Background Radiation Monitor
The Aware Electronics RM60/RM70 Series

The X1W-1 design supports an optional interface for the Aware Electronics RM60 and RM70 radiation monitors. Information on the RM60 and RM70 can be found on the Aware Electronics web site. Currently, software support is only in N4XI's WXN weather server.

If you plan on using a background radiation monitor and also wish to have an interface for the the rain gauge, the rain gauge will have to be used with the outdoor sensor/interface board, the X1W-2.

These assembly steps install the necessary components to use the RM-60/RM-70 background radiation monitor and the EMP sensor interface. Those installation instructions that use parts mounted in places where a different part is called for (e.g., a diode placed where the silk-screen shows a resistor) are shown in red.

Construction is divided up into three main sections and is called for in the appropriate section of the manual. If you follow the instructions in the manual, they should bring you here to the appropriate section when required.

Section 1: Power Supply
Section 2: Main Interface
Section 3: Jumpers


Section 1: Power Supply

The following components are located in the upper left-hand corner of the board between the 78L12 and the 78L05 regulators.

Ok
Procedure
  78L09 low power 9V regulator at U13
  1 uF (105) tantalum capacitor at C15
  1 uF (105) tantalum capacitor at C16

Next


Section 2: Main Interface

Note that this procedure also covers installing parts for the EMP sensor as well. The same 1-Wire interface chip services both the radiation monitor and the EMP sensor.

5% Tolerance Resistors

Ok
Procedure
  10K, 5% (brown-black-orange-gold) at R1
  10K, 5% (brown-black-orange-gold) at R2
  220, 5% (red-red-brown-gold) at R101
  100, 5% (brown-black-brown-gold) at R4
  Solder and clip eight leads. Wear safety glasses and observe proper precautions!

Monolithic Capacitors

Ok
Procedure
  0.1 uF (104) at C1
  100 pF (101 or 100) at C24
Be certain the following cap is installed at D1!
  0.001 uF (102) at D1.
  Solder and clip six leads. Wear safety glasses and observe proper precautions!

Ferrite Beads

  Ferrite bead at L6.
  Ferrite bead at L7.
  Solder and clip four leads. Wear safety glasses and observe proper precautions!

IC Sockets

Ok
Procedure
  6-pin DIP socket at U1. Pin one (or the notch) faces towards the bottom edge of the board.
  6-pin DIP socket at U3. Pin one (or the notch) faces towards the bottom edge of the board.

Diode

Ok
Procedure
Be certain the following diode is installed at R3!
  1N4001 at R3
  Solder and clip two leads. Wear safety glasses and observe proper precautions!

Connectors

Ok
Procedure
  RCA Female Jack at J2. The fit may be a bit tight. Gentle pressure might be required to properly seat the part on the board. Take your time if this is the case.
  RJ11 6-4p female jack at J1

9V Battery Connector

If you are thinking about using a power supply instead of a battery for the EMP detector, don't. The opto-isolator is there for protection. If an external supply is used, you will risk allowing an EM discharge to possibly enter the equipment through the power supply lines or ground causing possible damage, bypassing the protection offered by the opto-isolator. Battery life is typically one to two years, depending on EMP activity.

Wires are fed to the board from the top.

Ok
Procedure
  Solder the red lead to the + hole at P7
  Solder the black lead to the - hole at P7

Next


Section 3: Jumpers

As with the ferrite bead installation, use clipped resistor leads for jumpers. Form a narrow “U” with the clipped lead and pass the two ends through the PC board. Pull the leads down snug and spread them slightly.

Ok
Procedure
  Jump Vin to +9 at P19
  Jump A to RM at P1
  Solder and clip four leads. Wear safety glasses and observe proper precautions!

RM-60/RM-70 Jumpers

These jumpers are found at JMP2 which is located right behind J1, the RJ-11 jack the RM-60 will plug into. All four jumpers are straight across, i.e., no crossing of wires.

Ok
Procedure
  A to W
  B to X
  C to Y
  D to Z
  Solder and clip eight leads. Wear safety glasses and observe proper precautions!

Next