Yaesu ft-857d RX Mod/Hidden Menu

Discussion in 'Radio Circuits, Repair & Performance' started by K4NIN, Oct 5, 2009.

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  1. K4NIN

    K4NIN Ham Member QRZ Page

    The hidden menu within the 857 is accessed by holding down buttons a,b and c while powering on the unit. My main focus in the menu was to bump up the receive on the HF side of things. The first three options are the ones I'm looking at.

    NO-001-------- HF1-RXG-----82------102-------CW
    NO-002-------- HF2-RXG-----66-------81--------CW
    NO-003-------- HF3-RXG-----81-------101--------CW

    I raised the values about 25 percent, and will test out over the next few days. There have been other posts online that have recommended boosting these values by twice the values I have set.

    Has anyone else tried this mod, and what values worked best for you? I'm looking to boost the weaker signals for DX work..... Thanks!
  2. NN4RH

    NN4RH Premium Subscriber QRZ Page

    What are you using for an antenna?
  3. K4NIN

    K4NIN Ham Member QRZ Page


    I have a couple of homebrew wire antennas I'm currenty using. The latest would be a vertical loop, in the shape of a triangle.

    I used the slingshot method to get the top up at about 35-40 feet in the trees.

    The base of the triangle runs parallel to the ground, for about 50 feet.

    It's orientation is broadside to East and West, being fed from the Southern corner, with about 40 feet of coax connected directly to it.

    The wire is the standard 14 guage stuff (solid) you will find at Home Depot.

    Checking the SWR after I got it pieced together to test, I was really surprised. I figured I would need to trim, test, trim, test....to get it resonant around 7.2.

    But somehow, (I should play the lottery today) it was close to 1:1 right at 7.2 MHz.

    As a matter of fact, I was surprised to see how "broad banded" it was.

    MHz SWR
    6.9 1.75
    7.0 1.25
    7.1 1.2
    7.2 -
    7.3 1.2
    7.4 1.25
    7.5 1.75

    14.0 1.5
    14.1 1.25
    14.2 -
    14.3 1.25
    14.4 1.5

    17M - high

    21.1 1.25
    21.2 1.4
    21.3 1.5
    21.4 1.5

    28 1.6
    28.1 1.7
    28.2 1.9
    28.3 2.2
    28.4 2.4
    28.5 2.5
    28.6 2.75
    28.7 3
    28.8 3
    .......gradual increase through 10M

    I worked my first VK station this weekend on 15M with this antenna.
    Of course it was on my TS-50...LOL....

    The other antenna is a G5RV, up at about 26 feet.....

    Thanks as always...
  4. NN4RH

    NN4RH Premium Subscriber QRZ Page

    OK. The reason I asked about the antenna is that, really, fooling around with the "hidden menu" settings in the radio is not going to make DX stations pop out of the background. If that were all there were to it, everyone would be buying FT-857Ds and modding them!

    What you're fighting is signal to noise ratio and interference from other stations. Even if you did "bump up the recieve" via the hidden parameters, you'd also be bumping up the noise and interference right along with it.

    So there's several ways to reduce noise and interference. One is to have a directional antenna. The more directional the better.

    It also can help sometimes to turn the RF gain down, and the audio gain up. If you're a CW or data operator, get one of the optional narrow 300 or 500 Hz CW filters. Sometimes turning off the AGC can make a difference.

    Also locally generated RFI can bury signal that is weak, but otherwise would be receivable in a quieter location.
  5. K4NIN

    K4NIN Ham Member QRZ Page

    Thanks for your thoughts....I don't really use CW, just voice and digital.

    The noise level was my concern as well, as it has seemed to increase.

    I have been adjusting gain down to about 50 percent to stop some of the noise on 40... Not an issue on higher bands.

    I also turned off the preamp (IPO) option on 40, based on the recommendations in the manual.. To also reduce the noise.

    You're right, it seems like I have to reduce the gain down to compensate for the noise. So, is there any benefit?

    I'm trying to wrap my head around the many variables here, and come to a happy medium...
  6. NN4RH

    NN4RH Premium Subscriber QRZ Page

  7. K4NIN

    K4NIN Ham Member QRZ Page

  8. VA3CSS

    VA3CSS Ham Member QRZ Page

    You need to be VERY CAREFUL changing things in this menu. They are set at the factory, and are specific to each and every 857 coming off the line.

    Take note of the original settings before you change them so that you can return them to where they should be if things don't work well afterwards.
  9. K4NIN

    K4NIN Ham Member QRZ Page


    Oh yes, did that first.....
  10. KA9MOT

    KA9MOT Ham Member QRZ Page

    And really, you need more then just an antenna to do a RX alignment. Fortunately you kept your original settings. Preamps cause more problems below 20M then they cure. There is just too much noise.

    Where did you find the info on your loop? I have seen allot of plans and they all look good.......I have a tall tree and was thinking about a third antenna.
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