Stuffing the Board - Text Version

The top silkscreen shows the value and location of all the parts. The "C" designator means capacitors and the "R" designator means resistors. The chokes (RFC), coils (L), crystals (XTAL), and IC's (U) are all marked for easy placement. Watch for the notch on one end of the NE602's and the recessed dot at pin 1 on the T4-6T broadband transformers. The diode has a black band on one end that is matched with the silkscreen.

Small components should be mounted on the board first. Start with the .001, .01, and .1 capacitors. Lay out the mica and NPO capacitors according to value and stuff them in the board.

Carefully read the resistor values, according to the colors, and place them on the board. If in doubt, use an ohmmeter to correctly identify resistor values.

Insert the diode (watch for correct placement of the black band) and the RF chokes. The RF chokes used in this kit are "modular" chokes. They can be mistaken for resistors. The chokes have square ends and a double-wide silver band on one end. RFC1 value is not critical in value (180 to 560UH OK). Most of time, RFC1 (180UH) will be larger in size than RFC2 (22UH).

Lay out the electrolytic capacitors. Electrolytic capacitors are polarized, which means they have a negative and a positive wire. If the negative wire is marked, the other wire is the positive. The positive wire is also the longest of the two wires coming off the capacitor. The positive wire should be placed where the "+" mark is on the board. Be sure to double check that the "+" wire on the capacitor is toward the "+" side on the board.

The two "VAR" (Variable Trimmer) have a flat side that matches the silkscreen. The third variable trimmer is installed at C32, next to C35, between the VFO coil and U1. The round side of the trimmer goes to ground.

Look closely for the notch on the NE602's and the recessed dot on the T4-6T coils and match them to the silkscreen. The crystal layout is universal. Use the two pads inside the oval that fit your crystals the best.

The audio amplifier (TDA2002) and the trap can only go in one way. Do not insert the TDA2002 all the way. Leave it sticking up as far as possible to give plenty of room for a heatsink. Mount the heatsink on the TDA2002 with the screw and nut supplied with the kit. The five (5) volt regulator (7805) must have its front (lettering and numbers) located as shown on the silkscreen.

The top (with the lettering and numbers) of the MMIC faces upward. Place the long lead of the MMIC in the proper direction as shown on the silkscreen. For easy installation, bend the short pins around the lead of a resistor or hook-up wire. Bend the long lead half way down. Be careful! Drop this part into the carpet and it might disappear!

Wind the toroid coils. You may want to mark the primary leads of the input toroid with a piece of tape to keep them separate from the secondary winding. Using two different colored wires will make winding the bifilar secondary a lot easier. Use the tables in step 6 to determine the number of turns and tap locations of the coils. Make the taps about an inch long for easy installation on the board.

When finished, mount the coils on the board. See the illustration in Step 7. After soldering, the VFO coil should be attached to the board with some silicone rubber sealant. This will prevent the coil from vibrating and causing frequency changes. Also, the toroid can be easily removed by cutting the silicone with a razor blade.

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Last Update: 05/09/97
Web Author: David White, WN5Y