How I Tune Up My Amplifier

Discussion in 'Amateur Radio News' started by KM9G, Jul 7, 2021.

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  1. VK7HH

    VK7HH Ham Member QRZ Page

    All knobs to the right TO!
     
    KT5OT, WA8MEA, W9FL and 3 others like this.
  2. M1WML

    M1WML Ham Member QRZ Page

    life,s to short for qrp... :D
     
    W0ARM, KJ7MX, N3FAA and 1 other person like this.
  3. N4CAX

    N4CAX Ham Member QRZ Page

    No, Just no.
     
    M1WML likes this.
  4. AB0R

    AB0R XML Subscriber QRZ Page

    VA3QY, M1WML, DL6SEZ and 1 other person like this.
  5. WA1UIL

    WA1UIL Ham Member QRZ Page

    Yeah, I always spike the plate and tune for the bump so Bird Watts are at the max. "If the lights ain't dim'n..... you ain't pinn'n" Soon exams will be a matter of copy & paste and be sure to grab your participation trophy when exiting the Mc Donalds Playscape VE session.
     
    Last edited: Jul 7, 2021
    KQ1V and M1WML like this.
  6. DL6SEZ

    DL6SEZ Ham Member QRZ Page

    Hi Hams,

    Tom's (W8JI) webpage should everybody with a tube amp read, that's all for right tuning and tube long life!
    Nobody really needs these most time bad made Youtube videos...
    There are so many artificially lengthened up to get quotes never coming to the real points which count, it's a shame.

    73 de Chris DL6SEZ
     
    W0ARM, W2JKT, WN1MB and 9 others like this.
  7. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    When a linear amp is fully loaded, a plate current dip can be very difficult to see. However, tuning the PLATE for a grid current "peak" (not a dip) results in resonating the plate tank exactly as well and is usually easier to see. And adjusting loading while watching output power and grid current allows one to set it properly.

    Tuning an amp with fragile grids, or tuning a tetrode or pentode amp for "max output" by adjusting the loading and watching only that can result in really short tube life.
     
    KD8DWO, K8XG and M1WML like this.
  8. KM9G

    KM9G Premium Subscriber QRZ Page

    This is a really good tip! I think I'm going to have to ruminate and practice a bit to fully grok it. One of the harder parts, so far, for me is that the amp has different efficiency on different bands - and this one seems to change its mind depending on the weather (I'm guessing ambient temperature issue)... so I don't know what "full power" input is yet as the target keeps moving. You're a level or 3 ahead of me here, thanks for the help!
     
    M1WML likes this.
  9. KG0J

    KG0J Premium Subscriber QRZ Page

    I second the recommendation to watch W8JI's videos and consider getting his TOF tuning aid. It protects the amplifier from overcurrent on the grid and makes tuning MUCH easier and faster and shows you true grid current. I'm running the TOF on my 811H, literally just takes a few seconds to safely tune to maximum power.
     
    KR3DX, KT5OT, KM9G and 1 other person like this.
  10. NX4RH

    NX4RH XML Subscriber QRZ Page

    KD8DWO, KM9G, M1WML and 1 other person like this.

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