Magneto ringing is made with the help of a built-in electronic pulse generator. A call is made by pushing the button on the case of ТА-57-U. The opportunity of light indication of subscriber’s line condition (line integrity, break, short circuit) is provided as well as acoustic signaling of power battery condition (discharge).
The field telephone has a built-in receiving acoustic device.Switching on/off of the micro-telephone headset circuits is provided by means of reed relay.
The telephone’s circuit is protected from lightning discharge near the lines, from accidental touch of the line to the wires of electricity networks.
ТА-57-U provides remote control of a radio set.
The telephone ТА-57-U spans attenuation 47.8 dB (5,5 Neper), that provides a reliable communication:
- through field cable line P-274М up to 44 km;
- through overhead communication lines with wire diameter 3 mm and operating rang 150-250 km.
ТА-57-U ensures reception of acoustic call signal with volume not less 80 dB from magneto with capacity not less 2W and through line attenuation 47,8 dB (5,5 Neper).
*Power supply of the telephone is “Ataka” battery 10V, capacity- 2,7 ampere/hour (or GB-10-U).
MAIN TECHNICAL SPECIFICATION
|Input resistance modulus on a 1000 Hz frequency, Ohm|
Output voltage of the Field telephone ТА-57-U at a frequency 1000Hz, V
Electrical resistance of isolation, not less, MОhm
а) mean-time-between-failures, h
б) average working life, years
в) recovery time, min.
Dimensions, mm, not more
Weight, not more, kg
Operating temperature: -40°C to +50°C, relative air humidity-not less 98% when temperature is 25°C.
*ТА-57-U is produced without battery.
|Comparative technical specification of Field telephones ТА-57 and ТА-57-U|
|№ Specification Field telephone|
|1. Radio communication in field conditions +||+|
|2. Operation in LB (local battery) system +||+|
|3. Operation in CB (central battery) system +||+|
|4. Attenuation span, Neper 5,5||5,5|
|5. Maximal length:|
|1) field cable line P-274 M; 44 km||44 km|
|2) overhead communication line with wire diameter 3 mm ; 250 km||250 km|
|6. Power supply 10 - 6,0 V||10 - 6,0 V|
|7. Power source GB-10-U-1,3 GB-10-U-2,7 "Ataka"|
|8. Power consumption in transmission mode not more 8 mA||not more 5 mA|
|9. Power consumption while sending of magneto ringing -||not more 0,5 A|
|10. Battery lifetime min 6 months||min 6 months|
|11. Loudness of acoustic ringing reception Not less 64 dB||Not less 80 dB|
|(reduces while increasing of the line length) ( does not depend on the line length)|
|12. Type of ringing Electro mechanical||Piezoelectric|
|13. Type of switch hook Mechanical||Electronic|
|14. Type of magneto ringing generator Hand electromagnetic inductor Electronic|
|15. Periodical necessity of contacts cleaning +||-|
|16. Indicating light:|
|-sending of magneto ringing; -||+|
|-break of a subscriber's line; -||+|
|17. Audible signaling about battery condition:|
|-50% discharged; -||+|
|-totally discharged. -||+|
|18. Changing of ringing signal tonality -||+|
|19. Dimensions, mm 222x165x80||206x165x80|
|20. Weight, kg 3||2|