30-06-2019, 04:17 PM
(This post was last modified: 30-06-2019, 04:18 PM by Mike Watterson.)
Till some months before Divis outside Belfast had 625 Tests, we only had my grandparents' cast off TVs. Maybe 3 models.
I used to check the Dual Standard Rental set each day. It had a vertical linear tuning scale for UHF 625 and the rotary channels for VHF 405. The test transmissions where FAR better quality than anything we'd ever seen on our 405 sets.
Later during 1971 to 1973 I restored/repaired quite a few 405 only and dual standard mono sets. We kept one for the kitchen and one for my bedroom. I remove the sliding part of the switch on most of the dual standard models and soldered at 625.
I remember having to replace the UHF tuner valves on my grandparents' set twice. They stopped upgrading after 1969 / 1970 /1971 (not sure) and never got colour. Our first colour set was rented.
Not one of the 405 sets I restored was as good as the 625, and all the dual standard models were better on 625. Then Autumn 1973 I went to college and only after restored one mono 625 set for myself. I did sometimes work at service & repair of VTR, VCR and professional TV/Monitors after I left the BBC.
I think some people are perhaps nostalgic about 405, or had very poor 625? Though Divis would have got BBC2 a lot later than London. The 625 sets had improved.
I do remember AC coupling (Black level all over the place) on 405 sets and some had poor AGC, though not a problem on our exposed hillside with a good view of Divis and Black Mountain (UTV) in the early 1970s.
The most memorable 405 only models features (I wish I'd kept some, but impossible):
* One with photosensor to control brightness.
* A couple had VHF-FM and three biscuits for three FM radio. It took me a while to understand why you couldn't make any of them do this. I was only a teenager learning, no local technical library, no internet and little money for magazines. I knew no-one else into electronics.
* One had a cabled remote with a solenoid to advance (only) the turret and volume.
I didn't know then about leaky capacitors. Later I discovered a library in Belfast that sold photocopies of R&TVS models
About 40 years too late I have 40 of those books.
Also 525 interlace is especially bad for film, due to 3:2 pulldown. The 640 x 480 is of course NTSC derived and the USA centric 1920 x 1080 is likely derived from 1125 line analogue Hybrid HD as used by Japan. Certainly my Dell 1600 x 1200 CRT can display 1920 x 1080 @ 50 Hz progressive with 1125 line like settings in the graphics card. Reduce vertical scan for 16:9
Should there never have been Analogue WS, or SD WS, that should have waited for HD. Also for most living rooms faster frame rate rather than 4K. The WS CRTS were madness.
Should UK have waited two years and launched 625 rather than relaunching a 405 service only for rich people in the South East?
Should HD have been 2208 x 1200 (both integer multiples of 16, or 1536 x1152 anamorphic) lines. Most transmission isn't 1920 x 1080 to save money but 1440 x 1080?
Should HD frame rate have been a choice of 48 & 96 world wide? The late 1950s early 1960s saw the ending of the need to match mains (which is STILL 50 AND 60 in Japan!). Film has been 24 and for years even mechanically doubled to 48 at projection. Much Cinema is shot digitally at about 4K and 48 fps.
I've seen some HD screens upscale 640 x480, 800x600 and 1024x768 fine. The so called HD Ready are rubbish for anything.
VHS usually looks terrible on an HD screen. I've wondered why there are only "Zoom modes" and no "1:1 pixel" modes. Still, I was given a 4K TV and though larger than our HD 42" Toshiba, it does the VHS much better. It also reduces the horizontal combs on stupid INTERLACED stored NTSC region DVDs. Most US region DVDs store the film frames at 24 fps progressive and the player does the pull-down. Our old DVD player has a progressive component output so if the screen does progressive, then there is no comb artefacts. Traditionally "PAL" regions of DVDs simply speeded up playback 24 -> 25. Some discs later had pre-pitch fixed 5/6ths soundtracks.
So though I'd like to have some 405 sets in my collection, I don't miss the format.
I used to check the Dual Standard Rental set each day. It had a vertical linear tuning scale for UHF 625 and the rotary channels for VHF 405. The test transmissions where FAR better quality than anything we'd ever seen on our 405 sets.
Later during 1971 to 1973 I restored/repaired quite a few 405 only and dual standard mono sets. We kept one for the kitchen and one for my bedroom. I remove the sliding part of the switch on most of the dual standard models and soldered at 625.
I remember having to replace the UHF tuner valves on my grandparents' set twice. They stopped upgrading after 1969 / 1970 /1971 (not sure) and never got colour. Our first colour set was rented.
Not one of the 405 sets I restored was as good as the 625, and all the dual standard models were better on 625. Then Autumn 1973 I went to college and only after restored one mono 625 set for myself. I did sometimes work at service & repair of VTR, VCR and professional TV/Monitors after I left the BBC.
I think some people are perhaps nostalgic about 405, or had very poor 625? Though Divis would have got BBC2 a lot later than London. The 625 sets had improved.
I do remember AC coupling (Black level all over the place) on 405 sets and some had poor AGC, though not a problem on our exposed hillside with a good view of Divis and Black Mountain (UTV) in the early 1970s.
The most memorable 405 only models features (I wish I'd kept some, but impossible):
* One with photosensor to control brightness.
* A couple had VHF-FM and three biscuits for three FM radio. It took me a while to understand why you couldn't make any of them do this. I was only a teenager learning, no local technical library, no internet and little money for magazines. I knew no-one else into electronics.
* One had a cabled remote with a solenoid to advance (only) the turret and volume.
I didn't know then about leaky capacitors. Later I discovered a library in Belfast that sold photocopies of R&TVS models
About 40 years too late I have 40 of those books.Also 525 interlace is especially bad for film, due to 3:2 pulldown. The 640 x 480 is of course NTSC derived and the USA centric 1920 x 1080 is likely derived from 1125 line analogue Hybrid HD as used by Japan. Certainly my Dell 1600 x 1200 CRT can display 1920 x 1080 @ 50 Hz progressive with 1125 line like settings in the graphics card. Reduce vertical scan for 16:9
Should there never have been Analogue WS, or SD WS, that should have waited for HD. Also for most living rooms faster frame rate rather than 4K. The WS CRTS were madness.
Should UK have waited two years and launched 625 rather than relaunching a 405 service only for rich people in the South East?
Should HD have been 2208 x 1200 (both integer multiples of 16, or 1536 x1152 anamorphic) lines. Most transmission isn't 1920 x 1080 to save money but 1440 x 1080?
Should HD frame rate have been a choice of 48 & 96 world wide? The late 1950s early 1960s saw the ending of the need to match mains (which is STILL 50 AND 60 in Japan!). Film has been 24 and for years even mechanically doubled to 48 at projection. Much Cinema is shot digitally at about 4K and 48 fps.
I've seen some HD screens upscale 640 x480, 800x600 and 1024x768 fine. The so called HD Ready are rubbish for anything.
VHS usually looks terrible on an HD screen. I've wondered why there are only "Zoom modes" and no "1:1 pixel" modes. Still, I was given a 4K TV and though larger than our HD 42" Toshiba, it does the VHS much better. It also reduces the horizontal combs on stupid INTERLACED stored NTSC region DVDs. Most US region DVDs store the film frames at 24 fps progressive and the player does the pull-down. Our old DVD player has a progressive component output so if the screen does progressive, then there is no comb artefacts. Traditionally "PAL" regions of DVDs simply speeded up playback 24 -> 25. Some discs later had pre-pitch fixed 5/6ths soundtracks.
So though I'd like to have some 405 sets in my collection, I don't miss the format.
