2m DISCOVERY LINEAR AMPLIFIER (GS – 31) Operating Manual WiMo Antennen und Elektronik GmbH Am Gäxwald 14, D-76863 Herxheim Tel. (07276) 96680 FAX 6978 http://www.wimo.com e-mail: info@wimo.
INDEX 1. 2. 3. 4. 5. Specifications Introduction Installation Operating Controls Operation CAUTION There are dangerously high voltages inside the amplifier when the power is switched on. DO NOT remove the covers unless the power has been disconnected and sufficient time has elapsed for the capacitors to discharge. NOTE The 2m Discovery is capable of a greater power than the CW rating shown in the specifications.
(1) 1. SPECIFICATIONS Function………………….The 2m Discovery is a desk top linear RF amplifier with a nominal output of 1000W covering the range 144-146MHz for amateur radio use. Type of emission…………………………………………………SSB/FM/CW/RTTY Dimensions………………………………….……14in wide x 9.75in high x 17in deep 360mm x 250mm x 430mm Weight……………………………………………………………………………..25kg Output power…………………………………...…………………….1000W CW/SSB Gain……………………………………………...………………………12dB nominal Power requirements………………………………..
(2) 2. INTRODUCTION The 2m Discovery is a high quality linear amplifier which is designed around a GS 31 medium mu triode in grounded grid configuration. The amplifier uses a ¼ wave stripline in the output circuit and a tuned input circuit. 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 GS 31 must be allowed to warm up properly hence a 2 min. start up timer is fitted.
(3) 3. INSTALLATION SETTING UP a) Unpack the amplifier and check that it is undamaged. The carton should also contain a power cable, operating manual, phono plug (for relay switching lead) and spare fuse. Please retain the packing and box should it be necessary to ship it or move it to another location. b) Ensure you have a reasonable airflow around the site you have chosen to install your amplifier. Do not enclose the cabinet or restrict the airflow in any way.
(4) 4. OPERATING CONTROLS FRONT PANEL CONTROLS ON/OFF SWITCH…………………………………………....Mains power on and off STBY/TX……………………………………….…………Amplifier standby / operate PLATE METER……………………..0 – 1.5A, monitors the plate current of the valve GRID METER…………………………...0 – 400mA, monitors the grid current which should not rise above 300mA GRID / RF OUT…………………..switches the grid meter to monitor relative RF O/P (LOAD CONTROL……………………………..
(5) REAR PANEL FUSE HOLDER…………………………………………………1.25” (30mm) 10A MAINS……………………………………..IEC connector for mains cable, 230VAC TX………………………N – type connector, coaxial INPUT to amplifier from driver ANT…………………….N – type connector, coaxial OUTPUT to antenna through a suitable power meter PTT…………………………………….……Phono connector for relay switching lead WiMo Antennen und Elektronik GmbH Am Gäxwald 14, D-76863 Herxheim Tel. (07276) 96680 FAX 6978 http://www.wimo.com e-mail: info@wimo.
(6) 5. OPERATION SET-UP Connect all the cables as previously described in the manual, then double-check. When you are satisfied that everything is correct and the STBY/TX switch is on STBY, switch the amplifier on. There is a slight delay while the soft-start operates, then the POWER and WAIT lights should be on. After approximately 2 minutes the WAIT light should go out, indicating that the valve has warmed up and is ready for operation. Now put the STBY switch to TX, which puts it into the operate mode.
(7) To reset the amplifier, put the STBY/TX switch to STBY then back to TX. The LED should now have gone out and the amplifier is able to be keyed once more. Tune the amplifier correctly to achieve maximum output with minimum grid current. WiMo Antennen und Elektronik GmbH Am Gäxwald 14, D-76863 Herxheim Tel. (07276) 96680 FAX 6978 http://www.wimo.com e-mail: info@wimo.
(8) OPERATING PRECAUTIONS To ensure safe and reliable operation please regard the following precautions:HIGH VOLTAGES CAN BE LETHAL. Never try to operate your amplifier with the covers removed. If it is necessary to work inside the cabinet, always disconnect the Mains supply and allow the capacitors to discharge fully. Never operate the amplifier into a load or antenna with an SWR greater than 2 : 1. Always tune the amplifier for resonance using low drive at the operating frequency.
(9) WARRANTY Linear Amp UK Ltd warrants to the original purchaser that this product shall be free from defects in material or workmanship for 12 months from the date of the original purchase. Valves are excluded from this warranty. Notification should be given as soon as possible after discovering a possible defect. Carriage charges for any parts or units submitted for replacement or repair under this warranty must be paid by the purchaser.
