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BartC BartC is offline
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Default How long can a TV extension cable be?

"tony sayer" wrote in message
...
In article , BartC scribeth


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

(In fact, I'm just done a test on a digital TV, disconnecting the RF lead
at
a joint: if the outer screen is in contact, I start to get a picture when
the inner core is 2 or 3 mm away from the centre pin! So the signal can
jump
an air gap of a tenth of an inch, and from one point to another, while an
unsoldered wire will have a 1 or 2cm length in a hollow tube so a greater
capacitive effect)


Sorry but thats not very good practice or science come to that. If in
the RF I work in we had unsoldered joints there would be fires and
smoke;!..


The signal from a TV aerial is at microscopic power levels. And I do tend to
bend the inner core of the coax to make sure it makes contact inside the
hollow pin of the plug.

But if it doesn't, doesn't it just form a tiny capacitor? (And I wouldn't be
surprised if the first thing the signal encountered inside the TV was an
actual 10pf or 100pf series capacitor.)

--
Bartc