B&K 1076, Инструкция по эксплуатации

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operation may be necessary to accomplish this. (For example
Channel 3 & 4). Allow the monitor receiver to sync to the On-the­
Air signal and observe the Analyst signal :floating by horizontally.
Adjust the HORIZONTAL control so that the Test Pattern picture
stands straight up and barely floats by the TV station picture. This
puts the instrument exactly at station horizontal frequency.
9. Set the AUDIO SWITCH to the "Tone" position. This will turn
on the sound channel with a 400 cycle audio tone as the modula­
tion. You will now be receiving a complete TV test pattern and
an audio tone signal which is being generated by the Television
Analyst and going completely through the monitor receiver.
In order to get the "feel" of the front panel controls, we will
now adjust some of these controls to see the effect on the picture
in the monitor.
Notice that adjusting the Video Control will change the contrast or black
to white ratio of the received test pattern. The correct setting for this control
is such that the picture shows the full range of greys. If this control is set
too high, the picture will tend to overload and distort. Slides or photographs
which have greater or less density than the test pattern slide will require a
different setting of this Video Control for proper contrast.
Th R.F. Attenuator Control will allow maximum output signal when turned
to the maximum clockwise position. As the R.F. Attenuator is turned down the
output signal is gradually decreased until it falls to zero output. Zero output
does not occur at the point marked zero on the R.F.-I.F. Attenuator but will
occur at some point above it. Just before the output falls to zero an unstable
condition is reached due to the extremely low level of the signal being trans­
mitted. This unstable condition occurs at a level too low to be useful and can
be ignored.
10. Turn the Audio Switch to external Audio position and inject audio
signal from an external source into the External Audio Input Jack
on the rear of the chassis. This signal volume can be controlled
with the Audio Gain Control, also on the rear of the Television
Analyst. Now, instead of a tone, the audio signal being received
at the monitor TV receiver will be the audio signal being injected
into the audio input jack of the Analyst. The built-in audio
amplifier will accept signals from .01 to 5 volts, either low or high
impedance. The volume control provides a means for adjusting
levels to prevent over modulating the R.F. carrier. The 4.5 me
audio channel oscillator is accurately controlled even under varying
line voltage conditions to stay within allowable frequency drift
limits. The sound channel is frequency modulated with approxi­
mately 25 KC deviation at a frequency 4.5 me above the video carrier.
After the user has become familiar with the operation of the main controls
on the Television Analyst, he can proceed to learn to use the other signals
available from the unit. (WHENEVER TESTING A TRANSFORMERLESS
TV SET, USE AN ISOLATING 1: 1 TRANSFORMER FOR SAFETY.)
11. Connect the R.F.-I.F. output cable to the grid of the first I.F. am­
plifier of the monitor TV receiver (making sure ground end goes
to ground).
12. Select the I.F. position of the R.F.-I.F. Selector Switch.
13. Tune the I.F. Tuning Control to the correct I.F. frequency for the
particular model receiver you are using as a monitor. The I.F.
frequencies of the receivers being manufactured today and those
produced within the last few years are mainly in the 45 me region.
There are, however, many sets in operation which still use the 25
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