At the risk of being called sad I did have a look at some 12 inch LPs to see what size the discs actually measure.

I found them to be consistently 301 - 302 mm (to the best of my measuring ability I think they are between those two limits)

I also understand that the physical size of the disc is slightly large than the original blank due to the effect of pressing (applying the pattern of grooves under pressure).

So are they really 12 inches? (305 mm) Or is that a nominal size when in fact the original blank is 30 cm?

I was wondering that - although I'm pleased to say I wasn't sad enough to actually measure one ;-)

The original debate between Steve and Erin descended into childish nonsense, which everyone I assume ignored as usual. Erins argument may have had some substance.

I am happy to be told otherwise, but it seems entirely possible that vinyl records were 30cm rather than 12 inches.

The equipment to make records have stayed the same, the process of cutting the 12" records plays a part in the final record size.

I'm quite happy with discussing this with you two, I couldn't (and can't) take BarmyBoy seriously enough to have a proper conversation without it descending into the usual stuff and turning into a comment on the US economy etc.

The facts are CD is measured metrically (the machines that make them are metric) but we tend to refer to them as 5" discs (and 3" for the obsolete mini-cd). This is true of DVD also.

Vinyl records come in 7" 10" and 12" standards and range in speed from 16 through 33 1/3 and 45 to 78. 16 went obsolete yonks ago and 78 died out in the 60's, although some 78s on 7" went on into the 70's.

The size of the records were most imporant during the days of the jukebox where the size mattered to correct function. Juke boxes of this nature started in the 50's up to today (the Wurlitzer "1 more time" is the current one).
Early records (10") were made from bakelite and would commonly shatter in the older jukeboxes.

Records have been made prior to the US and UK "going metric" and the process is still the same today.

In fact some people prefer the sound of 70's vinyl to todays but that is more to do with master tapes than production. The production remains the same.

I can't believe you actually measured one, Stan! I could have told you directly that you won't get an exact figure!

I assumed you'd recognise Erin's (John) argument technique as to the truth of the claim.




Right - can anyone tell me the speed of a compact cassette?


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If the next post is by "HevetS" then you know how the argument will "progress" from here.

Again.

"""At the risk of being called sad I did have a look at some 12 inch LPs to see what size the discs actually measure.

I found them to be consistently 301 - 302 mm (to the best of my measuring ability I think they are between those two limits)

I also understand that the physical size of the disc is slightly large than the original blank due to the effect of pressing (applying the pattern of grooves under pressure).

So are they really 12 inches? (305 mm) Or is that a nominal size when in fact the original blank is 30 cm?



American records are nominally 302 mm. German records are 300 mm. I would also think that records made in other metric countries are also 300 mm. The difference between 300 and 302 is insignificant as far as the players are concerned. But a 305 mm disc would result in some of the first grooves being missed. There is however no need to worry as no 305 mm record has eve been made.

Some people can't seem to seperate a TRADE NAME from an actual dimension and are so afraid that the actual dimension is actually different from the trade name they refuse to measure it to verify. They may have measured the records but were embarrassed to find out the truth and refuse to admit they were wrong.

Right - can anyone tell me the speed of a compact cassette?



My Stereo Cassette tape Record/Playback deck manufactured in Japan by Sharp Electronics states the cassette speed as 4.8 cm/s. Now, Steve will insist it is really something something inches per second. But remember folks, these machines are made in Japan, which is a metric country. They design and use metric instuments and measuring standards. Meaning they will convert whatever inches it might have been to metric that they can and do use and round it to a convenient number to one decimal place.

The Japanese don't give a doodle if should have been some nicety round number in imperial. They don't use imperial. They use metric and will make changes to older standards if theose older standards are not convenient for them to work with.

"""Records have been made prior to the US and UK "going metric" and the process is still the same today."""


Not always true! Record making companies like any other modernise their production over time. New technologies mean newer procedures and newer machines to do the work. Machines made in Japan and the EU will use metric to do the job. They always have and always will.

I'm sure with little effort anyone can list the names of UK companies that 40 years ago were 100 % imperial and are now 100 % metric. They may still make the same products. The only difference between now and then is computerisation of the design and manufacturung process, using metric units in the design and manufacture, and using metric hardware instead of imperial. The vinyl record industry is no exception.