PCL 85 - PCF 80 - PCC84 - PCC189 - PCF
86 - PL 36 - PY
82. These are all old TV valve types. For those of us who
started repairing (UK) TVs back in the early to mid 1960s, the
letters and numbers will bring back fond memories ...and does
anyone remember the ion trap? Ah! those were the days.
TV models. Here are some VHF 405 line
ones that were 'cutting edge' technology at the time: Murphy - R.G.D - McMichael - Dynatron - Raymond
F.90 (Arrgh!) - Baird 480 series - Sobell
model series 192,3,4,5,6 and 7. (the Sobell 192 was the
first TV I ever worked on).
VHF Aerials. Some areas were not
particularly well covered by VHF television signals. Even so,
Aerial erectors were expected to get the customer a viewable
'snow-free' picture. Aerial erecting teams consisted of two
members. The 'Rigger' and the 'Riggers Mate' They would often struggle for hours
trying to find a good spot for the aerial where a decent signal
could be obtained. A few feet in either direction could make all
the difference. It was nice to live in a 'leafy' area but large
trees can really affect TV signals.
The procedure for optimising signal was that the rigger up on
the roof would swing the aerial about in the general direction of
the transmitter. The riggers mate's role was to watch the TV
picture and shout up at the rigger when the best results were
obtained. They used to wear the carpet out running between the TV
and garden in order to look at the picture then shout up at the
rigger (Oh! for a bit of today's communications). The rigger had
normally moved it a bit by the time the shout came so it was a 'hit
and miss' type of operation that could take half a day in areas of
weak signal. The best spot for the aerial usually turned out to be
on the ridge of the roof halfway between the chimney stack and the
gable end, where there was no possibility of a fixing ("It's no good, you'll just have to stand there and hold it
It was pointless getting technical and using a compass to locate
the direction of the transmitter. Various factors came into play to
negate that approach. Nearby obstacles caused 'ghosts' almost as
strong as the signal coming from the direction of the transmitter.
In a location near us is a huge gasometer (still there but no
longer used). The height went up and down depending on how much gas
was pumped into it. This was is the largest gasometer in the South
of England. It's a preserved structure would you believe! Just what
is supposed to be worth preserving about a larger than average,
quite rusty, gasometer for heavens sake! Anyway, there were good
days and bad days for television reception in that area. It
depended on how high the gas dome was at the time. In desperation,
the riggers even tried pointing the aerial pointing at the dome.
That never really worked though.
An astounding discovery! This is
nothing to do with the above but an enterprising rigger found that,
in many cases, the main type of aerial that our company used worked
better when pointing in totally the opposite direction to where the
signal was coming from. From then on you could drive around and see
a significant number of aerials all pointing the wrong way!
A Double Delta works wonders. For
really weak signal areas there were 'double delta' arrays. These
were large aerials that kept the riggers busy every time the
weather got windy. With the coming of UHF signals things got
better. Although there are weak signal problems now it's nothing
like the trouble experienced with the old VHF system.
The transition from VHF to UHF. When
UHF transmissions started in UK it was necessary for TVs to be able
to handle both the new 625 line UHF standard as well as the 405
line VHF one. To this end, conversion kits were available for some
405 line models. Later, TVs would be built for the job. An early
TV, designed from the bottom up for both systems, was the
Sobell/G.E.C 1018 and 2018 (same chassis,
different cabinets). These were termed 'Dual standard' TVs. A
multi-contact slide switch (known as a 'system switch') switched
between the UHF 625 line and the VHF 405 line systems. It was a
great source of trouble and no doubt accounted for a large boost in
the sales of switch cleaner. Sometimes the contacts actually burned
out due to arcing as they switched between one system and the
other. One by one the other TV stations started transmitting 625
line UHF but it was a number of years before 405 line VHF
transmissions were switched off.
Colour TV brought out dual standard
television models like the Baird 700 and 701 -
Sobell / G.E.C 705 designed to receive BBC2 625 line UHF
colour transmissions. The standard adopted was the German PAL system.
In England we have a brand of dog food called PAL. The
advertisements for the doggie delight informed us that PAL stood
for: Prolongs Active Life. A joke was made
about it so many times that we all got sick of it. However, many
engineers who hadn't been on training courses but just 'picked the
job up', didn't know what the letters stood for. Well, we all knew
that the letters actually meant Puff A
Little because of the weight of the TVs. What the letters
really stand for Phase Alternating Line.
The PAL colour signal incorporates a feature called swinging burst, which naturally got called 'swinging
bust' with much childish giggling.
BBC2 was the only channel in glorious colour. It got watched
just for the sheer novelty of it being in colour, even if the
program was awful. BBC1 and ITV continued to be black and white on
the old 405 line VHF system for some time after colour
Of course it'll work! Initially our
company would only install colour TVs where 600 microvolts of
signal could be obtained. It was felt that signals below this level
this would not produce a reasonable colour picture. Well, business
is business and, in the end, that criteria came down. In the end it
was a case of anyone who could afford the price of a colour TV had
one. It was up to the engineers to eke the last drop of performance
from it by using the many internal adjustments that colour TVs had
in those days. To our great exasperation, some of the more
'exacting' customers had almost daily visits from engineers. Most
of our area didn't meet the original 600 microvolt requirement.
Eventually a signal repeater was erected about 20 miles away. Many
customers got a new aerial (the old one was a different signal
group so couldn't be used) and pointed it towards the new signal
source. It worked for many but there were still places where signal
coverage was less than ideal.
Customer relations. It can be gathered
from reading the above that the most important factor in creating
happy viewing was presenting the TV tuner with a good signal.
Customers who were fortunate enough to live in houses where signal
was good only called us out for genuine faults. Those suffering
from 'snowy' weak signal pictures repeatedly called on us to do
something about it. Unfortunately there was mostly little that
could be done. It was more a case of, often pointless, tweaking of
the internal adjustments and controls and much talking that was
Engineers needed a good, almost bedside, manner (in the doctor
sense) to keep customers happy. Many engineers who were technically
very good could upset customers because of poor diplomatic skills.
Those who were able to talk about gardens, pets or D.I.Y. projects
as well as technical problems on the TV were often asked for by
name. Even though a house visit might bring no improvement to
picture quality, it was keeping the customer for the Company that
was of paramount importance. Being able to turn a slightly hostile
situation into a friendly one was as equally important as being
able to mend TV's. In a purely business sense it was more so.
..More to come...