Advice For Class 1

5 effective ways to do early in your phd

The single-channel equipment of voice-frequency telegraphy of P-314M is intended for receiving one cable communication on the telephone high-frequency or radio relay channel with preservation of telecommunication on this channel.

Set of ATT and system of transfer at connection to which terminal cable devices (TGA, the special equipment) is provided an exchange of parcels of a direct current is called as the channel of voice-frequency telegraphy.

To plus parcel in an operating mode currents of two or a current parcel in an operating mode current of one there corresponds the top working frequency (3205 Hz), and a minus or bestokovy parcel — the lower working frequency (3095 Hz).

The block of control and switching serves for an of cable chains in the modes I, II or III, measurements of tension and currents in the main chains, switchings of diets of the transferring and reception devices, for adjustment of the channel "on itself" and with the next station.

The cable devices working with current of two directions can turn on only with the divided chains of transfer and a. The devices working with current of one direction can turn on both with divided, and with undivided chains of transfer and reception.

Therefore, at a startstopny way of a correcting the divergence on a phase of the transferring and reception distributors can occur only during one turn and this divergence is eliminated after each turn with a stop of the reception distributor.

The quantity of the information parcels transferred for 1 sec. is called as the information speed (R). 1 bps is taken for a unit of measure of size R. Therefore, if one seven-element code combination from a telegraph exit, is transferred for 1 sec., In = the 7th baud, and R = 5 bps if for 1 sec. ten code combinations are transferred, for example, speeds of transfer make respectively the 70th baud and 50 bps.

ATT happens single-channel and multichannel. The single-channel equipment occupies only insignificant part of a voice-frequency range therefore at its inclusion in the TCh channel telecommunication on this channel remains though its quality because of change of a range worsens a little.

If on windings pass identical in size, but currents, opposite on a, the anchor remains at that contact at which was. If currents in the direction are also not identical in size, movement of an anchor is defined by the direction of current of bigger size.

The additional attenuation brought in the highway of transfer of the channel by the P-314M equipment at a frequency of 800 Hz makes ±0,05 Np and does not exceed 0,1 Np at frequencies of 300 and 3400 Hz and 0,4 Np at frequencies of 2400 and 2800 Hz. The attenuation brought by P-314M in the highway of reception of the telephone channel does not exceed 0,15 Np at a frequency of 800 Hz, 0,25 Np at frequencies of 300 and 3400 Hz and 0,4 Np at frequencies of 2400 and 2800 Hz.

Range of operation of the telegraph is determined by channels of voice-frequency telegraphy by the extent of these channels; range of operation of the device on constant air-lines of communication does not exceed 300 km., and on field cable lines - 50 km.