"Mike Andrews" wrote on Tue, 8 May 2007 11:11:15
EDT:

On Tue, 8 May 2007 03:15:51 EDT, BNB Sound wrote

I've been an amateur operator for a little over a year now and one of
my favorite parts of the hobby is soaking up stories from previous
decades. One of the things I'm curious about is professional HF work.
I've heard it mentioned in passing that when the early trans-Atlantic
cables went down they would shift to HF circuits as available to try
and pick up the slack.
So, what else is out there. I know the military has always been
heavily invested in radio gear, but what else was (and is?) there? I'd
love to hear from anyone who ever brought home a paycheck for working
the airwaves.

When I was stationed at Camp Drake, Japan, some time after Len left,
we were still using HF circuits to ship data (60 Baud TTY, 2400 Baud
"high speed data", and other stuff slower than 2400 Baud) to various
places around the world. I was there 2 years, starting in Jan '68. The
TX and RX sites were in Kashiwa and Owada, though I can't remember
which was which.

Kashiwa was the transmitter site built on an old WWII airfield with
about two square miles of mostly wire antennas (lots of rhombics),
NE of Tokyo. Owada (for Camp Owada) originally was a shared
USA-USAF receiver site with maybe twice the antenna field size
scattered over numerous small farms NNW of Tokyo. Army built
most of it and control was transferred to USAF in 1963. In 1978
nearly everything was given back to the Japanese government.
Parts of "Owada" receiving site was still active a decade later but
under control of the US Intelligence Agencies as an intercept site.
[no public info on such work :-) ]

We also used HF circuits at Osan AB, ROK, and some other places where
I was stationed. Never a hint of Morse, though; it was all TTY and
synchronous data.

True. Even during WWII the teleprinter was the majority
communications medium for the military, regardless of the stories
that have circulated on morse code use from that War. The center
for Army worldwide communications was Fort Detrick, MD, or radio
callsign WAR (Washington Army Radio). :-) There were separate
transmitter (Woodbridge, VA) and receiver (La Plata, MD) sites with
the control center at Ft. Detrick being primarily a TTY tape relay
unit feeding the Pentagon and 70-odd TTY trunk circuits to major
communications centers worldwide. Tape relay folks used the
network identifier rather than radio callsign. WAR had "RUEP" at
Fort Detrick while Far East Command HQ in Tokyo had "RUAP."
[TTY node IDs always began with "R" but I never found out why...]

TTY was much preferred for several reasons: It was fast, 60 or
100 words per minute with electromechanical terminals; it would
have a printed record at both Tx and Rx relay nodes; it could be
on punched paper tape with printing, ideal for human relaying to
other terminals; it could be encrypted-decrypted on-line or off-line,
vital during hostile times such as the Cold War. Note: The USA
rolling-key encryption system used from WWII until the capture
of the USS Pueblo was never known to have been broken by any
foreign intelligence service. TTYs never needed bathroom breaks,
were "fed" only when paper and ribbons reached their end, and
could work 24 hours a day. The USA, USN, and USAF operated
their parts of the Defense Communications System 24/7...and
there were trade-offs between all branches on the HF circuits,
each branch helping the other out of local problem situations.

Between the end of WWII and towards the beginning of the
1980s the worldwide military radio communications networks
were immense, larger than the combined resources of all USA
civilian radio communications networks. The Army's networks
in Europe, primarily Germany, are illustrated on the excellent
historical site (1945 to 1989) www.usarmygermany.com by
Walter Elkins. In the Far East of 1962 the Signal Corps had

http://sujan.hallikainen.org/Broadca...phabetSoup.pdf

By 1970 the US military had a better overall organization and
new kinds of equipment. Troposcatter (on low microwaves) was
replacing short-haul (under 400 miles) HF radio circuits. LOS
microwave links were replacing more and more land wire circuits.
AUTOVON (automatic voice) and AUTODIN (automatic digital)
circuits came into being, integrated with civilian communications
infrastructure. By 1980 the military satellites were beginning to
take over the really long-haul HF circuits, offering huge bandwidth
capability and thus very fast throughput. Add to that the buried
and underwater fiber-optic cables of civilian companies leasing
space to the government and military, available throughputs into
the GigaBit region. HF radio was relegated to a standby/back-up
role where it remains to this day. Radiation-hardened comm sats
are the medium of choice for the US military now.

The Defense Switched Network (DSN) was formed out of the old
AUTOVON and AUTODIN with the Internet protocols and became
the "government's own Internet" with the added capability of very
robust encryption and the ability to tie in directly with the existing
communications infrastructure or be used directly with comm sats.
That eliminated the old HF torn-tape message system and
subsequent delays of manual relaying of p-tape. In addition, all
DSN nodes can be alerted with "Flash" priority warnings or
messages, all at the same time, something not possible with the
older HF relay system.

You do know about the Coastie CW op's pages at
http://www.radiomarine.org/tales.html? These are gripping, and in
one case I found them hair-raising.

