Quiz on odd records

What do you know about odd records?

1. Beside the Westrex 45-45 system, what 5 other methods were used to record stereo on records?

2. What record size was the smallest ever commercially released?

3. What record size was the largest ever commercially released?

4. What feature of early LP records was eliminated by the mid 1950s?

5. An acoustic phonograph device with a plastic tape between two spools with phonograph grooves cut in it was manufactured for many years. What was it used for?

6. Glass was at one time used as the base for cutting a lacquer master. Why?

7. What materials were used to make styli before diamond?

8. A stylus was made with two .3 mil hemispherical tips placed with centers .1 mil apart, with a gap between them. What was it for?

9. I mentioned the records with maps pressed inside used to aid POW escapes during World War II. But they were based on another technology already in use at the time. What was it?

10. Why are most vinyl records black? It's not just for looks.

What do you know about odd records?

1. Beside the Westrex 45-45 system, what 5 other methods were used to record stereo on records?
-- 1932, one groove on each side of the record
-- 1932, one channel vertical, the other channel lateral
-- 1952, two grooves, one running from the rim of the record to halfway in, the other groove running from halfway in to the center label
-- 1952 Radio frequency carrier superimposed on audio with difference between left and right channels
-- 1954 two grooves next to each other

2. What record size was the smallest ever commercially released?
-- 3.875" (nominally 4"), Philips Hip Pocket Records.

3. What record size was the largest ever commercially released?
-- 20" Pathe 120 RPM records.

4. What feature of early LP records was eliminated by the mid 1950s?
-- The eccentric trip groove, long used with 78s, was replaced with a circular trip groove, because the eccentric groove threw the stylus out of the groove.

5. An acoustic phonograph device with a plastic tape between two spools with phonograph grooves cut in it was manufactured for many years. What was it used for?
-- Talking dolls

6. Glass was at one time used as the base for cutting a lacquer master. Why?
-- World War II shortages

7. What materials were used to make styli before diamond?
-- Steel, cactus thorn, chromium steel, chromium, tungsten, osmium, and sapphire

8. A stylus was made with two .3 mil hemispherical tips placed with centers .1 mil apart, with a gap between them. What was it for?
-- Test-playing record stampers

9. I mentioned the records with maps pressed inside used to aid POW escapes during World War II. But they were based on another technology already in use at the time. What was it?
-- Picture discs

10. Why are most vinyl records black? It's not just for looks.[/quote]
-- The carbon black lubricates the stylus-groove interface

The smallest record size commercially released? I believe that would be the commemorative copy of a record originally made for the Queen Mary's Doll House gramophone.




From: http://www.earlytech.com/common/show_it ... =708900865


The record was 1& 5-16th inches in diameter. In spite of the tiny size, it can be played on a conventional gramophone! This, of course, was not a regular catalog item, but was, nonetheless, sold to the general public.

Also, see -- http://www.victorianstation.com/interior.html

7. What materials were used to make styli before diamond?
-- Steel, cactus thorn, chromium steel, chromium, tungsten, osmium, and sapphire

Diamond styli were around long before chromium steel, chromium (were pure chrome needles ever made???), tungsten and osmium. Edison Blue Amberols were played with a diamond stylus as were Diamond Discs.

Regards, J.