Installation And Application

The base pins of the 834 fit the standard four-contact socket, such as the RCA type UR-542A. The socket should be installed to hold the tube in a vertical position. The filament terminals are connected to the two large base pins; the grid and plate leads are brought out through separate seals at the top of the bulb. See outline drawing.

Connections to the grid and plate leads must be flexible enough so that normal expansion will not place a strain on the glass at the seals, yet heavy enough to carry the high circulating r-f current. It is also necessary to provide a means for cooling the lead tips and their seals. A recommended method of doing this is to increase the radiating surface of each lead by means of a copper clamp connector having a cross-sectional area of at least % inch square. (See next page for constructional details.) Each lead wire should be connected to its copper clamp before the clamp is placed on the terminal tip. The clamp should be slightly sprung so that it can easily be slipped over its terminal. When the clamp is in place, carefully tighten the smaller bolt to insure good electrical contact. Connections should never be soldered directly to the tube terminal tips as the heat of the soldering operation may result in the cracking of the lead seals. The tube terminal tips should not be used to support coils, condensers, chokes, or other circuit parts.

The bulb becomes very hot during continuous operation. Therefore free circulation of air about the bulb should be provided. When the 834 is operated at frequencies higher than 60 megacycles, forced cooling of the tube is recommended. This may be done by means of a small electric fan. Under any condition of operation the maximum bulb temperature should not exceed 175°C (347°F) as measured by a thermometer placed against the glass at the top of the tube, midway between the grid and plate leads.

The plate of the 834 shows only a barely perceptible red color at the maximum plate-dissipation rating for each class of service.

For high-frequency operation above 100 megacycles, see page 144.

For additional information, see chapters on INSTALLATION and APPLICATION.

average plate characteristics

radiating connector

CO «-32 X \ RD. HD. BRASS SCREW t NUT * 541055") DRILL (i) 0-32 .BRASS WASHER

Was this article helpful?

0 0

Post a comment