I, too, would love to hear from non-military, non-amateur HF users.

One could go to the more affluent private boat owners who do
deep-water sailing. They use HF SSB away from harbors. Not
much radio-related "hair raising" stuff there, except maybe
what is shown on "CSI: Miami." :-)

The first chapter of the "Collins Sideband Book" by Pappenfus,
Bruene, and Schoenike shows an AT&T SSB map with direct
and switched links to worldwide locations, circa 1960. I count
about 122 stations on that map worldwide. Considering that each
commercial SSB circuit of the time could carry two voice and
eight TTY channels simultaneously, that's fairly large. On the
other hand the service was 24/7 and rather routine, not much
emotion-raising (except to the users of such services).

HF use today, other than amateur, CB, and government, is
relegated to maritime radio on deep water routes (SSB voice
and data), air carrier long-route-over-water communications
(SSB voice), BC (AM and digital voice-music), some comms
services that haven't upgraded to sats or fiber-optics, and
RF ID stations in stores. It's a changed radio world
compared to a half century ago.

73, Len AF6AY

On May 9, 11:07 am, AF6AY wrote:
"Mike Andrews" wrote on Tue, 8 May 2007 11:11:15
EDT:





On Tue, 8 May 2007 03:15:51 EDT, BNB Sound wrote

The first chapter of the "Collins Sideband Book" by Pappenfus,
Bruene, and Schoenike shows an AT&T SSB map with direct
and switched links to worldwide locations, circa 1960. I count
about 122 stations on that map worldwide. Considering that each
commercial SSB circuit of the time could carry two voice and
eight TTY channels simultaneously, that's fairly large. On the
other hand the service was 24/7 and rather routine, not much
emotion-raising (except to the users of such services).

does much if any of this survive to your knowledge?

On May 9, 9:02 am, an old freind wrote:
On May 9, 11:07 am, AF6AY wrote:
"Mike Andrews" wrote on Tue, 8 May 2007 11:11:15
EDT:

On Tue, 8 May 2007 03:15:51 EDT, BNB Sound wrote
The first chapter of the "Collins Sideband Book" by Pappenfus,
Bruene, and Schoenike shows an AT&T SSB map with direct
and switched links to worldwide locations, circa 1960. I count
about 122 stations on that map worldwide. Considering that each
commercial SSB circuit of the time could carry two voice and
eight TTY channels simultaneously, that's fairly large. On the
other hand the service was 24/7 and rather routine, not much
emotion-raising (except to the users of such services).

does much if any of this survive to your knowledge?

Not a great deal of it is publicized so it is hard to say. Most of
the government and military HF stations have changed from
massive terminals to much smaller ones for specific agencies.
Those can be seen in websites carrying SHARES information.
The government conversion to ALE techniques has changed
the nature of stations' operations and reduced the need for
large stations with fixed wire antennas.

The commercial communications world has gone over to
(largely) fiber-optic, extremely broadband carriers for
thousands of voice circuits, hundreds of data circuits, and
dozens of video-audio circuits on one routing...plus the
communications satellite transponder relay services. Note:
at present - and for several years - all the available slots in
the geosynchronous orbit have been filled by commsats.
Note: Much of the underwater cable service has been or
will be soon replaced by "pumped" (self-amplifying) fiber-
optic cable.

Communications such as ARINC stations for relaying HF
from air carriers on long routes still exist in the same number.
So do the private-boat, commercial boat HF relay services.
The availability of HF communications for small stations in
commercial work has caused a shift from reliance on the
bigger mass-communications carriers to individual company
stations.

Yes, one can still hear "other" radio signals outside of the
ham bands. There still exist the strange hum-roar of 12 KHz
commercial SSB here and there on HF but those are far less
numerous than they were three to four decades ago. There's
lots more 'new' sounds of all the various TORs that "others"
use on HF and, once in a while, a rare CW signal. :-)

Thousands of old HF stations for non-ham use have been
closed down worldwide and equipment dismantled or just
junked. Some of the USA transcontinental microwave (FM)
long-distance relay system are still in use and up (visible
to anyone driving cross-country) but fiber-optics and very
high-speed digital time-multiplexed carrier services carry
much of the long-distance telephone signals if not relayed
via commsats. Such is longer-lived and more reliable.

It's difficult for many to reconcile the changes that have
happened in communications in just a half century but
that's how it went down. On a more consumer-oriented
basis, the broadcasting industry is generally wondering
what will become of all those old analog TV transmitters
after the transition to HDTV in the USA. There's no easy
answer for that, either.

73, Len AF6AY

On Wed, 9 May 2007 15:23:30 EDT, AF6AY wrote:

On a more consumer-oriented
basis, the broadcasting industry is generally wondering
what will become of all those old analog TV transmitters
after the transition to HDTV in the USA. There's no easy
answer for that, either.

