Anyone can do it wrong (come up with 2dB loss), but we would have a
great more deal traffic here if doing it wrong was that common.

I have measured attenuation of near everything from DC to 12GHz at the
standards bench and RG58 with BNCs for a short run (2 to 3 meters)
never presented any problems being wildly imagined here. At the
worst, the connectors (note plural) "might" show 0.2dB mismatch loss -
trivial.

On the other hand, if Jeff is so sure of this 2dB figure, it should
reveal itself in blisters to the fingers for even mild power (100W).
Since this unequivocal evidence is so obviously missing from the
records (or the testimony, as the case may be); then it is very
apparently one of those "someone heard from someone else about their
brother's friend's boss who had a customer who made this claim."

73's
Richard Clark, KB7QHC

Well let me put you right Richard, there was no high power, so burnt
fingers, this was noticed in a test set-up on a network analyser, and
subsequently the adaptors in question were tested in isolation. 'Good'
adaptors were also substituted and their loss was measured and was very low
indeed.

The problem was first noticed by a very senior consultant in the lab in
question and then checked by several other people because they could not
believe it either. The connector interfaces were checked and were Ok. No
further time was spent investigating why the problem occurred, just 2 SMA
adaptors in the bin and the rest of the adaptors in the lab checked.

So please don't denigrate other people's comment without asking about the
facts.

My comments were not about properly made connectors, that will have very low
loss, but were a caution that at high UHF and above care has to be taken and
it is very easy to introduce loss. This is particularly the case when
launching from connectors onto pc boards with microstrip or joining on to
coax cable.

Having been involved professionally for over 10 years in the design of
microwave equipment I can assure you that there is an endless list of the
ways that loss can creep into a system at high frequencies.

73
Jeff