The designer should be aware that when it is inappropriate

to lay out a PC board for the sake of just a few circuits, there

is another technique which is even better than a guard ring

on a PC board: Don’t insert the amplifier’s input pin into the

board at all, but bend it up in the air and use only air as an

insulator. Air is an excellent insulator. In this case you may

have to forego some of the advantages of PC board

construction, but the advantages are sometimes well worth

the effort of using point-to-point up-in-the-air wiring. See

Figure 6

20019321

(Input pins are lifted out of PC board and soldered directly to components. All other pins connected to PC board.)

FIGURE 6. Air Wiring

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