August 10, 1973

HD-20                                           Bulletin No:

Crystal Calibrator                                      HD-20-1



                               Battery Shorting To Case



In some of the older HD-20 calibrators, there is a possiblitity of the

battery sliding in its clamp, shorting to the case.  This can be

eliminated by installing insulator paper [PN 75-93] on the inside of the

case, directly off each end of the battery. [2 required].

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Thats everything I hold up to 1985 that covers the HD-20 Crystal

Calibrator.