Tuned input for a 4 - 1000 a grounded grid amplifier

Discussion in 'Ham Made Gear' started by NY5E, Jan 2, 2019.

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  1. NY5E

    NY5E Ham Member QRZ Page

    Good morning everyone, I have a 4 - 1000a grounded grid amplifier in good shape but, I haven't operated it in at least a dozen years. So now I'm getting it prepped to get some heat in my shack and have that nice fire glow orange light being cast out and onto the walls along with that nice ionized odor in the air. I'm interested in putting a tuned input circuit into rf deck.
    And it has the common problem of high swr's between the Exciter and the amplifier
    The problem is I've looked everywhere for maybe a ready-made one to match that tube or a kit or something. I found wd7s on the web that did offer a kit but, I spoke with his wife and actually he's no longer in business due to his passing last year.
    So my question is does anyone know of a kit a board or a place I can get all the parts to build up myself.
    I run 80 thru 10 meters and can put up to 6.5kv on the plate. I can either drive it with a TS 830s or an ft1000 Mark V 200 watt.
    Also may be interested in putting 160 m on this same amplifier.
    Thank you, 73 de KB5LIP
    Ron Woods

    Attached Files:

  2. AD5HR

    AD5HR Ham Member QRZ Page

    Maybe run a small "tuner" between the exciter and amp input?
    I would use the ft1000 as the exciter, in GG, that tube likes 120
    to 130W drive.
  3. NY5E

    NY5E Ham Member QRZ Page

    Thanks for your reply Jon I have an auto tuner in the Yaesu Mark V I also have a small Heathkit antenna tuner that I built years ago I could put between the 830 exciter and the amplifier but I want to do it I guess I'll call it the correct way maybe just the better way with the independent band input tuning. Perhaps a cleaner output signal the tube would like that a lot better I'm sure and also I hear gives you a few extra hundred Watts so it would be easier the equipment all the way around. Ron
    AD5HR likes this.
  4. KL7AJ

    KL7AJ Ham Member QRZ Page

    HI Ron. At HIPAS Observatory (the predecessor to HAARP), our eight 150 KW transmitters used 4-1000As for the drivers. We used a small fixed-tuned tuner (300 watt, homebrew) for the input stage of each of these, (using Henry solid state drivers). These tuners were very simple, a parallel LC circuit with a small tap on the inductor, providing a perfect match....at one frequency. If you twiddle the L/C ratio, you should be able to broaden the tuning enough to cover any HF band....except for maybe 80 meters.
  5. KU3X

    KU3X Ham Member QRZ Page

    Confirm your email address is ok on your QRZ page and I will send you your needed 4-1000 amp information.
    Last edited: Jan 3, 2019
  6. NY5E

    NY5E Ham Member QRZ Page

    I went in and updated my email .
    Thanks for your reply. I'll be looking for the info.
    Kb5lip@gmail.com รท
  7. W8DL

    W8DL Ham Member QRZ Page


    I have what may be exactly what you are looking for that I put together for a single 4-1000
    back in the 1990s... It is a tuned input for a 4-1000 with ~6000V on anode. The circuit
    is built in a separate aluminum box for isolation and covers 80,40,20,15, & 10 meters. It has an independent
    band switch and knob on the box. Also each band can be tweaked with external tunable inductor screws (if
    desired) but chances are very unlikely that you would need/want them, unless you are needing to cover
    a range outside the ham bands. I would be willing to let this go for a reasonable price if it meets your needs.
    I can provide pictures, as well as dimensions if you are interested.

    Let me know, and in any case good luck to you in finding a solution..

    Don - W8DL
  8. NY5E

    NY5E Ham Member QRZ Page

    Hello Don and thanks for the reply sure I may be interested in something like that feel like I would like to send some pictures and further discussion my email is kb5lip at@gmail.com
  9. NY5E

    NY5E Ham Member QRZ Page

  10. NY5E

    NY5E Ham Member QRZ Page

    Are you still interested in doing business on the input circuit box?

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