rAGE
CHART
vn
from
component
side)
SP€AKER
WNNKTED
UECTEO
POSITION
P.A.
TRANSISTOR
CHECK
I
Use the following check to determine whether the P.A.
transistors are defective:
I
1.
Connect an antenna or dummy load to the ANT jack
on the rear panel.
2.
Set your voltmeter on its lowest scale
(1.5V
or higher)
and connect
its
common lead to the chassis.
3.
Depress the SSB, ON and HI buttons. The TUNE
button
must
be released.
4.
Key the Transceiver by using the PTT microphone
switch.
5.
Connect the input probe of your voltmeter first to the
foil of
L952
and then to the foil of
L953.
At each foil
you should obtain the following "normal" reading on
the TX line. If you obtain a "bad" reading, see
paragraph
8
following.
NORMAL
BE
I
TX
(HI
PWR)
0.65V 1.2V
RX
OV 1.2V
6.
Release the HI button and the
PTT
switch.
7.
Repeat the checks in paragraph
5.
You should obtain
the readings on the RX line above.
8.
If you obtain a "bad" reading in either the TX or RX
checks, all four final transistors should be replaced.
These are sold by Heath only as a matched
set
of four
transistors. Refer to "Power Amplifier Warranty" on
Page 281 for the special one-year warranty.
CLOCKWISE
COUNTERCLOCKWISE
~UREO WITH
m
KILOHM
INPUT
VOM
TO
CHASSIS
Figure
4-3
(~e~eat)
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