Coax cable, plug and adapter losses

I gave myself a little project earlier this week, to explain in layman’s terms how much is lost through a connection and coax..

I asked one of the engineers at work and he gave me the formula

IL(db) = 10log10 * power in/power out = loss in db.

So I went to work in excel using the formula, get the spreadsheet from here cable loss

Known loss of cable or plug, loss-/+ /10 10x *power in = power out..

To say I was shocked was an understatement! RG58 generic has a loss of 4.9db that equates to 10watts in @ 100mhz = 3.23 watts out! In fact you’d have to push rf through the cable @ 30 watts to get the desired 10 watts out..

Connectors are also potentially lossy, but a good connection will be <0.01db loss.. if it’s any more you will notice connections getting hot/warm at 100-400 watts and melting at >kw.