HamComm Basic Hardware Interface Schematic


Construction Notes:

  1. Layout is not critical and assembly method is left to discretion of builder. Point to point wiring, wire wrap, printed circuit, "dead-bug" methods, etc. will all work equally well.

  2. Pay particular attention to the polarity of diodes (D1 - D7) and electrolytic capacitors (C2 - C3). Similary, ensure that IC U1 and transistor Q1 are wired correctly.

  3. Connectors J1 and J2 are convenient, but not a necessity. You could just as easily combine these two connectors into one, or alternatively, hardwire the ends of the transceiver cables directly to your interface circuitry.

Click here to see the Parts List for the circuit above.

 For those of you who are primarily interested in a receive-only capability, Ron Wilson, WB5NBQ, submitted the graphic below which shows how a standard Radio Shack prototyping board can be used to build a subset of the basic interface small enough to fit in the hood of a DB25 connector. I haven't tried it, but it ought to work just fine provided that the host computer uses a DB25 connector for its RS-232 port. It if doesn't, try a DB25 to DB9 converter plug.

Ron - many thanks for your contribution - its very professionally done and should be of great interest to many readers of this home page.


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