DRAKE L7 Manual do Operador descarregar pdf (Página 25)

CHAPTER

4-1.

INPUT

Refer to the schematic diagrams figures

5-4

and

5-5.

The

ohm input is matched to the final

amplifier cathodes by a pi-network on each band

which is selected by the input switch

S1.

Theinput

switch is ganged to the plate circuit bandswitch

SIB. Negative feedback

the

Amplifier is

obtained by slightly raising the grids above

ground with capacitors

C19,

C20,

C21,

C24, C25,

and

C27.

4-2.

TRANSMITTING AGC

When the negative-going peak

voltage from

the capacitor divider

C17

and

C18

exceeds the

positive bias set by

R4,

the transmitting

AGC

threshold control,

CR1

conducts and a negative

voltage proportional to the

signal applied to

the input appears at the transmitting

AGC

output

connector.

THEORY OF OPERATION

4-3.

STANDBY CUTOFF BIAS

positive voltage

from

the resistor divider,

R9,

R10 and R11 in the Power Supply is applied to the

cathode during standby which

cuts off the plate

current.

4-4.

OUTPUT

The plate circuit

matched to the

ohm output

by the adjustable pi-network consisting of

L9-L11,

C42, C43

and

C46-C50.

4-5.

WATTMETER

The directional wattmeter basically consists of

L13, C53,

C54

and

C55,

which take the sum and

difference of the transmission line phase voltages

and currents

indicate forward and reflected

power.

CR4,

CR5,

C56, C57, R23, R25

and

R26

rectify, filter and multiply the basic

200 pA

move-

ment of the front panel meter

to indicate for-

ward and reflected

power.

1 2 ... 20 21 22 23 24 25 26 27 28 29 30 ... 36 37

Comentários a estes Manuais

Sem comentários

DRAKE L7 Manual do Operador Página 25

Comentários a estes Manuais