Saturday, January 21, 2017

Quirky Keyer - The MFJ-493

The MFJ-493 has some cool tricks and some not so cool flaws

MFJ-493 "Super" Menu Driven Memory Keyer

Memory keyers do the repetitive and boring stuff

The bands have not been kind in this declining sunspot cycle and I've been sending out my call repeatedly on occasions before receiving a response.  I wanted to get a memory keyer to lessen the burden of repeatedly sending my call and to also give me opportunities to do a bit of contesting this year.

If you want a good memory keyer, the K1EL Winkeyer is the natural choice to go with, so of course, I chose to acquire a 23 year old MFJ product instead.   

Take the road less traveled and you'll find wonders or fall in a ditch, I always say

The MFJ-493 is no longer sold but you'll frequently see them available used for reasonable prices and MFJ still sells a less featured variant (the MFJ-492).

Memory keyer at the the ready

Features

Typical of many memory keyers the MFJ-493 let's you store messages in up to 8 memories of 4,000 character each using your paddle, an external keyboard plugged into the back or a terminal program via the serial interface.  If you make a mistake while entering a message you can send 8-DITS and it will erase the previous word and send the last word in the message so editing is fairly easy.  Messages can be constructed from other memories, i.e. you can store your call in Memory #1 and then use "/1" in other messages to reference your call.  Repeats and timers are available within the messages as well.

Any of the 8 messages can be sent with the press of a button, although to send messages 4-8 you switch to the second bank of memories.

I won't list all the features because I think they are relatively common across memory keyers and I've posted a link to the manual later in the post, but I will mention that I enjoyed the ability to vary the character AND word spacing sent in messages.  So you can create "Farnsworth" type messages that sound (to my ears) far more natural than the typical "squashed" sounding CW sent from most memory keyers.  I demonstrate that in the video review.   I know a contester would never want to slow down the CW sent from his memory keyer but I have different priorities.

Most of the functions are clearly visible on the front panel so you don't need to refer to the manual to operate most features.  Some of the commands are not listed on the front panel so don't totally ignore the manual.

Back panel
The back panel sports a couple interesting ports.. an external keyboard interface and a serial port interface.  The external keyboard can of course be used to generate Morse code without a paddle and can make programming memories easier.

The serial port can be used with a terminal emulator like PuTTY set to:

  • 1200 baud
  • 8 data bits
  • 1 stop bit
  • no parity
  • xOn/xOff flow control.


If you power up the keyer while it's attached to a terminal emulator you can see some interesting information:
MFJ-493 MEMORY KEYER VERSION 1.1.2C.        COPYRIGHT MFJ ENTERPRISES, 1993.
TYPE "[help]" (USING BRACKETS AND LOWER CASE LETTERS) FOR ON LINE HELP INDEX.
[help]
HELP INDEX FOR MFJ-493 MEMORY KEYER
1.  TYPE [help-program] FOR HELP ON PROGRAMMING MESSAGES
2.  TYPE [help-transmit] FOR HELP ON SENDING MESSAGES
3.  TYPE [help-setup] FOR HELP ON CONFIGURING YOUR MFJ-493
4.  TYPE [help-list] FOR LIST OF ALL COMMANDS
[help-list]
HELP-LIST INDEX FOR MFJ-493 MEMORY KEYER
[help]           LISTS GENERAL TOPICS
[help-program]   LISTS MEMORY STORING INSTRUCTIONS
[help-transmit]  LISTS TRANSMITTING INSTRUCTIONS
[help-setup]     LISTS KEYER SETUP INSTRUCTIONS
[help-list]      LISTS ALL COMMANDS
[start#]         STARTS KEYER MESSAGE NUMBER # STORAGE ROUTINE
[stop]           ENDS KEYER MESSAGE STORAGE ROUTINE
[{#}]            MARKS FILE FOR ASCII UPLOAD TO MEMORY
[send#]          SENDS MESSAGE NUMBER #
[show#]          DISPLAYS MESSAGE NUMBER # CONTENTS
[co]             STARTS KEYER COMMAND MODE
Among other commands.  There are also commands for printing out the contents of the memories.
So the keyer has a sort of built-in manual if you connect it to a terminal.  Very full featured at used prices.

Using a terminal to the keyer via the serial port also displays everything you send with your key as well as allowing keyboard (terminal) input to the memories or allowing you to send code by typing in the terminal emulator.

