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833A




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From:  Stephen G. Stanton [SMTP:ulflyer-at-i-cafe-dot-net]
Sent:  Saturday, February 28, 1998 11:18 AM
To:  'Tesla List'
Subject:  Re: 833A

Does anybody out there have an extra 833A filament clamp (they don't really
use a socket due to the two heater pins at the base) they could part with? 
I find they're getting hard to find at swapmeets.

Thanks again,

Steve, KJ6LH


> From:  SBJohnston-at-aol-dot-com [SMTP:SBJohnston-at-aol-dot-com]
> Sent:  Thursday, February 26, 1998 1:21 PM
> To:  tesla-at-pupman-dot-com
> Subject:  Re:  833A
> 
> 
> Greg wrote:
> 
> >I lucked up on an 833A triode (for free!).  
> >I have no experience with the big tube.  
> 
> By some standards, it is not a "big" tube <grin>:  it's typically a 500
watt
> tube in continuous (CCS) broadcast audio or RF service.   I have always
liked
> them and even built a custom transmitter around four of them.   They
normally
> run a nice orange-red color at full power.    
> 
> The original RCA 833 was a strong tube with a very heavy plate structure.
>  The story goes that they just ran and ran and wouldn't fail, so of
course
> RCA had to redesign a replacement for them, the 833A, with a
lighter-weight
> sheet metal plate that had a shorter life - repeat sales, you know!  I
hear
> that one of the Chinese tube companies is making the 833 to the original
> specs.
> 
> I looked in the RCA transmitting tube book and here are some  detailed
specs
> for your application: 
> 
> Filament:  10 volts ac or dc, 10 amps.
> Plate dissipation w/natural cooling:   350 watts
> Plate dissipation w/forced  cooling:  450 watts
> 
> Class C amp or oscillator RF service, intermittant-duty (ICAS), w/forced
air
> cooling:
> 
> DC Plate voltage:  4000 vdc max.
> DC Plate current:  500 ma max.
> DC grid voltage:  -500 vdc max.
> DC grid current:  100 ma max.
> Plate input:  2000 watts max.
> Plate dissipation:  450 watts max.
> 
> >Is it OK to mount it horizontally?  
> 
> Yes - it says so in the book, but I have not seen them mounted that way
in
> any commercial application.  And I just noticed a week ago that the ones
I
> had in the garage have suffered filament collapse from vibration while
> sitting on their sides <damn!>.   I think would mount it vertically.
> 
> If you'd like I can scan the RCA book pages for you and send it to you
> directly as an email attachment - let me know the graphic format you
prefer:
>  TIFF or GIF (or something else).  
> 
> Steve Johnston
> 
> sbjohnston-at-aol-dot-com
> 
>