SIGNAL STRENGTH
A726 PROFESSIONAL SYNTHESIZER-FM-MONITOR-TUNER
UDER
STUDER A726 the professional FM monitor tuner
Professional low-distortion receiver technology for excellent selectivity and stereo channel separation
I.C. multifunction display
The monitoring and quality control of FM radio broadcasts imposes exacting requirements because it is essential to know, how the listener ultimately recei-ves the programs that have been produ-ced with elaborate quality efforts. There is no alternative: professional quality must also be extended to the monitor tupor. ner. is is why STUDER builds an FM tuner at fully satisfies the requirements of ofessional users just like all other UDER audio systems in world-wide STUDER nufacturing quality through subas-nology and comprehensive final in Lasy, convenient to operate because of separately grouped primary and secondary front-panel cont Exceptional receiver technology and grouped primary and secondary front-panel cont Drawing on the many year's of experiment in design and construction of first-quality synthesizer tuners, a new signed for convenient push-button state of the eart FM tuner, the A726, has been developed. However, it is more than simply a technical evolution of the many part of the ront pareland can be prototiones the advantages of proven, low-section receiver technology and digital control operates via serial com-mand and data bus links, the internal wirring is greated in the control operates via serial com-mand and data bus links, the internal wirre incorporated in the contrest operational reliability. and tuning. The received signal is indicat-ed logarithmically over an extremely wide range. The 7-digit, alphanumeric LC display indicates either the tuned frequ-Despite these capabilities, push button ency, the station name, or the selector key number (1 to 20). The display also provides status informa-tion of important functions such as enter,
the set push button operating concest, for see push button operating concest, with funing indicators that are in fact pre-for each programmed frequency noton-ly the station name but all specificoperat-ing parameters can be stored. Simply of mattion concerning the signal strength
stereo mode, muting, and antenna rotor movement (option).
Station tuning: convenient and flexible One of the basic advantages of digital tuning with a frequency synthesizer is the repeatably high tuning accuracy, regard-less of the station selection method. The
Despite these capabilities, push button tuning remains convenient yet flexible: manual tuning in 50 or 12.5 kHz steps; with direct digital frequency input via key-board and automatic complementation of the 12.5 and 25 kHz steps; AUTOmatic search in either direction, or recall from
20 Stations, user-programmable frequency, name and tuning mode. Microcomputer for frequency synthesizer and control functions Balanced and floating line outputs
With the RF screens raised, the clean arrangement of the receiver electronics beco
Highly accurate frequency synthesizer
- Tuning range from 87.5000 to 108.0000 MHz, sweepable in channel pattern steps of 12.5 kHz
- Frequency synthesizer with quartz reference, accuracy ± 0.002 % (± 20 (mag
- LSI synthesizer circuit with two phase discriminators, microprocessor-controlled, programmed for optimum lock-in and high spectrum clearness of oscillator frequency in the holding
- Tuning modes Automatic wrap-around search in 50 kHz channel pattern in either direction
Frequency steps for 50 and 12.5 kHz channel pattern, step-by-step and continous search.
Digital frequency input in 12.5 kHz channel pattern with automatic complementation of low-order value.
Microcomputer system control and static data memory
- Microcomputer 8440 (NMOS: 4 k x 8 bits) with serial hardware interface.
- tions.
Signal-to-noise ratio (mono and stereo) as a function of the antenna signal. Distortion spectrum, measured voltage with 1 mV antenna voltage, 40 kHz
• Static data storage (no battery required) in external EA-ROM (100 x 14 bits) for frequencies, station names, mode, status, etc.
6-way tuned RF input section, balanced mixer and passive IF filter
- Coaxial antenna inputs (IEC); identical input for switch-selectable second antenna (option)
- Matrix scan for all push button func- RF input section with band-pass filter 87 ... 108 MHz. 2 RF preselector stages and 6-way tuning by means of 18 double tuning diodes for high overdriving immunity.
extreme bandwidth, long-time stability and extremely low distortion. The coincidence demodulator works with a coaxial delay line (68.18 nsec).
- Multiplex demodulation of exceptional quality with discrete PLL decoder (no decoder IC)
- Wide-band filter for 19 kHz pilot signal for maximum phase linearity. A narrow-band loop filter ensures excellent selectivity.
High-quality balanced mixer.
- Complete IF selection concentrated in phaselinear 8-section IF filter (Thomson-Butterworth). Passive design for maximum long-time stability.
- Integrated wide-band IF amplifier. Separate AGC amplifier for accurate signal strength indication, extremely wide measuring range (0 ... 110 dBf: logarithmic) for reliable interpolation of reception conditions
- Accurate and sensitive tuning indication with separate discriminator.
