warranty .................................................. Page 1
Introduction ..............................................
page 2
Operation ------------------------------------------------- Page 3
Octave Filter Characteristics ----------------------- page 3
IE-1OA Front Panel and Controls ..................... Page 5
Selecting The Detector Response ..................... page 8
Battery and Line Operation ------------------- ------- Page
9
Pink Noise Testing ........................................ page' 10
Calibrating the IE-20A/IE-10A ----------- ------------ page 10
Gain and Loss Testing
............................... page 11
Room Response Testing ............................... page 15
Sound Level Testing
....................................... page 19
Introduction To Sound Level ~eiisurements -- -- -- - - - -- - page 19
Body Effects On Sound Measurements
-- -- -------- - - ---- page 23
Correcting For Background Noise
..................... page 23
Adding Sound Levels ................................. page 23
Measuring dB
- SPL With The IE-1OA .................... page 25
Making DBM Measurements ----------------------------------- page 29
Identifying the Levels
of Unknown Signals - - - - ---- - - -
J
page 31
Measuring Volta es With the IE-1OA
- - -- - --- - - - - - -- --- page 34
Impedance ~onvdrters/Attenuators .................... page 36
Using ~xternaiAttenuators
--- ---------- ------------- Page 37
Measuring Output Power .............................. page 39
Measuring Gain/Loss in Audio Systems - -- ---- - - - ---- - - page 41
Operating The Precision Preamplifier ...................... page 45
IE-1OA Specifications ..................................... page 47
Architect's and Engineers Specifications ------------------ page 49
Service -- - - - - - - - - ---- -- - - - - - --- - ---- - --- --- - - - - -- - -- - -- - - - page 50
Notes --------------------------------------- page 51

I E-1OA WARRANTY
The IE-1OA is warranted against defects in
materials and workmanship for one
(1) year
from the date of purchase. During the
warranty period Ivie Electronics will
repair, or at its option, replace components
which prove to be defective provided the
analyzer is returned shipping prepaid to
an authorized Ivie Electronics service
faci
1ity. Defects caused by modifications,
misuse or accidents are not covered
by
this warranty. No other warranties are
wctronicsis
expressed or
i mpl ied.
not liable for consequenti amages.
All
requests for repairs and information
should include the instrument serial
number to assure rapid service.

I NTRODUCT I ON
In the past, real - time analysis of the audio spectrum has been an expensive
process requiring a substantial investment in test equipment. The
benefits of such analysis have long been appreciated, but the process
has been so costly that only those with sufficiently large operating
budgets have been able to afford
it.
The IE-1OA Spectrum Analyzer is a versatile piece of test equipment that
is capable of making both relative and absolute measurements in the
audio spectrum. Frequency response, amp1
i fier gain, insertion loss,
sound pressure levels, dBm and voltage testing represent a few of the
IE-1OA measurement applications. Unlike a typical voltmeter, the IE-1OA
simultaneously displays the octave frequencies of the signals being
measured. The user can select a detector response for pink noise
averaging or a fast response for real time signal monitoring. Many
valuable uses can also be made of the built
- in precision preamplifier.
Every IE-1OA is built to last. The case is aluminum, fusion bonded with
nylon, and internal construction is 100% modular. Every IE-1OA is
thoroughly and painstakingly tested to assure complete perfo~ance.
Each unit is then heat tested in an oven for 72 hours at 125 F to assure
reliability. Any unit that doesn't measure up doesn't leave the factory.
The following pages in this manual explain the many features and uses of
the IE-1OA. We suggest that
it be read thoroughly.
With your IE-1OA you should have received the fol1owing standard accessories
pictured below:
IE-1OA Audio Spectrum Analyzer.
" Fast Charge " nickel cadmium batteries
(mounted inside the IE-1OA.)
AC adaptor/charger that provides
continuous 1ine operation.
Vinyl carrying case with be1
t loop.
Standard phono plug patch cord. (Not
pictured
)
Operator's Manual with i 1lustrations
and examples
.
Figure 1
It is recommended that your IE-1OA be charged for two to three hours
after
it is unpackaged. This
will assure a full two hours of operating
time before recharging is again necessary.
Make sure the voltage selection switch on the IE
- 165A Charger/Adaptor is
in the correct position for the line voltage being used (either 115v. or
230 v. AC at 50
- 60 Hz).

OPEEAT1 ON
OCTAVE FILTER CHARACTERISTICS
The ten octave filters in the IE-1OA Spectrum Analyzer meet the requirements
of the
ANSI S1.ll - 1966 (R 1975) Class I filter standards.
A plot comparing
the second order Chebychev filters in the IE-1OA with the
ANSI standard
curves can be seen in Figure
2.
FREQUENCY RATIO - f/f,
Figure 2
In the above plot of an octave width bandpass
fi 1ter, the frequency
scale (horizontal axis) has been normalized (f/fm) so that the same plot
can be used to represent any one of the IE-1OA octave filters. For
example, the number
1 on the horizontal axis represents the filter
center frequency fm, 2 is a frequency that is twice
fm (the second
harmonic) and 0.4 is a frequency that is four tenths that of the filter
center frequency.
.
A well designed bandpass filter should a1low passband information to be
transniitted through it without significant energy loss while a11 frequencies
outside the passband should be rejected or attenuated to some degree.
Transmission loss (vertical axis of Fig. 2) is simply a measurement of
the
" attenuation " of energy (usually expressed in dB) as it passes
through a device or circuit.
If we inject a pure 1 KHz tone into an octave filter having a center
frequency of
1 KHz, the " transmission loss " would be minimal, or close
to 0 dB. However, an out
- of - band 2 KHz tone into the 1 KHz octave
fi 1ter of the IE-1OA would have a " transmission loss " of approximately
15 dB as can be seen by studying
Fig. 2.
page 3

If all ten TE-1OA filters are aligned in parallel they will have a
frequency response similar to that shown in Fig.
3 .
FREQUENCY IN HERTZ
Figure 3
An interesting question might be:
What kind of display would we expect to see on a real
- time
analyzer if we inject a pure sine wave signal at
a frequency
equal
to one of the filter centers (ie.
1 KHz)?
Many peopiewould assume that
a 1 Mz frequency tone would cause energy
to be displayed only at the
1 KHz filter position on the analyzer, but
this is not true. Remember
that bandpass filters can attenuate out of
band energy but they cannot eliminate it completely. Fi1ters that are
close in frequency to
1
KHz also detect a small part of the incoming
energy and they will display that energy on the analyzer at an attenuated
1eve1 . Depending upon the display range selected, several fi1ters could
respond to a signal, even though the energy is at one single frequency.
A 1 KHz signal fed into the filters of Fig.
3 will be displayed at the
highest amp1itude in fi1ter number
6, which, of course, is the
1 KHz
fi1ter. Fi 1ters
3 through 9 a1so respond, in varying degrees, to the 1
KHz signal at a level where the individual filter skirts intercept the
signal. Injecting a sine wave into the center frequency of one of the
IE-1OA filters results in a display of the shape of that exact sanie
filter. This property is not unique to the IE-lOA,
but of all spectrum
analyzers whether
" real - time " or " swept tuned. "
We can view the filter
shapes of every spectrum analyzer by injecting sine waves that are
wi thin the frequency range of the analyzer.