Originally Posted by GaryC
That is not my understanding. I was always taught that a coax connector (as Ashbypower says) can drop the signal by 3db. Which by the way is half the power loss. But it also depends on the quality and workmanship of the connector.
They are much better out of the equation.
Well, you have to have one at the antenna and one at the radio. If you think about it the idea of halving the signal output for every connector is rather far fetched.
Amphenol make high quality connectors, they say this:
"What is Insertion Loss and how is it specified?
Insertion Loss, expressed in dB is defined as 10*log (Po/Pi) where Po= Power Out and Pi=Power In. There are 3 main causes of Insertion Loss: Reflected losses, Dielectric losses and Copper losses. Reflected losses are those losses caused by the VSWR of the connector. Dielectric losses are those losses caused by the power dissipated in the dielectric materials (Teflon, rexolite, delrin, etc.). Copper losses are those losses caused by the power dissipated due to the conducting surfaces of the connector. It is a function of the material and plating used.
In general, the insertion loss of a connector is on the order of a few hundredths to a few tenths of a dB. As with VSWR, it can be specified as a “flat line limit” or as a function of frequency. Using the same examples as the VSWR, a BNC is specified at .2 dB maximum when tested at 3 Ghz. For the SMA, the requirement is .06*SQRRT Frequency in GHz when tested at 6 Ghz. For example, at 4 Ghz, the requirement would be .06*2 or .12 dB max. Although the connectors are specified to operate over a wide frequency range, they are only specified for testing at particular frequency because the test procedure required to obtain accurate measurements of such small losses is a very precise, and time consuming process."
Note that we are operating at frequencies of only 150 MHz or so, not the levels they talk about here.