Digital coincidence demodulator and-PLL stereo decoder
Digital FM coincidence demodulator. This circuit arrangement combines the advantages of conventional demodulators (e.g. high signal-to-noise ratio) with those of digital design such as
Dimensions
- Dual push-pull switching demodulator for maximum channel separation and extremely low harmonics spectrum.
- MPX noise filter that does not affect AF frequency response.
- Highly effective suppression of noise frequencies above 53 kHz prior to stereo decoding (100 kHz low-pass filter / Cauer low-pass filter with 4 attenuation peaks / band-pass filter 23 ... 53 kHz / 114 kHz bias trap).
First-quality AF section for purest audio
- Excellent pilot signal rejection by separate 19 kHz band rejection filter.
- Sophisticated 15 kHz low-pass filter at decoder output for purest audio reproduction (without residual MPX signals; important for tape monitor recordings with noise reduction systems).
- Unbalanced AF outputs via Cinch and DIN sockets plus socket-type variable output on front panel.
- Headphones monitor output on front panel with separate volume control.
- Built-in 400 Hz calibration oscillator.
- De-emphasis 50 µs (optionally convertible to 75 µs).
- Output for indication of multipath radio interference (option, BNC).
- Output for multiplex signal (option).
Balanced and floating line outputs
The A726 is designed for professional environments and can be connected without problems. High-quality balancing amplifiers supply floating line level. Unrestricted application flexibility is ensured by additional unbalanced, fixed, and variable AF outputs.
Remote control terminals
- Input for cable-type remote control of the following functions: stations 1 to 5 memory scan (for calling up all stored stations). Power on/off (standby).
- Output for remote power application to an additional unit.
For 19" rack mounting, a mask (for blanking up to 4 height units) is supplied with the tuner. A tinted plastic cover for the secondary control panel section is available as an accessory.
All dimensions in mm
Ordering information
STUDER A726 with XLR-3-M connectors No. 60.087.26001
Neat layout of connector panel with professionaltype AF sockets for line level, balanced and floating.
Technical Data STUDER A726
| Tuning range: |
87.50 to 108.00 MHz
Frequency input via keyboard, 12.5 kHz channel pat tern; 50 or 12.5 kHz STEPS push buttons; automatic search in 50 kHz channel pattern |
| Station preselection: |
20 station selector keys, user-programmable fo
12.5 kHz channel pattern. Programmable parameters frequency, name, and tuning mode |
| Accuracy of quartz reference: | ± 0.002 % |
| LC Displays: | Frequency: 7 digits |
| Absolute sensitivity: |
0,5 µV measured at 75 ohm antenna input for a signal
to-noise ratio of 26 dB relative to 40 kHz deviation |
| Useable sensitivity: |
Mono. 2 µV
Stereo: 20 µV (measured at 75 chm antenna input for a signal-to noise ratio of 46 dB relative to 40 kHz deviation) |
| Image rejection ratio: | 110 dB, ∆f = 2 x fiF |
| IF rejection ratio: | 110 dB, fIF |
| Spurious response rejection ratio: | 110 dB, fIF/2 |
| Capture ratio: |
0.8 dB, measured at 1mV/75 ohm antenna input fo
a deviation of 40 kHz, 30 dB S/N ratio |
| Static selectivity: |
80 dB, wanted signal 100 µV on 75 ohms, interferin
signal 1 mV on 75 ohms, modulated to 40 kHz devia tion |
| AM rejection ratio: |
72 dB, relative to 75 kHz deviation, 30 % AM, 400 Hz
and 1 mV antenna voltage at 75 ohm input |
| Frequency response: |
30 Hz to 15 kHz ± 1 dB, measured with an input signa
of 1 mV/75 ohms modulated to 40 kHz deviation |
| De-emphasis: | 50 us (European version), 75 us (US version) |
| Total harmonic distortion: | and 40 kHz deviation, mono and stype b rr R M |
| Signal-to-noise ratio: | tion and an input signal of 1 mV/75 ohms |
| Stereo separation: |
100 Hz 10 kHz >40 dB
1 kHz >43 dB relative to 75 kHz deviation and an ir put signal of 1 mV/75 ohms |
|
Pilot signal and subcarrier sup-
pression: (including all harmonics) |
70 dB, 15 kHz 300 kHz linear, relative to 75 kH
deviation and an antenna input of 1 mV/75 ohms |
| Trigger THRESHOLD STATION: |
2 20 µV on 75 ohm antenna input, adjustable wit