Lastly regarding commands.. a useful command to know that's not on the front panel, is that you can reset the 493 to factory settings by holding the menu button down while turning it on.


Cool features not seen in other memory keyers

Two functions FCC Exam Practice and QSO Practice are lots of fun.  The FCC Exam practice sends a standard FCC CW exam from back when code was required for license upgrades.  It varies up the messages but sends the standard elements required back then.  Good for practice.

But the super-cool feature is "QSO Practice". This mode performs an interactive QSO with you.

Are band conditions getting you down?  No one answers your calls?  Have a QSO with your keyer!

I'll leave the video to do most of the explaining but basically, the keyer will listen to you send CQ and answer your call and then exchange information with you answering after the turn around.  You're expected to get the call it SENDS you correct or it won't answer you back.  If you send poor CW it makes raspberry sounds at you.  It's just a lot of fun to play around with and copy.

MFJ-493 "QSO Mode" demonstration


Nits

A couple features that are completely useless are the "hand key" mode and the "semi-automatic-mode".   Once the hand-key mode is enabled you can use either paddle as a straight key but it is very unresponsive at anything over 5-10 wpm.  So keep your straight key wired into the output of this keyer.  Similarly the "semi-automatic" mode is supposed to simulate a bug, where the DITS are sent automatically but the DAHS are manual.  Well it's even worse than the hand-key mode, don't bother as it's for entertainment purposes only.

Another problem with this keyer is related to the weighting commands 'C' and 'W'.  If you have either of them set to a value other than zero you cannot accurately record a message into memory using the paddles.

I'd hoped to be able to run both my paddle and bug into the input of this keyer and switch it to hand mode when I wanted to use the bug and use it as a bug "de-scratcher" but it doesn't buffer the bug input and in hand key mode misses about a third of the DITS sent by a bug so no joy there.  I'll just keep using my old Ham-Keyer as my bug de-scratcher.

MFJ-493 Manual

Many thanks to Paul/N6MGN for sending me a copy of the manual and schematic for this keyer so I could share them.

View manual
Download manual

View Schematic
Download Schematic

So many connections

Adding this additional keyer finally made me break down and build a connection box for all my keys and rigs.  I have 4-5 CW keys on my desk at any given time and 3-4 radios.  Each of the two external keyers have female RCA jacks for output.  The Ham Keyer uses 2 independent 1/4" inputs for straight key and paddle while the MFJ-493 uses a 1/8" stereo plug for the paddle.  The Ham Keyer expects the DIT to be the tip of the plug and the MFJ (by default) expects the DIT to be the ring of the plug.

Arrrgh!

To top it off, each of my primary 3 radios expect different wiring from an external keyer.  
  • The Elecraft KX3 needs a 1/8" stereo plug with the ring terminal un-grounded
  • The TenTec Eagle needs a 1/8" stereo plug with the ring terminal grounded or a mono 1/8"
  • My TenTec Century/21 needs a 1/4" mono plug (my rig is modified, I believe a stock C21 needs a male RCA
So I took a project box drilled it for 5 phono jacks wired in various configurations for each of the rigs and keyer inputs.  I still can't leave the KX3 key plugged in when not in use because when that radio is turned off it presents a high impedance on the plug and makes the C21 think the key is down...  (nothing is ever simple) but now I don't have a bunch of 1/4" to 1/8" and stereo to mono plug connectors chained together like a box-cars on a train.


Video review

This video review demonstrates a few of the features and contains the same QSO in the video above at the end...



Summary

The MFJ-493 is a feature rich yet somewhat flawed keyer.  For the price I think it's a good buy but don't expect some of the more esoteric functions to work up to your expectations.



That's all for now

So lower your power and raise your expectations... and send your call a couple dozen times using a memory keyer

72/73
Richard AA4OO

3 comments:

  1. FB on the extra investigation into the computer connection. The MFJ-493 is pretty cool and I hope I can snag one someday. Been doing CW for a year and a half and am consumed by it! I checked your QRZ page but no email, so pse contact me so I can send you the manual.
    73 de Paul/N6MGN

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  2. Just a nit, the radio key input connectors are 1/8" not 3/8". I know you knew that, HIHI.

    ReplyDelete
    Replies
    1. Thanks Paul. Not sure what I was thinking. Fixed now.

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