NHRC-2 User Guide
NHRC-2 Assembly Guide
Page 1
3/16/2000
Copyright © 2000, NHRC LLC
All Rights Reserved.
NHRC-2 Repeater Controller
Assembly Guide
Rev D PCB only
The NHRC-2 Repeater Controller is a fairly simple project to build. Minimal electronic
experience is required. Assembly time should be around 1 hour.
1. Organize your parts as per the Bill of Materials. All resistors in this kit are mounted
vertically on the PCB. You may want to form the resistor leads ahead of time. Simply
bend the resistor lead over. (Hint: Try to keep the color code bands consistent top to
bottom throughout the board, oriented such that the tolerance bands of the resistors all
face in the same direction). Note that pin 1 of many components is denoted by the square
pad on the PCB. You will be working from your parts list and matching components
from the parts list to their appropriate location on the PCB. As you install a part check it
off on your parts list. You can also use the “Board Layout” image located on page 2 of
your User Guide as a reference for parts placement.
2. Insert the capacitors into the PCB. Be careful to install the polarized caps correctly. The
square pad always goes to the positive (+) lead of the capacitor. Capacitors such as the
0.1uF bypass caps are non-polarized and do not have a square pad. They may be inserted
either way. (Note: Double check your work, tantalum capacitors may explode upon
power up if they are inserted backwards. Be careful not to mix up C20 (33pF) with any
of your bypass caps, they look similar.)
3. Insert the resistors. The PCB silkscreen has a circle around the pad that the resistor body
will sit above and a line from the circle indicates where the other lead goes. Be careful to
match the reference designator to the proper component location. If in doubt find the
component in the schematic and use an ohmmeter to identify the component location in
question. Some reference designators may be crowded among other reference
designators and may have a line drawn to the proper component location. (Note: Pay
special attention to the placement of resistors R4 and R11. Resistor R4 is located next to
C3 and R11 is located next to C8.)
4. Install the voltage regulator, U4 (LM7805) and power MOSFET Q6 (IRF510). All of
these components are installed with the heat sink surface facing out from the board.
(Note: These parts should not require mounting to a heat sink.)
5. Install the other transistors and FET's. Q2, Q3, and Q4 are PN2222, Q1 is an MPF102
JFET, and Q5, which is a 2N3906.
6. Install the zener diode, D1 (1N5226) so that the cathode (the end with the band) goes into
the square pad. (Note: Zener diode D2 (1N5240) does not need to be installed.)
