Quadrifilar helix antenna for low orbit earth satellites, very good reception at 136-137MHz, super gain in low horizon 5,0 db 19° and at 90° 4,8 db as well, without dark nulls of reception, The setup is 0,5 turns with 4 RHC elements and ratio 0,35 diameter / high, heavy type construction made of 6062 aluminum for high resistance, the mast has diameter 32mm and the elements diameter 10mm, Can take masts up to 60 mm, connects to a 50 ohms with 1m coaxial H-155 by a N-type female Connector. The SWR is less than 1,3:1