On Sat, 09 Apr 2011 23:48:30 +0100, BartC wrote:

I never solder those things, and I expect the tiniest amount of
capacitance will do the job.

Not true. Apart from the attenuation caused, you're completely ignoring
the importance of matching the characteristic impedance of the cable to
its load. Adding a 'tiny capacitance' in series will wreck this matching,
resulting in reflections. These may be visible as ghosting/ringing (on an
analogue signal) or cause deep notches in the frequency response
(affecting both analogue and digital reception).

Actually, I often only have to hold the plug near the RF
socket on a TV, and I start to get a picture, on an analogue set at
least.

That may well be true, but it doesn't alter the importance of correct
matching.

Richard.
http://www.rtrussell.co.uk/