Yaesu FT-991A antenna tuner into Amp

Discussion in 'General Technical Questions and Answers' started by N8FVJ, May 15, 2019.

ad: L-HROutlet
ad: l-rl
ad: Subscribe
ad: DLSpec-1
ad: L-MFJ
ad: MessiPaoloni-1
ad: Left-2
ad: Left-3
  1. N8FVJ

    N8FVJ Ham Member QRZ Page

    How do you use a FT-991A antenna tuner into an amplifier tuned input? You cannot tune the radio with the Yaesu in transmit, only in receive with amp off line. Barefoot my antenna is 2.5 to 1 SWR so I tune to that. However, best I can perform for the amp is to tune the Yaesu FT-991A into a dummy load, then connect the Yaesu to the amplifier.
  2. W9WQA

    W9WQA Ham Member QRZ Page

    i think you need to re,explain this, 75 looks,no comments cept mine...
  3. K7MH

    K7MH Ham Member QRZ Page

    Your FT-991A tuner does you no good at all if the amplifier is in use and amplifying. If the amp is off or in bypass you can then use the rig's tuner.
    If you need a tuner when you are running the amp, you need to get an external tuner (either a manual tuner or an automatic tuner) that is rated for the amplifier output and it goes AFTER the amplifier.
    You would have the FT-991A tuner OFF when using the amplifier.

    I have an IC-7600 here and an AL-80B. I use an Ameritron ATR-30 manual tuner after the amplifier.

    Yes...It will cost you more money! Somewhere around $500 or more.:(
  4. K7TRF

    K7TRF Premium Subscriber QRZ Page

    When using the active amp you should disable your rig's tuner. That assumes you've got a reasonably modern amp (really the past 50 years or so) that has tuned input circuits. If you don't see a good match at your rig without using the rig's tuner when it's connected to the operating amp then your amp's input tuning networks may need some adjustment.

    As posted above when the amp is turned off or in standby mode you could use your rig's antenna tuner to match the antenna but with the amp active your rig should see a good match with the tuner disabled.

    The amp may or may not need a high power tuner between it and the antenna system. If it's a tube amp with a PI output matching network the amp should have no trouble loading into a 2.5:1 SWR. If it's a solid state amp you'd want to run an antenna tuner rated for at least the amp's output power (high power tuners tend to have wider usable impedance matching ranges) between the amp and the antenna.
    KU3X likes this.
  5. N8FVJ

    N8FVJ Ham Member QRZ Page

    I look at manual to bypass antenna tuner.
  6. K8JD

    K8JD Ham Member QRZ Page

    If you need help e-mail me. My son used to live right up Lochhaven from your QTH,
  7. N8FVJ

    N8FVJ Ham Member QRZ Page

    Oh, just briefly push switch once and tuner is off line.
  8. W9WQA

    W9WQA Ham Member QRZ Page

    using my internal tuner into anything, amp or other ext tuner always improves the radio match.

Share This Page