Graham-ophones

Links

ARTY GB (1) copy Zwarteschijf

Various Parts

Ken Priestley

Leather cloth

F R Ratchford J Hewitt

Diaphragms

Meadows and Passmore

PLEASE NOTE:

I DO NOT SUPPLY

ANY PARTS

I'M MERELY

A COLLECTOR.

Speed Calibration

By speed calibration is meant the process of making adjustments to the gramophone such that the speed of the turntable and that indicated on the speed plate are the same.  Any work on the motor will almost inevitably result in a need to recalibrate the speed.  Whilst the same in principle on all motors i.e. setting the relationship between the pad that contacts the governor plate and the pointing arm/knob on the motor deck, is common to all motors the actual means of doing it varies from manufacturer to manufacturer.  The video on the Garrard Motors page includes information on calibrating the speed on some Garrard motors.

 

On this page there are 4 videos.  The first on Speed Measurement and the second on Speed Calibration on HMV Portables.  This latter information is also useful on other HMV models that use the same systems.  The third video I have added as more and more when I restored gramophones I actually found little speed variation between measuring the speed on the spindle compared with measuring the speed when a record was being played.  As this seems counterintuitive I added this video to show how on two well maintained gramophones this has shown to be true.  The final, fourth video looks at an HMV speed tester that came with an auction win.

 

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