Ehrhorn Technological Operations ALPHA 76A, Руководство по эксплуатации и техническому обслуживанию, Страница: 4 / 19

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4. Physical Location: Your ALPHA must be located so that intake of cool a i r
through the rear panel, and exhaust of warm a i r through the top cover per­
fo ra tio n s, i s not impeded in any way. A minimum of 4 to 6 inches of c le a r­
ance should be allowed behind and above the am plifier for a i r c irc u la tio n .
BE CAREFUL NOT TO BLOCK THE TOP-COVER EXHAUST OPENINGS with log books or
equipment.
5. RF and Control Connections: Interconnection o f the ALPHA for operation with
any popular transceiver or exciter i s extremely simple. Connect the rear
panel jacks as follows:
RF INPUT - Use an appropriate plug and RG-58C/U or sim ila r small 50 ohm
coaxial cable to connect to transceiver or exciter " r f output" or "antenna"
connector.
KEEP CABLE AS SHORT AS POSSIBLE - - PREFERABLY NOT LONGER THAN
2-1/2 TO 3 FEET.
RF OUTPUT - Use a standard PL-259 ("UHF" type) plug and RG-8A/U or sim ila r
high power coaxial cable (50 ohm) to connect to antenna system.
RELAY - Use a standard "phono-type" patch cable to connect t h is jack to
transceiver or exciter contacts which are "open" on receive and "shorted"
on transmit ("N.O." = "normally open").
Nearly a ll transceivers provide
such contacts via either phono-type jacks or other accessory connector on
the rear panel or the power supply.
NOTE: When the am plifier i s OFF, or in the RECEIVE condition with no^ short
across i t s RELAY lin e , the RF OUTPUT connector i s in t e rn a lly connected d i ­
re c tly to the RF INPUT, providing normal "transceive-type" antenna input to
the receiver.
ALC - For use with tube-type transceivers having negative-going ALC systems
with external input jacks, simply patch t h is jack to the mating one on the
transceiver or exciter, using a standard "phono-type" cable.
Nearly a ll
modern s o lid state (broadband) transceivers u t i l i z e p ositive -goin g internal
ALC, with a detector at the r f output point. This internal system normally
functions adequately to control SSB drive power to the am plifier; in fact,
most such exciter/transceivers provide no external ALC input jack and i t i s
e n t ir e ly unnecessary to make any external ALC connection.
6. Blower: The cooling blower motor is mounted on a new "absorbent foam" cushion
which dramatically reduces transmission of mechanical noise and vibration.
Two 10-32 P h i l l i p s head screws secure the blower motor to the amplifier rear
panel for safety during shipment, and must be removed for quietest operation.
These two screws are id e n tifie d with arrows in FIGURE 2 on page 11 o f th is
manual. Remove both screws f u l l y , and the rubber s t r i p s wedged between the
rear panel and the blower motor bearing housing (between and s l i g h t l y above
the screws); save for future shipping.
SERIOUS PHYSICAL DAMAGE TO THE AMPLI­
FIER AND BLOWER MAY RESULT IF THE SCREWS AND SHIM STRIPS ARE NOT PROPERLY
RE-INSTALLED BEFORE SHIPPING THE AMPLIFIER!