MFJ MFJ-52B User Manual

Table of Contents

MFJ-52B Deviation Meter .....................................................................2

Items with the MFJ-52B Package...........................................................2

Installation..............................................................................................3

Installation Preliminaries...............................................................3

Figure 1a-- MFJ-1270/1270B/1274.......................................4

Figure 1b-- MFJ-1270C/1276; Rev. 11.................................5

Figure 2a-- Wiring MFJ-52B in an MFJ-1270/1274.............6

Figure 2b-- Wiring MFJ-52B in an MFJ-1270C Rev. 11......7

Figure 3-- MFJ-52B Parts Layout .........................................8

Figure 4-- MFJ-52B Wiring Harness.....................................9

Preliminary Procedure .................................................................10

Installation into MFJ-1270B & 1274 TNC2 .......................11

Installation into MFJ-1270C/1274C/1276, REV.11............15

Temperature Sensors....................................................................18

Figure 5-- Enternal Temp Sensor Wiring............................18

Internal/External Selection...........................................................19

Alignment....................................................................................20

Alignment Procedure...................................................................20

Technical Assistance............................................................................22

Schematic.....................................................................................23

Parts List......................................................................................24

MFJ-52B Instruction Manual

MFJ-52B Deviation Meter

The MFJ-52B Deviation Meter is a peak audio level metering interface board, with indoor and outdoor temperature sensors and a voltmeter for the node site. The MFJ-52B also includes an optional "S"-Meter feature. The MFJ-52B developed for use with compatible TNCs. When using the MFJ-52B you will be able to tell quickly the frequency deviation of all incoming signals, as well as other data pertinent to your nodes o per atio n. T he value of d eviati on of a ll signa ls which your MFJ TNC has heard are stored in the station's "

Use the information will be displayed after each station in the heard list such as:

• The number of packets received from a station.

• How long ago the last packet was heard.

• The port on which it was heard.

• The deviation of the last valid packet in Kilo-Hertz.

If the deviatio n read ing is ove rrange a ">" character will be displayed with the deviation. Any statio n that has a deviation o f 0 will have no deviation value displayed.

You must use a

MFJ does not offer this EPROM, so it must be obtained from some other source. You can get a copy of the X-1J2 or later software with the instructions

for burning an EPROM from your local amateur BBS or from Buck Rogers, K4ABT.

MHEARD

TheNet X-1J2

command to display the heard list. Several pieces of

or later firmware EPROM with the MFJ-52B.

or later firmware for the TNC2, and

heard list

Items with the MFJ-52B Package

The MFJ-52B package comes with the following items listed below. Please check the list below, against the actual package contents. If any items are missing, please contact MFJ Enterprises for the missing items.

• MFJ-52B Rev 0 PC board

• An 8-pin IDC molex plug with five (5) wires attached.

• A 6" piece of violet 24 gauge wire

• One 6-32 x 1/4" screw

• A spacer for early TNC's that don't have one by the CPU

MFJ-52B Instruction Manual

Installation

In the Installation section of this manual, we will discuss the Installation of the MFJ-52B into the particular TNC that you have. Please pay very close attention to the Installation steps to ensure the Installation is done porperly.

NOTE: U4

is not populated on the MFJ-52B, and will be used in future

applications.

Installation Preliminaries

Do not attempt installation of the deviation board until you have the X-1J2 or later EPROM. The MFJ-52B must be used with the TheNet X-1J2 or later EPROM, otherwise, the Deviation Meter circuitry is of limited use.

For this installation to be done properly, you will need the following items:

1. A working MFJ-1270/1270B/1270C/1274/1274C/1276 TNC

2. The MFJ-52B package, containing: The MFJ-52B board An 8-pin plug with five (5) wires attached. Please refer to Figure 4. A 6" piece of violet 24 gauge wire for MFJ-1270/1270B/1274 TNC2 models. One 6-32 x 1/4" screw A spacer for early TNC's that don't have one by the CPU

3. The X-1J2 or newer firmware EPROM.

A low wattage

5. Rosin core solder

6. A #1 Phillips head screwdriver

7. A clean, organized, static free work area

: Throughout this instruction we will refer to Figure s 1a or 1b, as well

NOTE

as Figures 2a or 2b. These different figures are pictorial diagrams of different MFJ TNC models. Please be sure to use the proper diagram to find the different point references mentioned in this instruction.

Please follow the installation instructions carefully.

: From this point forward in this instruction we will make reference to

NOTE

the X-1J firmware. This requirement has changed. The firmware requirement is still

X-1J2 or later

soldering iron (15 to 25 watts)

DOES NOT

mean that the firmware

TheNet