tacles for 200-240V circuits. ALWAYS use grounding type AC connectors which conform to
local codes and ensure that the green/yellow wire in the 91 fi power cable is wired only to
the AC mains safety ground (or to neutral, as may be necessary with a 240V circuit config
ured 120V-N-120V without a separate ground, commonly found in the US).
The green/yellow conductor in the power cord is wired to the ETO 91/3 chassis. It MUST be
connected only to the power source safety ground or neutral. The blue and brown power
cord wires connect to the two "hot" wires of the AC source; either wire may be connected to
either side of the line. For best results use a dedicated 200-240V branch circuit of #10 AWG
copper wire or equivalent, rated at 20A, to feed the amplifier.
Important information concerning operation from 90-130V mains
Electrical power equipment will draw twice as much primary current from 120V mains as
from 240V mains. Therefore, operating the ETO 91/3 on a typical 120V¡20A household circuit
without exceeding the 20A circuit rating will limit maximum peak power output to about 600-1000
watts. Maximum possible RF output power for any particular primary AC voltage and cur
rent capacity may be estimated as
Po max = (Vline x Dine) / 2.3.
For example, if the 91(3 operates from a circuit which is capable of delivering 115VAC at a
maximum current of 20A, with no other loads connected to the circuit maximum peak RF
output possible without tripping the 20A breaker (or fuse) is approximately
Po max = (115V x 20A) / 2.3 = 2300/2.3 = 1000 watts.
If the same circuit also supplies a transceiver drawing peak line current of 5A and a lamp
drawing 1 A, only 20-5-1 = 14A is available for the amplifier and maximum possible output is
about
Po max = (115V x 14A) / 2.3 = 1610/2.3 = 700W.
RF Grounding
A ground stud with wing nut is provided on the rear of the chassis. Connection should be
made from this stud to a good RF earth ground, such as a copper water pipe or driven rod,
via heavy copper braid or strap. CAUTION: When using any high power amplifier, failure to
connect ALL station equipment to a good common ground may allow RF feedback to leak into the
transceiver and cause severe signal distortion.
Replacing the Amplifier Cover
Use only the 6-32 screws supplied with the amplifier and do not tighten any of the screws
until all are started.
5
To Next Page
Loading...
