Building a HF Amplifier Project page 2

  Figure 3 shows the PCB after the layout has been sketched on the tinned copper surface using a red felt tip pen. There is no attempt to produce intricate artwork, just the simple functional areas that are required to make the connections. At a later stage two links are added to complete the amplifier circuit.

Figure 3

[Photograph of marked PCB]

  Next, the PCB is firmly clamped to the working area to ensure that the "finger count" remains constant. The outlines of the areas coloured in red are then carefully scored with a craft knife and the unwanted copper lifted with a soldering iron. After cleaning with Isopropyl Alcohol, the PCB appears as in Figure 4. The result is a bit scruffy, but for an "A" model it is adequate.

Figure 4

[Photograph of PCB with copper trimmed]

  The PCB is now ready for loading with components and this is best performed before fitting the PCB into the FLEXI-BOX as in Figure 5. With so much reflective surface, it is difficult to get a clear photograph, but the black surface mount components can just be seen.

Figure 5

[Photograph of PCB with components mounted]

  The two links (with red insulation) are also fitted at this stage.

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