In message , Roy Lewallen
writes
Jeff wrote:
" There's no mechanism within any common type of RF connector which causes
any significant amount of loss. Various types can cause some
impedance mismatch, but not enough to cause a noticeable reduction
of signal to the receiver.
Since the OP was asking about frequencies up to 1GHz, I would be
more cautious about losses in connectors. Poorly assembled connectors
can show significant losses at 1GHz. Also I have come across
connectors and adaptors (SMA) that show loss for no apparent reason
at a Gig or so., now whether this is due to dielectric losses or some
other factor I am not sure but mechanically they appeared to be
prefect. One particular SMA barrel had a stable and repeatable loss
of over 2dB, but was clean and gauged OK.
Some of the cheap PL259 connectors also use very poor dielectric
which show significant loss at even VHF.
Regards
Jeff

I'm surprised at these reports, but not too much except for the 2 dB
connector. It must have had some internal corrosion, or perhaps
something like a helical internal contact causing an impedance mismatch
that would look like loss in a matched measurement system. (Some el
crappo UHF barrel adapters have found to be constructed that way.) I've
seen some awfully shoddy BNC connectors at ham conventions and wouldn't
use them for anything at all critical. But the OP asked if there was a
place he could find the losses of various kinds of connectors. I don't
believe there's any place you can go to find the losses of shoddily
made or improperly assembled connectors or adapters. Decently made and
properly assembled connectors of standard types show no appreciable
loss at 1 GHz. If loss is a concern, my advice is to buy name brand
connectors, and especially avoid the cheap stuff you see at places like
flea markets.

Roy Lewallen, W7EL


Even at 1GHz, I don't believe that you would get as much as 2dB of loss
even if you joined two pieces of coax by stripping the ends with a
knife, twisting the conductors together, and wrapping them in scotch
tape.
--
Ian