A bit of stroboscopic trickery,or how to check a record player's speed.

The old trick to establish if a record player was running at the true speed was to use a stroboscopic disc.Thanks to two of my friends on here,for the first time in ages l have a disc!

Category:

Howto & Style

Tags:

• Record
• player
• turntable
• platter
• vinyl
• stroboscope
• incandescent
• lamp
• correct
• speed

[shesnailie]

The turntable of mine actually has the stroboscope and pitch controls built in. Made by Technics sometime in the 70s or 80s. Found in the wild sometime in the 90s.

[AG3304]

@shesnailie Sounds good to me.Even some fairly cheap Philips ones had this pitch control feature,it was only fitted to those with the little DC servo motor mind.This was the same sort they put into their cassettes at the time,and the odd reel-to-reel.

[Josephharpermusic]

Ya have a great voice mate. Where abouts Britain are you from? I am American, but just spent two years living in Southampton and London.

[AG3304]

@Josephharpermusic Thanks for that,l Came originally from Cornwall,now in East Sussex,about 60 miles from London as it goes.

[dunstun365]

Thats why fluerescent lights flicker which hurts my eyes.

[AG3304]

@dunstun365 Quite right.On the older London Underground trains,a special Motor-Alternator set was used to run the striplights in the cars,at 400 CPS.This was done to avoid interference to signal circuits,and those 400 CPS lights never did bother me like a normal mains one does!

[AG3304]

@clydesight l've just done the same thing with a friend's BSR deck.They always seem to need a good cleanout and relube,but now it runs spot on.The strobe readings while changing were how shall l say,erratic? :-)

[clydesight]

@AG3304 I recall a cheap Lafayette record changer I had. I did a strobe test on it and it was slow and had a bit of flutter. I took off the platter and got the main bearing racetrack out. The grease was really gooey and sticky. I cleaned it and lubed it and the thing ran on speed with no flutter that I could see. Sounded better too. It was fun to leave the strobe on and make it try and change a record, the readings naturally went wild!

[AG3304]

@clydesight l remember those things.Not much you could do with a sluggish shaded-pole driven one if it was all as free to run as it should be! Philips units with the DC motors sometimes had a pitch control on top,otherwise you'd to open it up and do it from the control module...

[clydesight]

@AG3304

In the 1960's they used to sell strobe kits for turntables and tape recorders. They came with the disc and a little neon bulb. Popular Mechanics magazine did an article telling people that if they had a regular fluorescent fixture (in those days, there were no energy saving bulbs) they only needed to buy the disc. Many kitchens were lit by fluorescent fixtures.

Problem? Only high end turntables had pitch adjustments!