🚀 go-pugleaf

In article <MSALETNI.93Jan7084800@jade.tufts.edu> msaletni@jade.tufts.edu (Michael J. Saletnik) writes:

   In article <C0GJqK.1D4@tegra.com> vail@tegra.com (Johnathan Vail) writes:

   >Cable companies pick up the "air" channels the same way you do: off
   >the air with an antenna.  No broadcast, no cable.  There is no magic
   >wire from each broadcast station to each town's cable company.

   What about cable-only channels, such as USA?  Satellite, I guess?

A cable company head end has one dish per satellite and seperate
recievers for each transponder (channel) they recieve.  This is for
HBO, MTV, CNN and other superstations.

   But I find it hard to believe that the "air" channels are picked up
   with solely an antenna.  When I grew up in the flight path of Westover
   Air Force Base, both the cable office/transmission centre and the big
   tower (receiving), weren't far away.  When a C5-A Galaxy flew over,
   the broadcast stations on cable never wavered one bit.

They use a separate antenna for each TV station.  Usually a Log
Periodic antenna from 3' to about 6' long a short distance (like
30-40') up a tower.  They are going to get a good enough signal that
multipath signals are not significant.  A plane flying over the tower
has little or no effect on the signal at all since the signal is
concentrated on the horizon.

My experience is based on tower work I have done on towers that were
also used by cable companies.  I think the Waltham one was on Prospect
hill if I remember correctly.

To identify one of these you should see a tower bristling with "small"
antennas that look kind of like a double sided comb not more then half
way up the tower.  The "spines" will be paralell to the ground
(horizontal) and point in different directions with most of them
pointing near a big city like Boston.  Or if its close to Boston
several will point to Needham where the major stations transmit from.


jv


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