Does the MFJ-1984MP need a tuner? I put it to the test.

Discussion in 'Amateur Radio News' started by K5QBF, May 26, 2021.

ad: l-rl
ad: l-BCInc
ad: L-MFJ
ad: Subscribe
ad: Left-3
ad: abrind-2
ad: Left-2
  1. K5QBF

    K5QBF XML Subscriber QRZ Page

    So I have been using this antenna for a while and finally wanted to post a video on it. Now, I'm no YouTube pro, but I wanted to demonstrate just how resonate this antenna is without the use of a tuner or counterpoise or ground wire. There was a small issue at towards the end of the video that I could use some feedback on.

    73

     
    KB2QQM, W6CAT, VA7RJP and 14 others like this.
  2. K5QBF

    K5QBF XML Subscriber QRZ Page

    Follow up video to come with input from viewers. I like to test!
     
    NA4RA and K4FMH like this.
  3. W4DXL

    W4DXL XML Subscriber QRZ Page

    Good job, I like the fact you got right to it and didn't come off like an expert. We're all just learning and that makes it fun! 73 and thanks!
     
    KN4RWR, KI4ZUQ and K5QBF like this.
  4. W3AMT

    W3AMT Ham Member QRZ Page

    Very good job. Great Video and info
     
    K5QBF likes this.
  5. K5QBF

    K5QBF XML Subscriber QRZ Page

    Thank you, I am new to this Youtube stuff. :)
     
    NA4RA likes this.
  6. K5QBF

    K5QBF XML Subscriber QRZ Page

    Thank you! I appreciate the feedback.
     
  7. KE0N

    KE0N XML Subscriber QRZ Page

    Great video, thanks for posting!
     
    K5QBF likes this.
  8. WB4JHS

    WB4JHS Ham Member QRZ Page

    Great job on the video and it look like you were in Orlando Florida!

    But for my EF Dipoles are usually mounting the box up as high as possible and it slopes down and I’m curious if I’m doing it wrong that I have palm trees in the back of my yard and I run the coax up about 40 feet to the box and then slopes down toward the lake.

    when we go camping at a cabin I take a fishing pole and a 3 ounce sinker and launch it over a tree and put the box up 45 feet and slope down and usually if I can hear people I can work him worldwide with 10 to 20 W.

    interesting the tuner in the ICOM 7300 seems a bit finicky but the same antenna with the Xiegu G90 Is a match everywhere! Sometimes the 7300 won’t turn on 80 m and I have to use an outboard tuner. Not a problem or complaint. Keep up the experimentation brother! I’ve also found on 10 m it just seems to work better the higher the antenna.
     
    K5QBF likes this.
  9. K5QBF

    K5QBF XML Subscriber QRZ Page

    So for a dipole you want to mount the feed point about a wavelength above the ground in order to keep your impedance at around 72ohms if you are feeding it at the center. As you move closer to the end of the antenna the impedance will start to go up. For an end fed the feed point impedance is around 2000-3000 ohms so you need a matching unit to bring the impedance closer to 50 ohms. For an end fed that is cut to be resonant on a specific frequency you need to use a 49:1 UnUn. This brings the feed point impedance close to 50ohms.

    So height of the feed point is more important on the Dipole. As far as the tuner, I think the G90 can do a 10:1 match where the 7300 can only do 3:1.
     
  10. M7BLC

    M7BLC Ham Member QRZ Page

    My next antenna is going to be a home built version of this type of antenna (I need to keep the cost down !) so good to see your experience of how it works. Great stuff.
     
    K5QBF likes this.

Share This Page