Alexandra Palace transmitter

[rogerdup]

This is VERY interesting. Thank you !!
Roger

[dazzlevision]

Here is the BBC channel 1 405/VHF TV transmitter coverage map from 1959.

[Boom]

Originally Posted by Peter.N.

We lived in Petts Wood about 12 miles south of London and we frequently received Band 1 transmissions from France under lift conditions but by no means continually.

During the long hot summer of 1976 lift conditions went beserk. For most of the day in London I could receive Paris 819 lines and Sweden on a Decca CVT25 set with no end of other countries coming in too. The timebase would tune to 819 but it left a two inch border each side of the screen.

[raditechman]

Practical Television May 1950 Page 69 has a chart of Alexandra Palace TX field strengths taken from a BBC survey together with a short article.. You can read it on the American Radio History site.

I lived in SW London suburbs at the time and and remember the change over from AP to CP like it was yesterday, did not make much difference on our Pye VO9 9" TV with an "H" aerial on the chimney.

John

[Viewmaster]

Ally Pally used cooled anode triode valves (CAT's) in push pull for both vision and sound TX's.
In my collection I have a CAT9 valve, the same type that was used.
(the red glow is not the filament but LEDs !!)

The bottom half is the solid copper anode which was in a circulating water jacket

[rogerdup]

Originally Posted by Viewmaster

Ally Pally used cooled anode triode valves (CAT's) in push pull for both vision and sound TX's.
In my collection I have a CAT9 valve, the same type that was used.
(the red glow is not the filament but LEDs !!)

The bottom half is the solid copper anode which was in a circulating water jacket

A beautiful piece of vintage engineering ! I love it.

[Peter.N.]

Originally Posted by Boom

During the long hot summer of 1976 lift conditions went beserk. For most of the day in London I could receive Paris 819 lines and Sweden on a Decca CVT25 set with no end of other countries coming in too. The timebase would tune to 819 but it left a two inch border each side of the screen.

That must have been about the time we had 'Viewline' down here, you couldn't get UHF so they put a receiver on top of Stonebarrow, a local hill on the coast and received signals from the Mendip transmitter, converted them down to VHF and distributed them by cable.

I had a set on the bench which resolved an excellent test card displaying the logo 'RAI' which I subsequently discovered was in Italy!

Peter

[Richard_FM]

Originally Posted by paulsherwin

It is possible that the TV was brought to France by a British family who didn't realize that it wouldn't work there. There is a surprising amount of ignorance about different TV systems among the general public even today. I often encounter Australian and even American TVs which have been mistakenly brought to Britain, and British people are often surprised that their UK Freeview boxes and DAB radios won't work in France.

This reminds my of a TV my old girlfriend's Mum brought over from Germany.

For some reason it kept switching back to PAL B/G so there was no sound, & she kept forgetting how to switch it to PAL I in the on screen menu.

Later on she got a cheap Freeview box that needed rebooting every now & again.

Everytime we visited it was up to me to sort things out for her.