Specifications

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2. INTRODUCTION
The 70cm Discovery is a high quality linear amplifier, which is designed around a
GS 31 medium mu triode in grounded grid configuration. The amplifier is forced air
cooled to give you the ability to operate at full output power for as long as you wish.
The recommended maximum drive is 100Watts.
The new model of the Discovery features a specially designed Triode control board
by G3SEK. This control board incorporates all the following protection features:-
Grid over-current, Plate over-current, Internal valve flashover and Overdrive. It also
has sequenced relays and high speed switching relay.
The GS 31 must be allowed to warm up properly hence a 3 min. start up timer is
fitted. When the amplifier is switched on, the yellow WAIT/GRID LED comes on.
After 3 min has elapsed the WAIT light will go out and the green READY LED will
come on allowing you to operate the PTT.
It is recommended that you use a Bird (or equivalent) power meter capable of
measuring 1500W at the correct frequency.
Please read the instructions carefully before operating the equipment. RF amplifiers
at this power level and frequency can be easily damaged by improper use. Please
follow the precautions on page 1 of this manual.
The Discovery is fully self-contained and has three separate voltages:-
1. HIGH VOLTAGE which is 2800V, the main voltage applied to the valve
anode.
2. HEATER SUPPLY which is 13V at 3A.
3. CONTROL VOLTAGE which is 20V used for the LED control condition of
the amplifier, also for pulling in the Tx/Rx relays.