On May 7, 9:02�pm, Phil Kane wrote:
On Wed, 7 May 2008 00:06:21 EDT, AF6AY wrote:
The migration of mass-volume messaging from HF to
microwaves via commsat and, later, high-speed optical fiber cable,
were done to avoid the ionospheric disturbances common to HF.

Actually, Len, the first "migration" was to the pre-fiber undersea
cables.

The first of which (TAT-1) became operational in 1956.

Both the coaxial (copper) and fiber cables under the oceans require
repeaters if their length exceeds 100 km or so. Some of the early
undersea coaxial cables with their vacuum-tube repeaters are still
functional, but their capacity is trivial compared to the fibers.

�I was involved in moving Israel's circuits off HF onto the
Haifa-Marseilles cable (and thence onto the TAT-5 cable) in 1967,
several years before the parallel Intelsat satellite service was
turned on. �We had several ISB circuits to NY - double hop, mind
you -
and the rest of our circuits were HF to London, Paris, Athens,
Moscow,
and several other European cities and thence by landline and
TAT-5 to the rest of the world.

Great story, Phil! Does any of that remain as a backup? My guess would
be that it is long gone.

From a capacity standpoint, satellites are the backup now in most
places, because the fiber bandwidth is so much greater.

It wasn't just ionospheric disturbance that pushed the change to
satellites and cable, either. There's only so much useful HF spectrum,
and the newer technologies offer many orders of magnitude greater
bandwidth.

�Of course, that all changed when Intelsat and
the fiber cables came into service.

And it continues to change. In this area, direct fiber-to-the-customer
is becoming the standard; many homes here have no copper
communications and little if any radio reception at all. Everything
comes through the fiber - telephone (multiple lines if you want),
highspeed internet, and TV. The fiber is RFI-and EMI-immune, too. The
biggest headache they present for us hams is that sometimes the
switching power supply for the customer equipment is electrically
noisy.

IMHO the real threat to Amateur Radio isn't the possible reallocation
of the HF amateur bands to other services (although that's always a
possibility, and VHF/UHF are not nearly so secure).

The major threat today, I think, is that the bands we have - MF, HF,
VHF and UHF - are slowly being made less-usable or even unusable by a
combination of factors:

1) Lack of enforcement against intruders, such as unlicensed use of 10
meters by truckers and others, spreading out from 11 meters. This has
been a problem since at least the 1970s.

2) Reduction in the number of housing units where a ham can have a
reasonable antenna system. Boilerplate anti-antenna CC&Rs have been
pretty standard since the 1970s in many areas, and once in place they
are often impossible to remove.

3) Consumer electronics that are not adequately RFI proofed.

4) Consumer electronics and other devices that make excessive RF noise
in the ham bands. As the number of such devices increases, the noise
floor in many locations rises to unusable levels.

5) A regulatory environment where the above problems are simply not
given any priority. (You know more about that than I, Phil!)

73 de Jim, N2EY

(who had a small part in the installation of some overland fibers back
in the '80s and '90s)