TUBE RS 1072 C


picture RS 1072 C The RS 1072 C is a forced air-cooled, metal-ceramic tetrode for frequencies up to 300 MHz, output power approx. 1 kW.
The tube is particularly suitable for single-sideband and linear amplifiers.

Heater voltage 3.8 V ±5%
Heater current 20.5 ±2 A
Preheating time > 3 min
Type of heating indirect by ac or dc
Cathode matrix oxide
µ-factor of grid 2 ±11
Transconductance ±43 mA/V

min nom max
Cathode/grid 1 32 36 39 pF
Cathode/grid 2 1.2 1.5 1.8 pF

0.015 pF
Grid 1/grid 2 50 57 65 pF
Grid 1/plate

0.15 pF
Grid 2/plate

12 pF
Specifications may change without notice

Tube mounting and connecting

Sufficiently flexible spring-finger contacts must be used to connect the tube. Suitable spring-finger contacts are available as accessories. The reference edge serves simultaneously as stop edge.

If the tube RS 1072 C shall be clamped to the socket to prevent it from jumping out during shock and vibration, the clamping pressure must only effect the stop edges. Mounting position of the tube a required.

Forced air cooling

The heat generated by the plate dissipation is removed by means of a forced air stream.

The cooling must be dimensioned such that the maximum permissible temperature of 250°C/482°F is not exceeded at any point of the tube surface.

The diagram is valid for the maximum permissible surface temperature and for the usual air supply from the electrode contact side. Air supply from the side of the plate is also permissible, but a somewhat higher air flow rate will then be necessary. A cooling air diagram for this type of operation can be obtained on request.

It must be ensured that outlet and inlet air is also used for the cooling of grid and cathode terminals. The specified cooling air diagram is only valid for a pressure drop at the plate radiator. Pressure losses is supply lines and cavities must be additionally considered when chosing the blower.

Safety precautions

In order to avoid premature tube failure on account of possibly occurring transient spark-overs, we recommend a high-speed trip circuit for the plate voltage providing a fast removal of the electrode voltages. By means of a simple test wire method it must be checked whether the chosen high-speed trip circuit meets the requirements for sufficient tube protection. For this purpose the plate voltage applied is short-circuit directly at the tube terminals by means of a 0.12 mm diameter copper wire (length 2 to 3 cm per 1000 V). If the copper wire does not melt, the high-speed trip circuit meets the requirements.

In certain cases an additional protective resistor of appropriate value should be provided in the plate circuit, which will absorb the major part of the capacitor's load energy in case of tube spark-over and thus enables to meet the test wire requirements.

To protect the plate against thermal overload, the use of a tube fuse is recommended which in connection with a pull switch will disconnect the applied voltages in case of overload.

A protective gap shall be provided between screen grid and cathode, protecting the control grid and the cathode against damage in case of spark-over from the side of the plate.

Moreover, a limiting circuitry is recommended for screen grid protection.

Manufacturer Transmitter specifications Power in kW
RIZ Transmitters OR 50 K-01/A 50
OR 100 K-01/A 100

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