Re Ian

“Battle of the beams” sure sounds a bit like what the soviets did to European radio transmissions!

I wasn’t sure if it was too early for 405 line TV but your spot on!
Do you know what sort of bandwidth they had for sound?
I did find a video on the last 405 line transmission in 1985 on a 1938 TV which makes me wonder why Australia didn’t get TV sooner.
The EKCO radio I have is incredibly similar to the AW-98 but it doesn’t use a eye tube.

Reading some of the TV related posts on the British vintage radio forums makes me think that it is just as well Australia stuck it out with radio only for so long. We don't have to worry about standards converters in order to watch programming on one of our vintage TVs because we always had a 625 line system. The only difficulty someone may run into is channel spacing on the original 10-channel televisions, which was altered when the spectrum was expanded to 13 channels in or around 1961.

Yes in hindsight we could have been stuck with 405 lines, AM sound for years!

As it turned out we were one of the first countries to use the then-new 625 line CCIR system.
Being "late" with colour also meant we dodged valve-based colour receivers.

Another reason for the delay on both occasions was that the govt. wasn't ready to fund the ABC to implement TV / colour.

Well what did the rest of the world use? obviously the UK had 405 lines but what about other countries?

It went both ways.

The number of picture lines needs to be chosen with the relationship to frames per second which for analogue TV is chosen to be nominally the same as the mains frequency. Hence the US has 525 lines 60 Hz.

The French went for a much higher number of lines but this system was later dropped and they went with 625 lines.

I thought the US had 480 lines?
Or is 525 accounting for overscan?

Why did the uk originally go with 405 lines?

I don't know the technical reason but I'd suggest that the smaller screens of the time had something to do with it. Smaller screens didn't require high resolutions and they actually worked better with lower resolutions.