Tony, thanks for your excellent explanation of TV technology! I cannot
remember having seen anything that compact, yet concise, before.
And, yes, SCART is horrible, but unfortunately often no way around it.
For the antenna cable...
> Over here, we use a 'Belling Lee Coaxial Plug' (often called a 'TV coax
> plug') for the RF connection (the rest of the world often call this a PAL
> connector for some unknown reason). F connectors are used for the 1GHz (or
> so) first IF of satellite TV receivers. 300 ohm balanced cable is
> unheard-of for TV aerials over here.
Is the "Belling Lee Coaxial Plug" what I know as an IEC-type 75 Ohm
connector? - It has a larger diameter than F connectors, and is neither
threaded nor otherwise locked (not like BNC, for instance). At least,
this "IEC type" is the name by which catalogs list RF connectors for
radio and terrestrial TV use in Germany (the difference between radio
and TV is just male/female being reversed). For satellite TV, we also
use F connectors (after the LNB has mixed the RF down from somewhere
aroung 10GHz to somewhere around 1..2.15GHz).
Balanced (unshielded) cable for TV antennas had been in use in Germany,
too, but it had 240 Ohms impedance, and it was replaced by 75 Ohm Coax
about at the time when valves were replaced by transistors. I still have
one or two baluns, and some audio gear that requires them. It was kept
around for audio somewhat longer than for TV, probably because it is
easy to connect a dipol antenna for FM reception this way. In houses
built during a certain period of time, you frequently find left-over 240
Ohm antenna cable in the low-voltage wiring for the door bell...
--
Andreas Freiherr
Vishay Semiconductor GmbH, Heilbronn, Germany
http://www.vishay.com
Received on Tue Jun 18 2002 - 06:30:37 BST