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Russian G-811 Tube - Excellent

Discussion in 'Amateur Radio Equipment Reviews' started by N8FVJ, Jun 22, 2019.

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  1. N8FVJ

    N8FVJ Ham Member QRZ Page

    Old tubes such as the stellar RCA 811A are about extinct. The Chinese 811A do not last long and some report the output falls off after 2 years use. Some fail new out of the box. The old RCA would last 20 years or longer, so what is a solution to low 811A tube life?

    The Russian 811 called a G-811 is a superior 811A that will also last 20+ years like the RCA 811A. The difference is likely the RCA 811 having a thoriated filament. Thoria is a natural occurring radio active material that maintains the electron cloud in a tube tungsten filament under a vacuum. The process also requires carbonization of the filament to control thoria loss. The process takes more time to build a tube and thoria is not exactly easy to source and use. Thoria is a non-regulated radio active element. The Chinese are cheap and will produce a inferior tube. In other words, toss you under the bus for a dollar.

    The Russian G-811 is properly manufactured like the old RCA 811A. The G-811 are sold on ebay for about $17 each or less cost vs the Chinese 811A.
     
    W1TRY likes this.
  2. KA9JLM

    KA9JLM Ham Member QRZ Page

    Is that the price for new ?

    Do you have a Web link ?
     
  3. N8FVJ

    N8FVJ Ham Member QRZ Page

  4. KU3X

    KU3X Ham Member QRZ Page

    Not all tubes are equal ! Can the Russian version of the 811 be laid on their side?
    That is a big problem with some of the 811 tubes. The Collins 30 L1 tubes are on their side so care must be taken in choosing the proper tube.
    The old Eimac book would spell out what position any of their tubes can be mounted.

    Barry, KU3X
     
  5. N8FVJ

    N8FVJ Ham Member QRZ Page

    I would not trust Russian G-811 on their sides with regard to filament sag. Use G-811 in the Ameritron AL811/AL-811H amps.
     
    KU3X likes this.
  6. N8FVJ

    N8FVJ Ham Member QRZ Page

    BTW- I read a ham has had the G-811 in his amplifier for 20 years and the Chinese 811A were reported to last only 1500 hours per another ham.
     
  7. N2EY

    N2EY Premium Subscriber QRZ Page

    I don't think Eimac ever made 811As.

    The RCA HB-3 sheets say the 811A can be mounted horizontally IF pins 1 and 4 are in the vertical plane. (See attached).
     

    Attached Files:

    • 811A.pdf
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    WA7PRC likes this.
  8. KU3X

    KU3X Ham Member QRZ Page

    You are correct, they did not.
    Just making a point.

    Barry
     
    N2EY likes this.
  9. N8FVJ

    N8FVJ Ham Member QRZ Page

    I recently read the G-811 is properly oriented to the socket pins and can be mounted horizontally. But, I am still a little wary.
     
    KU3X likes this.
  10. N8FVJ

    N8FVJ Ham Member QRZ Page

    BTW- The Russian G-811 is same internals as the Svetlana 811A built by same Russian factory.
     

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