Elecraft W1 User Manual

Elecraft • www.elecraft.com • 831-662-8345 ELECRAFT W1 Power Meter Assembly and Operating Manual E740100: Revision D, October 12

10 Turn the POWER switch OFF, then install a 9-volt battery in the holder or connect a d-c supply between 9 and 14VDC to J2 (positive to center pin).

11 Circuit Description Refer to the schematic diagrams on pages 12 and 13 . Transformer T1 is a directional coupler sampling the forward and reflected

12 Schematic Diagram, Sheet 1

13 Schematic Diagram, Sheet 2

14 Serial Interface Commands The W1 responds to commands for data supplied by the external system. Nothing is sent until a command is received by the

15 Command Purpose Request the user settings currently being used in RAM String Length 6 chars. Response X<A|P><A|P><S|M|F><S|

2 ESD-Sensitive Parts Some of the parts in this kit are sensitive to damage from electro-static discharge (ESD). Problems caused by ESD damage may be

3 Reference. Designator Description Qty Part Number R15, R21 100K (brn-blk-yel) 1/4W Resistor 2 E500006 R16 10k (brn-blk-org) 1/4W Resistor 1

4 Assembly Procedure The finished Power Meter is shown in Figure 1. We recommend you follow the assembly procedure below and refer to this figure as

5 __ R20, 24.9K 1% (red-yel-wht-red)  __ R16, 10K (brn-blk-org) __ R18, 22K (red-red-org)  __ R14, 1K (brn-blk-red) __ R22, 22K (red-red-org)  __ R

6 Position trimmer potentiometer R17 (502) on the board over the silk screened outline near RP1 and RP2 with the beveled end lined up over the beveled

7 LEAVE A SMALL SPACE FOR AIR TO CIRCULATEBE SURE NO LOOSE STRANDS ARE TRAPPED ON TOP OF THE BOARDDO NOT FILL THEADJACENT SOLDER PAD.BE SURE THE SECON

8 3. While holding the LED squarely on the PCB, wet the tip of your soldering iron with a small drop of solder and touch it to one lead and solder pa

9 i Follow ESD protection while handling the transistors and integrated circuits in the following steps (see ESD-Sensitive Parts on page 2). Either we