80th Anniversary of BBC TV preview

[Amrad]

What does 'cap' mean?

Regards,

Dave.

[Nick]

Bandwidth cap maybe? Video eats bandwidth - if you are limited by your ISP to your total download capacity a month, media-heavy sites can eat that in no time.

[ppppenguin]

Something that doesn't afflict us too badly in the UK where low cost unlimited broadband deals are commonplace. Mike lives in the Republic of Ireland, in a rural area where internet connectivity is poor and good deals not so readily available.

[Mike Watterson]

I'm on a 10.2GHz / 10.65 GHz Duplex Fixed wireless link. It's reliably 1Mbps up and 7 Mbps to 8Mbps down so far better than average DSL of about 128 k to 256K up and 3Mbps to 6Mbps down (depending which part of UK or Ireland). Cable here is 100Mbps to 400Mbps and 1T byte (1000G) to 4 T byte cap, but I'm 6km away from it. Fibre will be here next year, but at over £50 a month I won't be able to afford it. My Wireless link is very cheap and supports two carrier grade geographic phone numbers, so I have no phone line (rental is about £25 a month before you add DSL or phone calls, the DSL would be only about 384K up, 5Mbps down due to exchange distance.

Even in UK there are many people with only mobile (which usually has a cap even if it claims to unlimited).

No-one actually really offers unlimited. Most UK has a "fair use provision" and about 500GByte to 2 T Byte. I have a 60G cap, but three of us use the connection, so that's 20G each.

Very many USA Broadband users are charged per Gbyte.

Everyone in reality has a "cap".

Cap isn't just "downloads", it the sum of ALL traffic, up and down, of every kind. I used to work in a senior technical role in an ISP. It's absolutely needed to main speed as various parts of the system have contention, and it would not be fair for greedy people to make the connections run at 1/2 to 1/5th speed for average users, which is what happens with "true unlimited" or no cap. To maintain speed, even 4G ought to have a 1G cap. Three is the most irresponsible mobile seller with high caps and price of data subsidised by voice. It makes investment in fixed broadband difficult. They don't really make profit in UK or Ireland as the Hong Kong parent wants to build market share.

[ppppenguin]

Another bit of celebration, using footage from "Television Comes to London" along with pretty accurate captions:
http://www.bbc.co.uk/news/magazine-37837336

Odd that there isn't a mention of tonight's programme on BBC4. It's at 2100 this evening and lasts 90 mminutes.

I'm off to AP this afternoon for an event of some kind. Not sure exactly what's happening but I was invited so I'll go. It's a nice day so I may walk the 3 or so miles. There are events this evening for which tickets can be bought. Not planning to go.

[chriswood]

Well done Jeffery on your guest appearance did I spy an Aurora in one shot, so I assume they fed you 625 line for the TV 22, great pity they did not borrow a 1936 set.
Chris

[ppppenguin]

Thank you. Yes, I brought along an Aurora. At least they showed the Museum's Marconi 702 and explained that the TV22 was only 65 years old.

[Murphyv310]

Hi.
I thought the program was well done. It did lean heavily toward the mechanical system though and how they were trying to replicate Baird's system, a good effort though.
In between playing with a SE valve amp I had the Ekco TC302 on for a good few hours yesterday and watched the whole program on it. I also did two 6 minute videos off screen and once cobbled together will upload them onto you-tube.
The set performed faultlessly and after an hour the emission on the CRT came way up giving a nice bright picture and better focus, It'll be re-housed in the workshop today once I get a lift with it.

[Murphyv310]

Hi.
In retrospect the program could have mentioned that other than the break due to WW2 the 405 line system served us up to 1985, a massive achievement for a pre-war system and something not to be forgotten.
They also should have mentioned that the 240 line mechanical scanned system as proposed produced a very annoying flicker, far more objectionable than on moving scenes with the interlaced 405 line system.
Very little was mentioned about how the 405 line system was devised and one name was not heard..... the very great Alan Blumlein, a serious omission.
Surely a set closer to 1936 could have been found other than a TV22 or was it a 12?

[ppppenguin]

At Ally Pally yesterday afternoon. The photo shows Lily, the 92 year old lady who appeared on TV in 1936 and also in last night's programme. Also shown are Russell's Marconi 702 and Iain Baird.

The 702 came from the Bennett-Levy auction at Bonhams a few years ago. The CRT is the best pre-war 12" EMI I have seen. This set was restored by Mike Barker. It needed several transformers and chokes rewinding. The 405/240 switch has been replaced, along with the the relevant components that had been removed. It was common practice for the 240 line capability to be removed from those few sets that had it originally. The set now works very well on both 240 and 405. The 240 line pictures were supplied by an early Aurora multistandard converter that predates the SCRF and World converters. This converter has no modulator so an external modulator (actually part of a Dinosaur converter) was used.

For those who are wondering, making 240 lines 25Hz progressive scan from 625 50Hz interlaced needs a framestore. The SCRF converter doesn't have one.

The 702 attracted a lot of attention. It was running for most of the time from about 2pm to 10pm without a hiccup.