Відео

4.433...... MHz not KHz.

A very nice explanation but some points: NTSC did not propose the subcarrier based of fh of 15.735KHz. In fact the fh at the time of proposal was 15.750KHz. The fh and fv were later changed from 15.750KHz/30Hz to 15.735KHz/29.94Hz to reduce sound buzz. Regarding 25Hz subcarrier offset, having viewed PAL images without any offset (PAL system M), I would argue that it was totally unnecessary. In fact it caused enormous complications to editing videotape, where 4 frames had to pass before the subcarrier was in a suitable phase to join. If you look at some of the early pop videos with fast cuts, you often see the picture move left, and even move up or down by 2-lines, as the playback circuitry tries to match the phase. Another aspect of PAL was the burst blanking that Dr Bruch specified for around the vertical blanking period. It made no sense to a PAL receiver, though it did give Japanese set makers a "hook" to understand the phase of the following burst, thus allowing them to bypass the import restrictions governed by the patent holder Telefunken.

Please post some videos of restored exhibits, volunteers work and the museum in general. Best to all.

Great video. I love electronics and technology. I also love physics and calculus. Am I weird?

Central Florida here 🌴📐

The video is entertaining and informative, but it's a poor choice for testing the system sound. With the annoyingly obvious drops, when switching from speech to silence and vice versa.

Thank you it was very well explained.

The landscape of Cambridge South is changing over 20 years of progress, this was once all fields, Soon the final section of the East West Rail link will run past Foxton on the way to Bedford.

I and Q are _not_ the same as R-Y and B-Y. They are 33° rotations from R-Y and B-Y.

Very interesting indeed, thank you!

Restore Cherry Hinton station

For me, the biggest change to Cambridge's railway landscape is the final approach to the station from the south, which is now through a grim canyon between blocks of (I presume) student accomodation.

Simple PAL was not the first version of PAL but a way for cheap manufacturers to avoid paying royalties for the PAL patents to Tekefunken. Most noticable being the first line of Trinitrons from Sony. The simple PAL receiver has a hue button like in NTSC. But no other set or brand made simple PAL receivers ever again. And PAL “D” does not exist, it is called by the CCIR notation for B/G, I, D/K, M or N which denotes line count/frame rate, channel bandwidth, sound offset, and channel spacing.

I have a large 1920s Pye sunburst radio in fabulous nick. Gets one radio station right at the back of the box....but I think its supposed to have a massive aerial....rather than a coathanger.

Keep up the good work, lovely sounds.

At 14:25 I can heat your stomach growling 😂

People Always Last.... given BBC colour was 20 years late.

Thank you!

Really excellent - thank you for the clarity and simplicity of the explanation.

I've actually implemented PAL encoding and decoding in a shader for Media Player Classic back when I was on Windows (the program is Windows-only, despite being open-source, unfortunately, and can't be ported to anything else as it's designed entirely around Windows' APIs). The simple decoder should produce alternating light and dark versions of a colour, not alternating hues. There's a subtraction step that will produce alternating hues if left out. Implementing something equivalent to the delay-line decoder via a second shader (the framebuffer inbetween shader passes giving storage equivalent to the delay-line) required leaving out that step, but the averaging in the second shader removed the alternating hues.

SECAM = Supreme Effort to Counter American Methods

😮 Excelente

We used to refer to NTSC as 'Never Twice the Same Color' :)

Excellent video! I'm surprised about how similar PAL and NTSC were. I was stationed in the US Army and was dismayed by how much better their PAL broadcasts were than NTSC (until I learned how recently they got Color TV compared to the US). Specifically, blacks were blacker. I think reds were a deeper red. And PAL seemed to lack a lot of artifacting NTSC had, like if there's white text on a black background, the white text creates a band, or ghost image, to the right where it should be black. Colors didn't bleed as much, but this could be due to greater bandwidth. The 50hz flicker was a problem for me, though.

