[78-L] When is a microgroove not a microgroove?

[David Breneman]

 From: David Lennick <dlennick at sympatico.ca>

>I have 4 7-inch 78s pressed (uncredited) by Decca, given as premiums by the 
>Quaker Oats Company or something like that..the theme and 3 stories in the 
>Sergeant Preston of the Yukon series, issued in 1952. You would think they were 
>microgroove, but a .7 stylus gives a very hissy output..I thought this was poor 
>pressing material, but I tried a 2.0 mil truncated elliptical stylus and the 
>sound was perfect. Discs are near mint, so this doesn't seem to be a matter of 
>the discs having been chiseled out. How come this, how come?


Weren't the 7" 78s from the 50s and 60s, such as children's records, also
cut with 3 mil grooves?  As a kid, I was taught to always use the 78
stylus on a slip-over cartridge for any 78, no matter what the age.