. The Bell System technical journal . hown in Fig. shows the weights of solder balls or discs and theposition they should take on crystals having frequencies up to about onemegacycle. It should be noted that the chart covers .0063 phosphor 8Principles of Mounting Quartz Plates, R. A. Sykes, , April 1944. 254 BELL SYSTEM TECHNICAL JOURNAL bronze wire. For any other diameter, d, of phosphor bronze wire, the newdistance X = X /: dU063 Earlier, it was mentioned that the supporting wires for the plates wereformed with one or two bends. In addition to the function of suspensionthese be
. The Bell System technical journal . hown in Fig. shows the weights of solder balls or discs and theposition they should take on crystals having frequencies up to about onemegacycle. It should be noted that the chart covers .0063 phosphor 8Principles of Mounting Quartz Plates, R. A. Sykes, , April 1944. 254 BELL SYSTEM TECHNICAL JOURNAL bronze wire. For any other diameter, d, of phosphor bronze wire, the newdistance X = X /: dU063 Earlier, it was mentioned that the supporting wires for the plates wereformed with one or two bends. In addition to the function of suspensionthese bends also introduce changes in impedance along the wire thus mini- LOCATION OF WEIGHTS ON MOUNTING WIRES OF OUARTZ CRYSTALS TO SUPPRESS WIRE VIBRATION DISTURBANCE NOTE: Information shown is for mil Phosphor Bronze Wire (For mil P-b wire, weight should be multiplied by .50 and located at .75X) For 5 mil P b wire, same weight should be located at .89X For 8 mil Pb wire, weight should be multiplied by IR and located at M2X Weight. 30 40 50 60 70 8090100 200 300 400 500 600 FREQUENCY • KILOCYCLES Fig. —Graph for determining placement of weights on wires for damping vibration. mizing the possibility of trouble due to wire resonance. The use of a greaternumber of bends in the wire would tend to accomplish the same result asthat of weights. However, the use of weights is considered more practicaland has been adopted. As a result of this change, it is possible to employwire supports having only one bend in virtually all crystals. In low-frequency crystals (below 2 kc) where the wave-length of the flexural wavein the wire is relatively long it is unnecessary to use weights since the wirelength can be controlled adequately by the termination of the support wireat the straight. Depending upon the frequency, the desired length of wireis obtained by using either two or three direction bends. PLATED QUARTZ CRYSTAL UNITS 255 Housing of Crystal Units For the pressure-type
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