potentiometer THRESHOLD STATION |
| Trigger THRESHOLD STEREO: |
5 350 µV on 75 ohm antenna input, adjustable wit
potentiometer THRESHOLD STEREO |
| Antenna inputs: | 75 ohms coaxial |
|
AF outputs:
Output FIXED |
(Phone-sockets) Rt <500 chms
Rt > 10 kohms |
|
Output voltage:
Output VARIABLE: |
2V at 400 Hz and 75 kHz deviation
(Jack-socket) Ri < 6 kohms RI >10 kohms (Phono.sockets) Ri < 15 kohms |
| Balanced output: |
RI>10 kohms
1.55 V/600 ohms at 40 kHz deviation (1 kHz), level adjustment with internal potentiometer from 1.55 V up to 4.4 V Ri <50 ohms, RI 600 ohms |
| Output voltage limit: | 8.8 V/600 ohms (+21 dB) |
| Output PHONES: | Ri 220 ohms, output voltage 6 V at 400 Hz and 75 kH deviation |
| Remote Power On: | 6-pole socket with DC supply, controllable internal c external (10 V) |
| Socket for remote control via cable |
10-pole socket, controllable functions: station selector
keys 1 to 5, SCAN UP/DOWN and POWER OFF |
| Power requirements: |
Europe: 100/120/140/200/220/240 V AC
± 10%, switchable Capada/USA: US V AC ± 10% |
| Power frequency: | 50 50 Hz |
| Power consumption: | 30 W |
| Weight: | 8.5 kg |
| Options: |
Antenna input switch A to B
De-emphasis 75 us |
| Ambient temperature range: |
+10 +40 degree C
(50 105 degree F) |
| Relative humidity: | Class F, DIN 40040 |
Designed and Manufactured in Switzerland
Worldwide Distribution:
STUDER INTERNATIONAL AG Professional Audio Equipment CH-8105 Regensdorf, Althardstrasse 10, Switzerland Phone 01 840 29 60, Telex 58489 stui ch
STUDER REVOX AMERICA INC. Nashville, Tennessee 37210, 1425, Elm Hill Pike Phone (615) 254-5651, Telex 065230/554453 studer nas
New York Office New York N.Y.10013, 155 Avenues of the Americas Phone (212) 255-4462
California Office Van Nuys, California 91401, 14046 Burbank Blvd. Phone (213) 780-4234
Dallas Office Dallas, Texas 75223, 910 S. Glasgow Drive Phone (214) 760-8647
STUDER REVOX CANADA LTD. Toronto 17, Ontario M4H 1E9, 14, Banigan Drive Phone (416) 423-2831, Telex 06-23310 studer tor
chael-Occ STUDER FRANCE S.A.R.L. F-75015 Paris, 12-14, rue Desnouettes Téléphone (1) 533 58 58+, Télex 204744 studer f
STUDER REVOX GMBH D-7827 Löffingen, Talstrasse 7 Phone 07654/1021, Telex 7722118 rvox d
F.W.O. BAUCH LTD. Boreham Wood, Herts. WD6 4RZ, 49 Theobald Street Phone 01-953 0091, Telex 27502 bauch g
STUDER REVOX WIEN GES.M.B.H. A-1180 Wien, Ludwiggasse 4 Phone 47 33 09/47 34 65, Telex 07/5275 studr a
STUDER ITALIANA I-20133 Milano, Viale Campania 39 Phone 0039-2-719312, Telex 335230 audiom
STUDER REVOX FAR EAST LTD. Hong Kong, 2-12 Queen's Road West 25th Floor, Arion Commercial Building Phone 5-441 310, Telex 60185 srfel hx
STUDER REVOX JAPAN LTD. 1-22-2 Yoyogi, Shibuya-ku, Tokyo 151 Phone 03-320-1101, Telex 27618 rfent j
CENTELEC EQUIPAMENTOS E SISTEMAS ELECTRONICOS LTD. 22440 Rio de Janeiro-RJ, Av. Ataulfo de Paiva 135/1710 Phone (021) 259 36 99, Telex 2130842 cosl br
Le raccordement des enceintes acoustiques s'opère par bornes autoserrantes.
/ue d'ensemble des fiches de raccordement à l'arrière de l'appareil
emballement thermique en fonctionnement à grande puissance.
Le préamplificateur, disposé en face avant, est protégé par un blindage et, afin d'éviter tout rayonnement dans les câbles de liaison entre ce dernier et les prises disposées en face arrière, les connexions sont disposées sous un blindage métallique faisant office de « chemin de câbles », ce qui contribue, grâce à l'emploi de transistors FET, à l'obtention d'un rapport signal/bruit très élevé.
Il est à noter que le réglage de gain s'effectue non pas à l'aide d'un potentiomètre mais d'un véritable atténuateur calibré, à plots, associé à un circuit imprimé entre les bornes duquel du carbone a été déposé, réalisant ainsi les diverses résistances étalonnées.
L'avantage d'un tel système est d'éviter tout parasite dû à la présence de poussière sur la piste ou au vieillissement du potentiomètre.
Robuste, très souple d'utilisation, bien conçu, le HA 1100 peut être considéré comme un appareil extrêmement intéressant, et difficile à battre sur le plan du rapport puissance/prix.
© beim Hersteller Archiv Michael-Otto
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