Vintage Tweeters 6GDV-6-25 25ohm Radiotehnika S90B, S90D, S90F, S100F, S150 made in USSR

Tweeters 6GDV-5-25(25ohm)Installed in Radiotehnika S90B, S90D, S90F,S100F,S150 speaker systems. Specifications 6GDV-6-25: Frequency range: 5000 - 25000 Hz Frequency response flatness: 12 dB Sensitivity: 91 dB Harmonic Distortion at Operating Power: 2% Resistance: 25 ohm Nameplate power: 6 W Max Power :10W Main resonance frequency: 2900 - 3600 Hz External dimensions: 100x100x35 mm Weight: 1pcs-1 kg. The dome-shaped diaphragm with a suspension is made on the basis of a polyethylene terephtholate film.  The voice coil is wound with a wire of the PEVL brand with a diameter of 0.08 mm, the winding is two-layer, the total number of turns is 67, in the first layer there are 34 turns, in the second - 33, the ohmic resistance is 21.7 Ohm (±1.5 Ohm).  The frame of the reel is made of EN-70 paper 0.07 mm thick.  ZK height 4.5 mm, inner diameter 25.4 mm, outer (together with winding) 25.95 mm.