MFJ 490 Keyer to FT-818/818ND

Discussion in 'General Technical Questions and Answers' started by G0TUE, Apr 15, 2021.

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  1. G0TUE

    G0TUE Ham Member QRZ Page

    Hello Friends.

    My first question is does anyone have this combination for their setup?

    The 490 keyer has a Phono RCA female socket output
    the ft-818 has a 3.5mm stereo 3 pin input, ot 3.5mm mono 2 pin connector
    for a straight key.

    I cannot seem to get the keyer to work, I have other keyers and they work, I have used the
    internal keyer and that works, but the mfj 490 just does not, it's brand new, B/Day present
    from the wife.

    I have read the 818 manual and the keyer manual.

    I have made 3 different leads, I think I may be missing something with either the keyer or
    a menu setting in the 818, but I have drawn a blank.

    Does anyone have this combination? or similar to help with either menu settings or lead configs.


    Ray g0tue
  2. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    First, the obvious: Does the speaker in the MFJ-490 work and produce tones corresponding to using the paddle? If you select TUNE on the keyer, does it key the Yaesu?

    If you have "other keyers and they work" (with the FT-818) then obviously you have the Yaesu set up for a STRAIGHT KEY connection, which would be required to use any kind of external keyer.

    You do have to change a menu setting to use the internal FT-818 keyer...but if you've tried "other keyers" with it and they work, then you must know that!
  3. G0TUE

    G0TUE Ham Member QRZ Page

    yes the keyer with a bencher paddle fully operational, everything works fine - no issues on the keyer.

    I have small keyers which connect into the 818 using the stereo 3.5mm jackplug.

    also the 818 internal keyer works with just the bencher key or any other paddle via the 3.5mm jackplug.

    I have made leads Phono RCA to mono 3.5mm jackplug as suggested for a straight key setup.

  4. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Suggested by who?

    That's not what Yaesu suggests, and also not what works.

    You use a "stereo" (3-circuit) plug either way, for a paddle or a straight key. Just with a straight key it's wired differently as shown:
    ft-818 key.PNG

    Use the same 3.5mm 3-circuit plug for a straight key, just don't use the center "ring" connection.

    A 2-circuit plug may not work at all, even though you're using only two wires. It's a matter of plug barrel dimensions.
  5. KG7WGX

    KG7WGX XML Subscriber QRZ Page

    I believe there may be some confusion in terminology. For example, using "keyers" to describe paddles and "jackplug" to describe a jack. Also, there may some confusion in how many jacks exist. The FT-818 only has one, according to the manual. Also, the plug's wiring has to be consistent with the FT-818's menu settings for how it should use the jack. (There is a 3.5mm mono jack on the side of the FT-818 for headphones, not for a key.)

    To use an external keyer, the FT-818 menu has to be set to "straight key". This may not make sense, but it is what the external keyer "looks like" to the FT-818. Conversely, if you want to go back to using the internal keyer, you have to not only replace the external keyer with paddles but also change the menu so the internal keyer is enabled again.

    I believe the problem is the FT-818 manual, which mentions straight key or external keying device use, but then entirely skips describing how to set it up. That section covers CW normal/reverse, weight, pitch and how to use BK-IN for off the air practice. Nothing about straight keys or external devices.

    I believe all you have to do is follow the manual's instructions on how to get to Function Row 10. Tapping button C toggles the internal keyer on/off. When it is on, there is a > symbol shown. If the internal keyer is working with paddles connected to the key jack, the internal key is enabled.

    So, if you navigate to Function Row 10 and tap button C, the > symbol should disappear. Now the FT-818 should work with your external keyer, provided the RCA-3.5mm cable is wired correctly.

    It must be wired as shown above in a previous post, center of RCA to "tip" of stereo plug, ground of RCA to "shield" of stereo plug. The "ring" contact on the stereo plug is not connected (N/C).
  6. N3PM

    N3PM Ham Member QRZ Page

    Look closely at the 3.5mm stereo plugs and make sure they are fully seated in the rigs jack. Some plugs just don't make it.
    Mike N3PM
  7. AA5MT

    AA5MT Ham Member QRZ Page

    Take a screwdriver across the Radio plug, and the radio sidetone should sound, and the radio may key. This confirms that the radio is set for straight key operation. When you get to this stage, you only have the keyer to worry about. It should function as a straight key if the radio menu is set up right. This now isolates the problem to the keyer. Check the keyer jumper for type. It may be in the grid type keying mode. Move the jumper for normal keying and the radio should be triggered by the keyer.

  8. KG7WGX

    KG7WGX XML Subscriber QRZ Page

    There is one other thing, which is that this keyer can have its output disabled to permit code practice without disconnecting cables.

    It might have been accidentally disabled.
  9. G0TUE

    G0TUE Ham Member QRZ Page

    Thank you for your replies, I was in bed early, early shift beckons, 05:00 start, but I will have another
    dabble this afternoon, One of the plugs has already failed, was connected to tip, cheap plugs, mass produced :)

    I know it will be something simple because everything works just not when connected lol
    bit like the sketch, think it was Les Dawson, I can play every note but just not in the right order.

    Little menu's for old eyes on the 818.

    But I thank you all, and I will update this thread later today after my shift.


  10. G0TUE

    G0TUE Ham Member QRZ Page

    I have made up another lead - still nothing
    checked memories and adjusted but still nothing?

    I'm now scratching my head, I know I'm getting old but Gee!

    I think I may need to chat with someone who has this combination,
    the only other option is to disassemble it and just use the bencher key
    with the built in keyer.



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