Get rid of this intro

Thank you for a fine explanation of this complex process. Well done! NTSC originally proposed the phase alternating process. RCA called it PLA. This was dropped due to the already massive cost of a color TV receiver in 1953 dollars. By eliminating the additional delay line, a very expensive component back then, they cut some of the final cost from the product. I observed a PAL receiver at the NAB convention, in the early 1990s, that was suffering severe phase distortion and looking closely at the screen I observed that it suffered the same color shift issues as NTSC. However, with the phase alternation, one line was green, the next purple. Stepping back a short distance, they eye blended the two lines and the picture was acceptable. At one of my jobs, throughout my long career in video product engineering, I had the opportunity to connect a three tube camera to a video monitor with direct RGB (525/30i). The result was extremely astounding. This was how I learned about how "bad" chroma encoding schemes could be.

A further detail of the NTSC I&Q signals is they were not equal bandwidth. The I signal, which was reds, yellow and orange image areas, was 1.5mhz. The Q signal which was the blues and violets, was 0.6mhz. This was done to give more detail to the brighter nature and flesh tone colors. The problem with this was a more costly receiver decoder design. Two different bandwidth filters were needed and because they were different frequency passbands, they had different delay. So yet another delay line was required in the I signal to keep it registered with the Q signal. Only a few early color receivers, like the RCA CT100 used the true I&Q system. This is why the color reproduction on a restored RCA CT100 is so good. But all USA TV manufactures including RCA as well as the Japanese soon went with the equal bandwidth R-Y, B-Y system to reduce consumer receiver costs. Most broadcast NTSC encoders continued to use the I&Q system but the advantage was lost in the later receivers that used equal bandwidth, about 500khz, R-Y, B-Y.

Very nice work, love seeing them in steam (:+}

If you spelled it "analogue", you probably had PAL. If you spelled it "analog", probably NTSC. If you only answered back, if someone spoke to you in proper French, with no accent, then definitely SECAM !

I thought PAL was 'Prey and Learn' not 'Peace at Last'.

NTSC has been jokingly --- and deservingly --- called "Never Twice the Same Colour" because the chroma phase tends to vary and the user adjustment provides no absolute reference. The Magnavox console i grew up with had both colour and tint buttons on the remote and the knobs on the set were motorised.

at 14:28, the PAL subcarrier should be specified as MHz, instead of kHz, of course.

Great poem and film evoking the working atmosphere of the Hathorn Davey engines

JC. Just for you

Not that anyone asked my opinion...but anyway...ever since I was a child I always found the Pye logo really REALLY ugly. It has "angry face" vibes about it! 😠

My dad worked at pye Birmingham nothing ever mentioned about that depot

Further to my initial comment below, it has been amazing to discover how this company contributed so much in the UK and beyond. The story of corporate take-over and sell-off is depressingly familiar and has undoubtedly gathered pace in this "global" world.

Britain can boast of so many pioneering companies in the realm of sound and vision. Pye was one of those. i still have a "Black Box" record player with its original BSR Monarch auto-changer, dating from the 1950s. Still a fine unit that produces quality sound despite the advances made in domestic entertainment over the intervening decades.

I was employed as an apprentice at Pye of Cambridge in the 60's. I lodged in St Andrews Road. We served 5 years and moved around periodically around the various company's in Cambridge whilst attending Cambridge Technical college one day a week. I remember one of the highlights of my career was working at the Broadcast TV division. We worked on an entire outside broadcast unit that was used to transmit, 'live', a concert by the Beatles. I eventually moved on elsewhere but came back some years later, in Maidenhead, to a subsidiary company that arose out of the Philips control. Dynatron Radio made high profile TVs and Audio equipment. It moved up to East Anglia where it was thought the labour would be cheaper. It became increasingly outdated in its product line although it held the prestige of supplying items to Royal households. Eventually Philips closed it down.

This was posted on my b-day Great video btw!

I'm glad if the No. 4 boiler can still run on coke. I thought that a modern gas or oil boiler had taken over, for providing steam power. I assume that the modern boiler has been plumbed in.

Analog, color.

through marriage or divorce

right on

my family

The old shop has gone. However, I am delighted to see what the old place looks like now.

Great to see you Andy after all these years. And great to know that your enthusiastic stoking can still lift those safely valves!

Chris was indeed the driving force in the original project to get the Hathorn Davey engine back in steam, doing much of the physical work himself and guiding the other volunteers