RTE One in 405 lines in 2011

watty

1970s USA. Ultrasonic. Which is why most IR uses 38KHz carrier (Ultrasonic was 36KHz to 42KHz).
From 1950s to 1970s some TVs, even in UK, had cabled Remote controls.

My grandmother had a Luxor TV in the mid 80s with an IR remote but they were going around for a while before that; I once saw promo for Oracle from the 70s with it being displayed on a TV with a wired remote.

Tax The Farmers

Re: The wisdom Or otherwise of the Beeb using 405 in 1946 they probably didn't have much choice in the matter as there was little or no knowledge of the 625 line technology in the west in 1946. It was pioneered in the USSR and towards the end of the decade was taken up in Germany and subsequently the rest of Europe (the Dutch briefly experimented with 567 lines)

During the 1960's the BBC did toy for a while with the idea of 625 lines on 5 MHz VHF channels (alongside 8MHz channels on UHF in order to avoid having to replan the UK's VHF allocations. The idea was dropped -possibly to avoid the complexity of dual colour standards (The VHF system envisaged a chromince subcarrier frequency around 3.6 MHz).

RetroEncabulator

I don't think you could really say there was "was little or no knowledge of the 625 line technology in the West in 1946."

405-line was quite literally the first fully electronic television system developed by Marconi and EMI in the UK.

Analogue monochrome television standards are all basically the same technology just in different configurations to squeeze more information into certain bandwidths.

There wasn’t a ton of difference between 625 and 405 on the small screen that were typically used in the UK in the 50s and 60s.

BBC ran colour tests with NTSC on 405 which worked fine and they tried SECAM. They eventually settled on PAL, largely because it was the preferred EBU standard. It didn’t make a ton of sense to be out on your own.

The 625 line standard just happened to be optimal - able to be squeezed into somewhere between 5 and 6 MHz

The choice of UHF for 625 PAL in the UK is completely arbitrary. VHF is generally easier and RTE and plenty of others broadcast PAL-625 on VHF for decades. Australia for example used DVB-T on VHF.

UHF is far more line of sight and less suited to rolling landscapes. The only significant advantage is it requires much smaller antennas, which is a significant thing in a country like the UK with a lot of over the air reception and roof antennas as it reduces clutter.

France adopted 819 lines for example, which was far too bandwidth intensive (14 MHz!) to combine with colour subcarriers, so was dropped when SECAM was introduced.

Also there were practical implications of having to make different types of tubes for different markets.

Here’s how it looks:

https://youtu.be/yB2HB_QhZfQ

TAFKAlawhec

Holy Thread Resurrection, Batman!

Anyway...

"The choice of UHF for 625 PAL in the UK is completely arbitrary. VHF is generally easier and RTE and plenty of others broadcast PAL-625 on VHF for decades. Australia for example used DVB-T on VHF."

The UK decision for having their 625 line analogue PAL service was that there simply wasn't the space in their VHF Bands I & III to carry such a service & maintain the two 405 line services already in place - when the 405 line nets were shut down for good in 1985 they could have done something similar to the French and replan the allocations similar to that used in the ROI, but they didn't preferring to reallocate the bands for PMR mostly (a missed opportunity IMO). In much of the rest of Europe, the VHF bands were simply the first ones used for broadcasting the first (usually public or state) channel and when space ran out for them, started using their UHF allocations. The ROI was a general exception to having two national TV networks largely carried on the VHF bands, most countries could only give space for one with a second channel having to start on UHF (with some odd exceptions e.g. the Santiago transmitter in Spain carrying TVE2 on Band I whereas it was on UHF elsewhere in Spain).

As it is, the majority of European countries that used to have 625 line analogue transmissions on VHF have DVB-T/T2 transmissions today only on UHF and have largely abandoned it - even the Italians that would fill every spare channel allocation going have largely abandoned it now if the details on digitalbitrate are accurate. Of the top of my head, only Finland, Poland and possibly Sweden maintain VHF DVB-T/T2 networks today. And while Australia still uses DVB-T on VHF Band III, it is somewhat ironic that this practice exists mostly in the major cities whereas the regional and rural areas are reliant on either UHF transmissions or the VAST satellite scheme (the reasons are down to maintaining general antenna compatibility with prior analogue broadcasts). Interestingly, New Zealand did not retain their VHF bands for DVB-T broadcasting and have reallocated them for other non-broadcasting uses IIRC.

"France adopted 819 lines for example, which was far too bandwidth intensive (14 MHz!) to combine with colour subcarriers, so was dropped when SECAM was introduced."

The French, including the famed Henri de France, did tests using SECAM on their 819 line transmission network and could have ran an 819 line SECAM colour network if they wanted to, the same way the UK could have run a similar one for 405 lines on either PAL, SECAM or NTSC - however as the French authorities had agreed in the early 1960's (around the time of the Stockholm Frequency Conference in 1961 IIRC) to adopt 625 line transmissions/recordings for better compatibility with programme exchange across the EBU & elsewhere in Europe, and thus decided that the adoption of SECAM colour would be restricted to 625 line transmissions for the public and that the TF1 network would itself become a UHF 625 line service after a simulcast period (like BBC One & the ITV stations in the UK - indeed one of the main reasons for the UK adopting 625 line broadcasts as recommended by the Pilkington committee was for similar programme exchange reasons, as well as accepting that using 405 line transmissions on UHF would waste significant bandwidth as prior agreement had already been agreed for all of Europe to adopt a common 8MHz channel bandplan for 470-960 MHz TV transmissions at Stockholm 61 as opposed to the hotch potch of band plan allocations in the VHF Bands I & III that lay across Europe).

icdg

Yeah, we don’t drag up old threads. I don’t say this for fun, as I want to remind people, it’s because posters are very quick to attack old posts which are saying things that were true at the time without taking notice of the date stamp,