Thank you for your reply Manjunatha_hv,
I think that c.impedance make differences only about the magnitude of reflection but not that huge difference.
The values that i gave to COAXP2 are: Di: 0.9mm, Do:2.95mm, L:25m, K:2.295(dielectric), A:0.177 dB/m , F:100MHz
The values that i gave to COAXI2 are: Z:50, L:25m, K:2.295(dielectric), A:0.177 dB/m , F:100MHz
Characteristic impedance of COAXP2 is calculated as 46.965 ohm
I send a short pulse at 1MZ frequency with 2V magnitude and the magnitude of COAXP2 reflection is 0.1012 V and of COAXI2 is 0.9697 V for 25 m RG58 coaxial cable.
The thing i can't get with same "A" value how do i become different results. Which attenuation is more similar to reality