Virtual Valve Museum

CV2482 ATR cell

This cell measures 145x12mm overall.

Note A: The tube is intended to be inserted across a suitable waveguide mount at any frequency in this range. The bandwidth and matching are determined by the mount design.

Note B: For a single tube operating across both waveguides of a balanced duplexer.

Note C: Minimum breakdown power depends upon mount design. When the tube is mounted across WG16 breakdown occurs at peak incident power levels above 10kW, the ionisation time being about 0.02µs. At S-band, mounted across a resonant iris having a loaded Q of 2, breakdown occurs at less than 2kW incident power, when a short circuit is placed a quarter wavelength behind the tube.

Note D: The hole through which the tube is mounted should be 0.3576 inches +/- 0.0005 diameter.

Note E: In all high power applications adequate choking is required where the tube passes through the waveguide walls and the tube should be in contact with the transmitter side of the mount.

Typical operation

Primary switch at 9 to 10 GHz balanced duplexer

A single tube mounted across WG16 gives a VSWR of less than 1.1 over a band in excess of 1GHz with an insertion loss of less than 0.1dB. For a line power of 250kW peak, leakage to the receiver is about 200 ergs spike and 200W peak flat. Life is in excess of 3000 hours and recovery time less than 8µs.

Primary switch in WG11 phase shift duplexer

Two tubes may be used across an iris structure to form the phase shifting element of the duplexer. A bandwidth of 10% to a VSWR of 1.1 can be obtained for an insertion loss of less than 0.2dB. With a line power of 1MW the arc loss is about 0.15dB and recovery time less than 20µs. The leakage power is about 5kW peak depending upon the directivity of the first hybrid.

Primary switch in WG16 phase shift duplexer

A single tube may be used across WG16 to form the phase shifting element of the duplexer. For a line power of 800kW peak, 600W mean, arc loss is about 0.1dB and leakage power to the receiver about 3kW peak. The short circuit position is between 0.100 and 0.130 inches forward of the tube axis. Life is in excess of 3000 hours for operating pulse widths of 1µs and less.