ITV Breakfast

Yes, the Golden Shot first originated from Elstree. I did once ask an ex-IBA bookings lady who was very knowledgable about such matters what the circuit idents were from/into Elstree but she could not remember, I was once told by someone who worked there that the circuits were taken out in the 1970’s (hence my earlier comment), but I suppose it could have been radio links as required.

Technically it just required the sync pulses. The video data can be that for a completely black screen as the teletext data is in the VBI.

It's possible Elstree was linked to Harrow Weald, either by cable or SHF ?

http://www.dgsys.co.uk/btmicrowave/sites/176.php

It was a matter of cost, it obviously required the transmitters to be switched on too, which nationally was a huge electricity cost, and also ate into the Klystron hours (hideously expensive items to maintain and replace)

Between 1978 and 82 BBC 2's transmitter network used to be shut down between the end of Play School late morning, and early evening to save money

With that in mind, what was the justification for a few ITV companies to be showing Jobfinder in around 1987 for between three and six hours overnight? This must also have cost quite a bit in the affected areas, and this amounted to little more than showing a testcard for hours?

I was inclined to think that switching on and off such high power machinery over the course of a day would potentially damage it in the longer run due to repeated expansion and contraction of parts with temperature.

There was indeed a trade off. Someone from the IBA once told me that after 24 hour running came in for the four channels, there was a reduction in mast feeder faults. If you have a 500ft long feeder one moment carrying 4 x 10kW, then an hour later carrying nothing, there's a measurable mechanical contraction of it, that fatigues the internal joints and components (Transmitter feeders are solid metal affairs, about drainpipe diameter)

I suspect 6 hours was probably the break even point. Pre TV-am ITV close-down was typically 00:30, and nothing until 08:30hrs.
By 1987 24 hour running was on the radar anyway.

Didn't the BBC worry in the 50s, that all night election coverage might lead to the transmitters catching fire ! ?

Yep - "producer Grace Wyndham Goldie managed to persuade the BBC to let her put on a programme on election nights to report the results (over the objections of engineers who thought it was dangerous to the transmitters to keep them on overnight)."
http://www.election.demon.co.uk/pt1.html

Probably been seen already but here’s the start of the ITN/TVAM joint 1983 election coverage

https://m.youtube.com/watch?v=w4Xjx39NPkA

Interesting because for that morning only, the ITV companies retained having the network signal through their studios (in order to provide regional news opts as mentioned.)

I was living in TSW Land at the time. There was a part networked movie that was shown between 4am and 6am. The smaller ITV companies opted not to show it. TSW had two hours worth of their station continuity clock, and silence (or maybe tone)

On an unrelated note, amazed to see web hosting on the Demon domain still exists - I thought Vodafone had axed Demon?