Do not confuse digital television (DTV) with high definition TV (HDTV)
which is a subset of DTV. All TV stations will be required to use DTV
but the use of HDTV is optional.

As far as the transmitters go, in general they are being junked
because most of them are near the end of their useful lives and are
held together by duct tape and baling wire in anticipation of the
transition.

73 de K2ASP - Phil Kane
Life Member - Society of Broadcast Engineers

Phil Kane wrote on Sun, 27 May 2007
23:00:15 EDT:
On Wed, 9 May 2007 15:23:30 EDT, AF6AY wrote:

On a more consumer-oriented
basis, the broadcasting industry is generally wondering
what will become of all those old analog TV transmitters
after the transition to HDTV in the USA. There's no easy
answer for that, either.

Do not confuse digital television (DTV) with high definition TV (HDTV)
which is a subset of DTV. All TV stations will be required to use DTV
but the use of HDTV is optional.

I made an "aside" for comparison and haven't confused anything.
Firstly, DTV isn't about using HF spectrum...I am very aware of that.
The transmitters for television represent a sizeable capital
investment by broadcasters. I am aware of the complaints of the
broadcast industry (pro and con) during the entire time of the "Grand
Alliance" testing that led to the eventual DTV broadcasting format
that went into broadcasting regulations. It's been years since I
"rode gain" at a control console or "took" a particular camera or tape
unit, but I do
know something of the MPEG video transport format even though it
generally gives me considerable confusion every time I've studied
it. :-)

The MPEG video transport format can accommodate four different pixel
arrangements and DTV receivers are supposed to be built to decode all
of them automatically. That video format includes the old-style
analog format (converted from analog to digital) on up to the High-
Definition TV which is considered by most consumers as "wide screen
TV." The DTV transmitters themselves handle the entirety of the video
format sent up from the studios,including the quadraphonic sound, text
for hearing impaired, and whatever else the studio central control
sticks in there.

In the old TV transmitter arrangements of any appreciable power, they
were almost always TWO, one for video (AM sorta SSB called "vestigal
sideband"), one for audio (FM) with a Diplexer (passive filter) to
connect
both to the same wideband antenna. The DTV transmitter is a single
one since ALL of the modulation information is conveyed by it, no
"extra" one for sound, seldom any need for an external filter, let
alone
a diplexer. The internal design of the DTV transmitter HAS to be
different than either the AM video or FM aural transmitters by nature
of the modulation mode. But, that DTV transmitter can handle ANY of
the video transport formats automatically. Whether the TV station
central engineering sends old NTSC video converted to "low grade"
digital format or has gone all-out to run everything in "high
definition"
doesn't bother the DTV transmitter. The end result for conversion to
DTV was a replacement of the transmitters (old) by one new one.
Draconian for the broadcasters but visual and audible pleasure for
millions of consumers receiving the DTV.

As far as the transmitters go, in general they are being junked
because most of them are near the end of their useful lives and are
held together by duct tape and baling wire in anticipation of the
transition.

I disagree with that "junk" figurative phrasing. Here in Los Angeles,
there is one central TV (and most FM) broadcast transmitter site,
Mount Wilson. It's been a few years since I was up there but all the
stations (7 on VHF, 4 on UHF) had good, long-lasting transmitters.
At the time KTLA (ch. 5) was beginning to convert to DTV; they were
a pioneer broadcaster in L.A. and this year is their 60th anniversary
here. Both studio and transmitter sites have excellent equipment and
their DTV signal is absolutely HDTV. Their morning show content
is, in my view, JUNK, but that is CONTENT, having nothing to do with
equipment or signal quality...a personal critique.

What used to be a TV "leader" in quality of equipment, NBC (ch. 4)
under the 'general's" eye of RCA, hasn't fully converted to HDTV in
their studios. NBC evening news is HDTV but local news is still
narrow TV. NBC is owned by General Electric and "RCA" exists solely
as a brand name now. I think...haven't kept up on the mergers and
acquisitions of large corporations lately. :-)

TV is above 30 MHz, definitely not in the HF spectrum. However the
type and kind of modulation carried by any transmitter will determine
whether or not it will be "junked" for a new replacement, NOT it's
supposed "held together by tape and bailing wire." If hams could run
4 KW PEP SSB on HF (not in the USA) then the ages-old Western
Electric LD-T2 SSB transmitter would be a great surplus bargain for
them...Class A stages up to the PA which is AB_2, push-button QSY
to any one of 10 pre-tuned frequencies. Problem is, the SSB format is
12 KHz wide and has internal frequency multiplexing for four 3 KHz
audio inputs combined for the output SSB modulation. A no-no for
amateur radio use, even if well-designed after WW2 by WE. Too much
modification required to fit the "tranditional" and technical specs
even
if a superb design for its intended use. That was the general point
I
was making, not something about the video format of DTV.

73 de K2ASP - Phil Kane
Life Member - Society of Broadcast Engineers

73, Len AF6AY
Life Member - Institute of Electrical and Electronic Engineers


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