Calibration of the AL-811H

Discussion in 'General Technical Questions and Answers' started by K2ICC, Nov 11, 2020.

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  1. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Whoever told you that doesn't know what he's talking about.

    Those resistors are in series with the panel meter, to read voltage. You can remove them altogether and that won't result in "less power," it will just make the meter reading "zero" on the HV scale.
  2. K2ICC

    K2ICC Ham Member QRZ Page

    Thanks for the clarification. It seems to me a lot of the plan has not to be done at all. I understand the approach of some others into refreshing the equipment with new parts. Got the same answers from tech at the manufacturers on the alignment, coils, parts etc. Once I get my hands on it, since I have not done anything to it, will get more familiar with the amp and will keep for a long time. The swap of the 811's for the 572's was another suggestion, but if not necessary, I wont do either. I just want a little bit more of power to nets such as the 80 meters one locally, and some others, but not expecting to use full power of it. Hopefully it will last.

    Thanks for the help.
  3. KQ0J

    KQ0J XML Subscriber QRZ Page

    I swapped my 811's in my 811H with 572B tubes - they actually have a bit more gain than the 811's but I never could get full advertised power from the 811's.

    My main reason for the upgrade is they are so much sturdier. The 811's these days are garbage and the plates will melt easily. If you are just using SSB you will
    be safer - except when tuning up.

    If your parasitic board looks burned then replace it. I had the known problem ( on my 811 3 tube model) with the parasitic board resistor overheating on 10M due to the
    improper coils being used.
  4. K2ICC

    K2ICC Ham Member QRZ Page

  5. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    With the one pictured (frayed cable from one tube to the parasitic suppressor board, one parasitic suppressor having one more turn than the others, etc.) I'd have just used it. Should work fine, assuming the tubes are good.

    None of this stuff is's "HF," below 30 MHz, where not much at all is critical.

    But the tubes have to be good.

    Ameritron sold an awful lot of AL-811s and AL-811Hs and most of the "problems" are cockpit error, by operators who never used an amplifier before.
    WG8Z likes this.
  6. KA9JLM

    KA9JLM Ham Member QRZ Page

    QC was out to lunch.
  7. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    As long as it doesn't short-circuit to anything, I wouldn't care.

    Now, tomorrow evening, Space-X should be out to launch.

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