DRAKE L7 Betreibershandbuch PDF herunterladen (Seite 30)

with the standard wattmeter or with the RF

power calculated from the RF voltage mea-

sured across the 50 Ohm load.

5-16.

3000

WATTS FORWARD

a. After the 300 watts forward calibration, set the

bandswitch to 20 meters and tune it up as

described in Chapter

"Operation." Place the

meter switch in the FWD 300 position adjust

the exciter for

1000 watts output from the

amplifier.

b. Adjust

R26 so that the

wattmeter agrees

with the standard wattmeter or with the RF

power calculated from the

voltage measured

across the 50 ohm load.

5-17. KNOB POINTER ALIGNMENT

When replacing the knobs on the L

amplifier,

correct alignment of the PLATE and LOAD con-

trols is important. All of the other controls have

flats on the control shafts and the setscrewsin the

knobs should press against the flats. The

PLAT%

and LOAD control shafts should be rotated so that

the plates of the variable capacitor are fully

meshed, and the pointer should be resting in a

nine o'clock position at the end of the tuning arc.

5-18. POWER SUPPLY ClRCUli

BREAKER RESET

There are twabuttons on the power supply which

are provided for resetting the circuit breakers in

case they should trip from overloading. If the

circuit breakers trip, turn off the amplifier and

wait for one minute before resetting. If the circuit

breakers trip immediately after resetting and

turning the amplifier on, an investigation should

be made to determine the cause of the overload.

5-19. REMOVING THE BOTTOM

COVER

WARNING

SURE that the

Power Supply is un-

plugged from its power source.

. .

After completely disconnecting all sources of

power, the bottom cover of the Power Supply can

be removed by taking out all of the screws around

the bottom of the chassis.

5-20. REMOVING TOP COVER

WARNING

SURE that the

Power Supply is un-

plugged from its power source.

The top cover cannot be removed until the bottom

cover has been removed. After the bottom has

been removed, remove the line cord wires from the

barrier strip and ground. The top can then be re

moved by taking out the remaining screws

holding the

top

cover to the chassis.

5-21. POWER SUPPLY TROUBLE-

SHOOTING

Careful consideration has been given to the design

of the

Power Supply to keep maintenance

problems to a minimum. However, if the Power

Supply fails to function, first check the circuit

breakers and reset them if it is necessary. If the

circuit breakers continue to trip, check for short

circuits in the high voltage line. Especially be

certain that the high voltage interlock in the

Amplifier

not shorting the high voltage to

ground as

is supposed to do when the top cover

is taken off the amplifier. If the circuit breakers

have been tripped because of a short in the high

voltage line, a continuity check should be given

to each silicon diode bank in the Power Supply to

determine if either or both banks have failed. In

the event of a short circuit, resistor

R12 in the

Power Supply will be destroyed. This resistor pro-

tects the diodes in the Power Supply and it should

be replaced with an IRC 0.82 Ohm

Watt type

BWH

resistor ONLY.

the event of a difficulty

we recommend that you return your unit to your

dealer, or write directly to our Customer Service

Department describing your problem in detail.

Include full information concerning the circum-

stances during the failure, any measurements

that were made and be-sure to include the serial

number.

1 2 ... 25 26 27 28 29 30 31 32 33 34 35 36 37

Kommentare zu diesen Handbüchern

Keine Kommentare

DRAKE L7 Betreibershandbuch Seite 30

Kommentare zu diesen Handbüchern