1. No cross circuit is allowed in the printed circuit. For possible intersecting wires, it can be solved by "drilling" or "winding". That is, have a lead come out of the gap under the pins of other resistors, capacitors, and transistors; or use jumpers to simplify the design to account for cross-circuit issues.
2. Resistors, diodes, tubular capacitors and other components have two installation methods: "vertical" and "horizontal". Vertical refers to the installation and soldering of the component body perpendicular to the circuit board, and horizontal refers to the installation and soldering of the component body parallel to and close to the circuit board. Different mounting components have different hole spacings on the printed circuit board.
3. The grounding point of the circuit of the same level should be as close as possible, and the power filter capacitor of the current level circuit should also be connected to the grounding point of the level. In particular, the base and emitter grounding points of the transistors of this stage should not be too far away. The circuit using this "single-point grounding method" is stable and not easy to self-excite.
4. The general ground wire must strictly follow the first-order principle of high frequency, intermediate frequency and low frequency, and follow the order from weak current to strong power. In particular, the requirements for the arrangement of the ground wires of the inverter head, regenerative head and FM head are more stringent. For high-frequency circuits such as FM heads, a large-area enclosed ground wire is usually used to ensure good shielding.
5. High-current leads (common ground wire, power amplifier power lead, etc.) should be as wide as possible to reduce wiring resistance and its voltage, and reduce self-excitation caused by parasitic coupling.
6. High-impedance traces should be as short as possible, and low-impedance traces should be as long as possible. High-impedance traces tend to ripple and absorb signals, making the circuit unstable. The base trace of the emitter follower and the grounds of the two channels of the recorder must be separated, each channel forming one way until the end of the function, like a bidirectional ground.
