| With the growth of budget priced
colour TVs during the 70s and 80s, black and
white sets slowly started to become a thing
of the past. However, with a generation or two
on and 40+ year olds hankering after a lost
childhood, old black and white sets are becoming
sought after.
Sets manufactured during the 50’s were
designed to work on the VHF 405 line standard
which was adopted by the government shortly
after the 2nd world war. Up until the mid 50s,
sets were shipped, pre tuned to the station
which would be locally serving the area in which
the set was to be used. In ’57, ITV started
transmission, independent of the BBC. With two
channels available, sets now had to have multi
station tuners.
In ’64, the UHF 625 line TV standard
started, now giving the viewer a staggering
selection of 3 stations to watch. UHF started
life with new BBC2 station. You had to have
an additional aerial and not all locations were
serviced with UHF. Even in a good area, you
could not guarantee good results due to poor
sensitivity of the early UHF tuners fitted in
sets. It was not until the late ‘70s,
that 90% of the UK had access to UHF. BBC 1
and ITV soon started parallel transmissions
on UHF. Switching between VHF – 405 line
operation and UHF – 625 on your new dual
standard TV set, was a bit like taking your
life in your own hands.
The two standards were very different and required
the set to process the respective signals in
different ways. This was normally achieved by
setting a large chunky switch to either VHF
or UHF. This switch was connected to a complicated
set of cams, levers and multi way switches which
altered the way of working of the RF sections,
video, sound, frame timebase and line timebase
sections of the set. If all when well when you
operated the switch, you would get a satisfying
clunk and the picture would reappear after a
few flashes, lines and crackles from the sound.
After the set had been in use for a couple
of years and full of dust and smoke deposits
for the normal Embassy No. 5s, the switches
would stick half way between UHF and VHF, resulting
in all kind if strange happenings including
the odd puff of smoke and occasional bang. You
would now be left with calling out the man in
the brown overall who would come out with the
standard phrase “sorry love, it’s
the picture valve” and stitch you up for
£7.10s.6d.
By the early ‘70s, sets were single standard
UHF only. Colour sets were becoming popular.
Rental was the option for the family with a
modest income. Early colour sets were not too
reliable. They had many valves, lots of heat
produced. In ’85, VHF 405 line TV stopped
in order that the VHF frequencies on which the
service was transmitted, could be made available
for mobile phones. Sad day.
Although the resolution was not as high as
the UHF – 625 standard, the pictures produced
on a good set were very good. The standard did
last or some 50 years, which I think says a
lot. No longer can we hear the comforting 10
Kcs line whistle of the 405 line system and
getting three times a night to adjust the vertical
and horizontal holds is a thing of the past. |
Philips
Dual Standard 17"
