Power and Protection for your Tetrode PA

THE TETRODE BOARDS are based on G3SEK's article 'Power and Protection for Modern Tetrodes' in QEX for October 1997.

The set of two PC boards does everything mentioned in that article, and more:

'Universal' power and control unit for almost any tetrode PA. * Carefully designed to protect your tetrodes, and help them deliver a high-quality signal. * Suitable for either one or two tubes, including 4CX250, 4CX350, 8930, 4CX400, 4CX600, 4CX800, 4CX1000, 4CX1500, 4CX1600A (or 4CX1600U/GS23B, YL1050/2/6 etc. with minor modifications).
Versatile - use with grounded cathode, screen or control grid.
Regulated and adjustable screen grid supply: 350-400V, +/-50mA source/sink (adaptable for other voltages and currents).
Regulated and adjustable control grid supply (5V adjustment range, other voltages by changing zener diode). * Screen-grid currents monitored for sensitive fault detection. No risky grid fuses!
Grid-current derived ALC and overdrive protection.
Controls your High Voltage supply too - any fault condition disables PTT and HV for safety. Just press the RESET button to continue.
Built-in 12/24V DC relay supplies.
Sequenced relay switching with transceiver RF drive inhibit.
Metered screen and grid currents.
Two compact PC boards (both 5in x 4in, can be stacked).
All power rectifiers and smoothing capacitors on-board. * Optional mains transformer (for screen voltage 300-400V).
CONFIGURABLE FOR YOUR SPECIAL REQUIREMENTS.
DETAILED 'HOW-TO' INSTRUCTIONS.

THE TETRODE BOARDS are available either on their own with the full Instruction Manual, or as a complete kit with on-line support from the designer.

73 from Ian G3SEK Editor, 'The VHF/UHF DX Book' 'In Practice' columnist for RadCom (RSGB)