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833A
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From: vonpostel [SMTP:vonpostel-at-prodigy-dot-net]
Sent: Wednesday, February 25, 1998 4:50 AM
To: Tesla List
Subject: Re: 833A
Tesla List wrote:
>
> ----------
> From: Gregory R. Hunter [SMTP:ghunter-at-mail.enterprise-dot-net]
> Sent: Tuesday, February 24, 1998 12:14 PM
> To: Tesla List
> Subject: 833A
>
> Hi Guys,
>
> I lucked up on an 833A triode (for free!). I have no experience
> with the big tube. Is it OK to mount it horizontally? I plan to
> run mine pretty hot using a 1KVA MOT for +B.
> yielded a nice, open-frame 5" blower--suitable for cooling the tube?
> Any advice on care & feeding of the 833A would be much appreciated.
>
> Greg
>
> East Anglia, UK
Greg:
General Electric Transmitting Tube manual, in talking about forced-air
cooling, says: "....an air flow of 40 cfm froma two-inch diameter nozzle
directed verticaly downward on bulb between grid and plate seals is
required." (When running in maximum ICAS condition. "Operating
position....vertical, filament terminals up or down horizontal with
plate in a plane vertical."
Typical ICAS operating conditions, class C oscillator, with forced air
cooling:
Filament: 10 volts 10 amps
D.C. plate voltage: 4000
D.C. grid voltage: - 225 volts obtained frm a fixed supply or 2400
ohm grid resistor or 380 ohm cathode resistor
D.C. plate current: 500 MA
D.C. grid current (approx.) : 95 MA This will vary with the load
impedance.
Peak r.f. grid input voltage (approx.): 415 v. peak
Driving power: 35 watts.
Plate power output: 1600 watts.
The connections to the plate and grid should be made with finned heat
radiating connectors if you intend to push the tube. They don't like to
have hot seals. Be generous with the amount of metal in the filament
connectors. ( I assume that a socket and connectors didn't come with
the tube.) Watch the color of the plate. My experience has been that
833-As don't give good service if you try to run them more than a
very dark cherry red. By good service I mean 7 days a week, 24 hrs per
day. The typical operation above is for intermittant commercial amateur
service.
Hope this helps.
Ray