MFJ MFJ-416 User Manual

MFJ-416 Instruction Manual

IMPORTANT NOTICE

Some versions of the MFJ-9406 require a minor change on the main pc board before installation of the
MFJ-416 CW adapter. To determine if this change must be made to your transceiver, locate R54-­about 1" to the right of HDR1 (HDR1 is the header where the CW adapter plugs in).

[ ] If no part is installed at R54 on your MFJ-9406 pc board, than you must make the modification
outlined in this sheet.

[ ] If a 4.7 uH molded choke is installed at R54 on your MFJ 9406 (yellow, violet, gold, silver), then
disregard this notice and proceed with CW adapter installation.

Modification:

To modify your MFJ 9406, find the 4.7uH molded choke included with the CW adapter kit (yellow,
violet, gold, silver). Install this choke, following the diagram below. The choke is needed to
complete the key-line connection between your CW adapter and the MFJ-9406 balanced
modulator. Without it, your transmitter will not generate RF power when the key is
depressed.

Be sure to keep chok e leads as sh ort as possible, and position t he body of the choke cl ose to HDR2.
This completes the modification, and you may now proceed with normal installation of the
CW adapter.

Note: Do Not attempt to install the 4.7 uH RF C at R54 on your circuit board.

MFJ ENTERPRISES, INC.

300 Industrial Park Road

Version OA

Starkville, MS

39759

Tel: [phone] Fax: [phone]

USA

COPYRIGHT ® 1996 MFJ ENTERPRISES, INC.

MFJ-416 Instruction Manual

MFJ-416 CW Adapter

Introduction: The MFJ-416 adapter le ts you commun icate on CW usin g the MFJ 940 6. No mode
selectio n is neede d-simply tune in and start send ing. Semi-QSK switching activates the transmitter and
in se rt s t h e c or re ct fr eq u en cy - of fse t (o f fse t ma y b e ad ju st ed t o preference by resetting an internal
trimpot). The MFJ-416 works with manual or semia utomatic k eys, and with mo st electronic k eyers. A
built-in sidetone generator provides audible feedback. The CW note generated by the MFJ-9406 is Al
carrier, not an audioder ived tone. C ontrol gates ar e ti med to ensure st rong first-character attack,
chirp-free offset switching, and comfortable QSK-hold time. FET cont rol gate s prevent ada pter
interaction with the MFJ-9406's normal SSB operation.

Installation: The diag ram bel ow illu strate s how to instal l your adap ter. Simply slip th e ad ap te r bo a rd
socket onto the 4-pin header at the rear of the transceiver's main pc board, as shown. Secure in place with a
#6 screw, using the mounting stud located at the rightrear corner of the main board. Tack-solder the
attached wire lead to the right-hand pin of the radio's

Fine Tuning

Sidetone: If you wish to use the sidetone g enerator built

into

control

your electronic keyer, remove the shorting

pin from HDR1 on th e adapter board. This will d isable the sounder.

4