Modelling and experimental research of filter onhalf-wave resonators with quarter-wavelength links was made. The following experimental result were received: - center frequency was 3.7 GHz; - passband width was 230 MHz; - losses in the passband were not more than 4 dB; - bkocking at tuning ± 200 MHz was not less than 40 dB. It is recommended to use the filter in a microwave receiver input circuit.

Keywords: Parallel coupled resonator filters, modelling, experiment, wave S range

Modelling and experimental research of path filter of C range on opposing rods was made. In the paddband from 4 to 8 GHz losses were not more than 1.5 dB. Blocking at tuning downwards per 1 GHz was not less than 50 dB. Blocking at tuning upwards per 2 GHz was not less than 70 dB. There is a false passband 16.6 - 21.5 GHz.

Keywords: filter on opposing rods, modelling, experiment, wave centimetre range

Discusses the problems of transition from open to closed systems of connection of consumers to the heat network. On the basis of fundamental analysis of the advantages and disadvantages of the various connection schemes of buildings comparison of energy efficiency and reliability of open and closed systems of a heat supply. Basic conditions guaranteeing the possibility of the device of the closed heating systems in buildings, присоединненных to thermal networks on the open circuit. Shows the need for reconstruction of water supply systems and power supply of the building when it transferred from open to closed scheme accession to the heat network.

Keywords: heat supply, district heating, closed heat supply scheme, open circuit heat supply, individual heating unit, reliability of heat supply, energy efficiency.