[QCWA Everglades Chapter #69] Bell System-Western Electric - Telephone Pioneers and Amateur Radio

[Bill]

 From Bill NA2M:
-Bill W2CQ

*Bell System-Western Electric - Telephone Pioneers and Amateur Radio *
I was trolling through some of my earlier musings, when I found a 
reference to the Bell System Technical Journals (BSTJ). The Bell System 
published them from the period of 1922 to 1983. They covered Research 
and Development by Bell Laboratories. They ceased publication because of 
the dissolution of the Bell System in 1982. The BSTJ articles were quite 
technical in nature but were usually prefaced by a paragraph or two 
describing the article’s technology in layman’s terms. There is a 
relationship to amateur radio in many of the articles.

The first transatlantic radio telephone circuit from New York to London 
went into service in 1927. The cost of placing that call must have been 
horrendous. The service operated in the vicinity of 60 kHz. There was no 
room for much expansion of the service due to the lack of spectrum. 
Using such a low frequency also meant that the antennas could not be 
very directive. The lack of directivity meant that one channel pretty 
much covered up any other reapplication of that frequency. Around 1922 
water cooled tubes were developed that were rated at 100 KW, so power 
was not a problem. The spectrum above 200 Meters (>1.5 MHz), was pretty 
much left to Amateur Radio. So, in the early 1920s Amateur Radio 
operators started to use those unwanted frequencies to communicate 
thousands of miles using moderate amounts of power, much as we do today. 
So, with perhaps 100 watts and moderate sized antennas, the Amateur 
Radio experimenters made a series of tests on those higher frequencies, 
bridging the gap between North America and Europe. They did not need 100 
KW and big antenna installations.

As time marched on the commercial interests began to explore the use of 
the high frequency (HF) spectrum (3 to 30 MHz) based on the work of 
Amateur Radio operators. The Bell System was using single sideband (SSB) 
techniques in carrier line facilities (C-carrier, K-Carrier etc.), to 
derive multiple voice channels on a pair of wires as early as the 1920’s 
and 19 QCWA Journal • November 2018 • www.qcwa.org 1930’s. Around 1937, 
the Bell System started to apply SSB on HF for their long haul overseas 
networks. The use of HF allowed many more channels to be established. 
The now familiar fluctuations in HF transmissions led to a number of 
studies of HF propagation by Bell Laboratories. Google “Karl Guthe 
Jansky” to see how these studies led to radio astronomy. In the 10-year 
gap between 1927 and 1937, frequency stability techniques had improved 
so the use of SSB became a reality for HF. The use of rhombic antennas 
became a standard and along with moderate to high power allowed one 
transmitter to handle as many as three channels at once. During this 
time voice scramblers were used on these overseas circuits to ensure a 
measure of privacy. So, when World War II came along there was enough 
technology in place to handle many of the demands of war time 
communications. The improved frequency stability of some of the war 
surplus transmitter oscillators from Bell Lab’s partner Western Electric 
(Google AN/ARC5 command sets) furthered the development of SSB by 
Amateur Radio operators in the late 1940s and 1950s. Many a young 
Amateur Radio operator first got on the air using a modified ARC5 
command set on 40-meter CW. It was during this period that lower 
sideband became the standard for SSB for the 160, 80, and 40-meter 
bands. Upper sideband became the standard for frequencies above 14 MHz. 
There was a good technical expedient for these standards, but that is a 
topic for another time.

On perhaps a related story, Bell Labs and Western Electric provided 
technical and equipment support for the use of HF in the World War II 
armored vehicles. The equipment used HF for some types of Command and 
Control functions. Bell Labs – Western Electric began to get reports 
that thermocouples used in RF ammeters were burning out. As you may 
recall the base impedance of a quarter wave vertical operating against a 
good ground is around 36 Ohms. If you use less than a physical quarter 
wave, then you have to add inductance or compensate for the lower 
impedance by using an antenna tuner. The base impedance becomes less as 
the whip antenna is shortened. The equipment was designed to match a 
whip of a certain length. What happened was the local commander did not 
like the long fish pole whip antenna revealing their position as the 
armored vehicles moved across the country-side. So, he had his 
technicians cut down the length of the whip. What happened next was the 
technicians readjusted the antenna tuner to match the shorter antenna. 
The shorter the whip the lower the impedance. Therefore, the RF current 
into the whip will go up, thus burning out the RF ammeter thermocouple! 
See “History of Engineering and Science in the Bell System – National 
Service in War and Peace (1925-1975)” page 324.

Apparently, HF is still a good method of mobile communications in this 
day of satellite capabilities. I noticed its use in a recent program 
called Nature. This program featured two scientists who visited the 
marsh area of southern Iraq. The security situation called for them to 
travel in convoys. The lead and rear vehicles appeared to have HF mobile 
antennas attached to the front bumpers of their SUVs. The antennas were 
base loaded and looked like fixed screwdriver antennas. In another 
documentary, there was an armored fighting vehicle in Iraq that had two 
long whips mounted in the rear folded over the top and attached to the 
front of the vehicle. The antennas were either for low VHF frequencies 
or used for HF. This is just a guess on my part, considering for the 
distances covered (50-200 miles), HF would be a logical choice. A 
further guess would be that they operated in the 5 to 6 MHz range for 
daylight communications. Our 60-meter band provides a good insight into 
the capabilities of the 5 MHz spectrum. So, you can see that Amateur 
Radio, The Bell System, Western Electric and the Telephone Pioneers were 
all related in some way. - Submitted by: Jim Muiter, N6TP