PICO AD145 Скачать руководство пользователя страница 23

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ADJUSTMENTS AND CALIBRATIONS

Meters - are to broadcast specification and either a VU or a PPM may be selected. A
choice of 3 scales is available for the PPM: BBC, N10, SDR.

Line-up-tone oscillator - the preset (VR6) that adjusts its level at the output of the
mixer is mounted on the output module printed circuit board.

Low-battery indicator - the preset (VR10) associated with this facility is also mounted
on the output module printed circuit board.

The low reading is set at the factory and

corresponds to a set of batteries having discharged to 9v. On a VU meter, low volts is
at 0VU.

On a PPM meter it is indicated by a separate marking: yellow on a BBC

scale and red on an N10 and SDR scale.

Left

BATT

Right

IC1

PPM/VU

Input

ON
ON

ILL

Meter Calibration

Each meter drive card has one preset potentiometer calibration control per indicator
bar; they control the adjustment of the indicator bar reading in relation to the signal
level being measured. All other aspects of the meter specification are taken care of
within the software and fixed values within the circuit components.

Access is gained to the meter drive card by removal of the output module; the drive
card being mounted on the rear of its LCD indicator. Extender cables are required to
enable the output module to be powered and operated outside of the chassis.

Meter adjustment - Set an input module for a line input and introduce a 1kHz tone
from an audio signal generator. Adjust levels to achieve a reading of 0dBu, if setting a
PPM scale, or +4dBu if setting a VU scale, at the appropriate main output, on an AC
millivoltmeter. Adjust the associated preset potentiometer to give the correct meter
reading for the signal level set.

Battery level adjustment - The low reading is set at the factory and corresponds to a
set of batteries having discharged to 9V. If a different calibration is required this can
be set by the preset potentiometer marked BATT on the above diagram.

Содержание AD145

Страница 1: ...SAFETY INSTRUCTIONS 5 POWERING 6 TECHNICAL SPECIFICATION 8 EQUALISATION CURVES 11 BLOCK DIAGRAM 12 CONNECTOR PANEL 13 CONNECTIONS 14 INPUT MODULE 16 OUTPUT MODULE 19 ADJUSTMENTS AND CALIBRATIONS 22 A...

Страница 2: ...wed by AD148 edit mixer Based on AD146 two comprehensive left and right monitor modules have been added for editing purposes If a mic line module is included for commentary or voice over purposes its...

Страница 3: ...eries metalwork thereby reducing its size and weight Facilities remain largely unchanged internally the microphone amplifier has been replaced with the one designed for AD146 and externally the mono r...

Страница 4: ...Temperature check the meter glasses for condensation If the package has been in transit during cold weather leave the mixer for at least 12 hours to allow it to return to normal room temperature Any m...

Страница 5: ...is switched off this also improves the noise performance and crosstalk Powering 48v phantom or 12v tonader may be selected before or after the microphone is connected to the module Module fix screws H...

Страница 6: ...ly unit that is connected to the mains supply to drive the mixer it must be CONNECTED TO EARTH In certain types of malfunction or breakdown earthing provides a path of least resistance for electric cu...

Страница 7: ...is the 0v connection and a voltage in the range 12v to 15v DC should be supplied to PIN 4 The power source should be capable of delivering approximately 400mA allowing some capacity for phantom power...

Страница 8: ...7 THIS PAGE IS BLANK...

Страница 9: ...m L R TRANSFORMER BAL 600R LOAD MONO TRANSFORMER BAL 600R LOAD 18dBm DIRECT OUT UNBALANCED 600R LOAD H PHONE UNBALANCED 600R LOAD TB SEND UNBALANCED 600R LOAD OUTPUT IMPEDANCE 60R L R MONO 20R DIRECT...

Страница 10: ...Q 1 2 HPF PRE TRANSFORMER 12dB OCTAVE 3dB 150Hz 3dB 90Hz OUTPUT LIMITER THRESHOLD 8dB RATIO 7 1 ATTACK 2 SETTINGS INTERNALLY SWITCHABLE 1 4mS 2 0 8mS RELEASE 2 SETTINGS INTERNALLY SWITCHABLE 1 250mS 2...

Страница 11: ...10 TECHNICAL SPECIFICATION MECHANICAL SIZE 6 I P 8 I P 10 I P 12 I P A 320 381 442 503 B 295 356 417 478 ALL DIMENSIONS IN MILLIMETRES WEIGHT 6 I P 8 I P 10 I P 12 I P 6 7 8 9 ALL WEIGHTS IN KILOGRAMS...

Страница 12: ...URVES AD 245 HIGH AND LOW EQ 20 15 10 5 0 5 10 15 20 10 100 1000 10000 100000 FREQUENCY dB AD 245 MID EQ AND HPF 20 15 10 5 0 5 10 15 20 10 100 1000 10000 100000 FREQUENCY dB AD255 HIGH AND LOW EQ AD2...

Страница 13: ...12 BLOCK DIAGRAM...

Страница 14: ...talkback preset 4 Mic line input XLRs 5 Headphone monitor jack 6 External DC power input 7 Off On switch internal and external 8 Subsidiary connector 9 Stereo return jacks L R and calibration preset 1...

Страница 15: ...nter clockwise From that point 20dB gain is available for lower level signals Unbalanced headphone monitor output appears on an A type stereo jack 5 This output is capable of driving 25R at 0dBu STERE...

Страница 16: ...tput section The mixer leaves the factory with the DIL switch set in the MONO position A three position rocker switch BATT EXT 7 selects either internal batteries or an external DC source Power to the...

Страница 17: ...hone power 2 Line input 3 Phase change 4 High pass filter 5 EQ selector 6 Auxiliary 1 selector 7 Auxiliary 2 selector 8 Panoramic potentiometer 10 PFL indicator LED 13 Input gain control 14 High frequ...

Страница 18: ...ector switch 5 Because of the inherent inaccuracy of the centre detent mechanism it is not Audio Developments practice to fit such devices to equaliser amplitude controls HF 14 MF 15 LF 16 The auxilia...

Страница 19: ...the input to the fader The Penny Giles fader 18 is calibrated 10dB from its fully open position allowing the operator to work with 10dB of gain in reserve Faders on adjacent modules can be coupled fo...

Страница 20: ...nk 8 Limiter LEDs 9 Line up tone 6 Meter illumination 10 Output limiters 12 Direct or Return 11 1kHz or 10kHz 13 Left only 14 Right only Matrix 15 Monitor output level control 16 Mono output level con...

Страница 21: ...ar each bar goes out in turn as the battery level falls When the internal or external voltage drops below a safe operating level the first segment of the battery level indicator will flash Meters may...

Страница 22: ...no compatibility to be assessed on the left ear piece and out of phase components to be checked on the right ear piece When working entirely in the M S domain the matrix will transform the mixer outpu...

Страница 23: ...nt of the indicator bar reading in relation to the signal level being measured All other aspects of the meter specification are taken care of within the software and fixed values within the circuit co...

Страница 24: ...ixer to give a level of 0dBu at L output Then select the limiter function and adjust VR5 until the output signal starts to fall typically 0 2dB The DC voltage at PIN 8 of IC 2 should be approximately...

Страница 25: ...alified engineer CHARGING If nickel cadmium cells are fitted in an AD255 series mixer they may be recharged in situ from AD100 015 power supply whether the mixer is in use or not Maximum current is se...

Страница 26: ...25 CUSTOMER NOTES AND FACTORY MODIFICATION...

Страница 27: ...26 TECHNICAL LIBRARY...

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