GENERAL DESCRIPTION |
![]() |
The TH 561 is a ceramic-metal tetrode of coaxial structure employing Hypervapotron anode cooling. It can be used as a CW oscillator, AF or RF power amplifier operating up to 300 MHz. Fitted with an integral water jacket, the Hypervapotron-cooled anode of the TH 561 can dissipate 20 kW, with a comfortable safety margin. |
![]() |
TECHNICAL SPECIFICATIONS | |
ELECTRICAL | |
Type of cathode | Thoriated tungsten |
Heating | Direct |
Filament voltage | 7.0 V ± 2% |
Filament current | 140 A |
Maximum surge current | 450 A |
Interelectrode capacitances : - cathode - control grid (g1) - cathode - screen grid (g2) - cathode - anode - g1 - g2 - g1 - anode - g2 - anode |
83 pF 5.3 pF 0.12 pF 135 pF 0.8 pF 17 pF |
Amplification factor, g1 - g2 | 5.5 |
Transconductance (Ia = 2 A) | 60 mA/V |
MECHANICAL | |
Operating position | Vertical |
Anode cooling |
By circulating distilled water at high temperature |
Maximum anode dissipation | 20 kW |
Minimum water flow | 12 l/mn |
Maximum temperature of inlet water | 50 °C |
Maximum temperature of outlet water | 90 °C |
Maximum pressure allowed at the water-jacket input | 4 bar |
Maximum temperature at any point of the ceramics | 250 °C |
Weight, approx. | 4.4 kg |
Specifications may change without notice |
THIS TUBE IS USED IN THE FOLLOWING SHORTWAVE BROADCAST TRANSMITTERS | ||
Manufacturer | Transmitter specifications | Power in kW |
Telefunken | S 4003 | 300 |
S 4005 | 500 | |
S 4105 | 500 |
THIS TUBE IS AVAILABLE FROM | ||
Manufacturer | Rebuilder | Distributor |
Thales | Econco | Richardson Electronics |
Kennetron |
PRICE LEVEL (US$) | |||||
1 | 2 | 3 | 4 | 5 | 6 |
0 - 10 | 10 - 100 | 100 - 1000 | 1000 - 10,000 | 10,000 - 50,000 | 50,000 - 100,000 |