Page 6
Dual ND500II (User Supplied Cabinet) – IS03003
Issue 1.0
Information Sheet
(h)
Connect a 250-watt, precision, 50-
ohm, resistive dummy load to
transmitter A's RF output coaxial
connector (1A7J2), using a customer-
provided coaxial cable.
(i)
Set transmitter B's
POWER
switch to
ON
.
(j)
Set transmitter A's
LOCAL
/
REMOTE
switch to
LOCAL
.
(k)
Set transmitter A's
POWER
switch to
ON
and perform servicing and/or testing
procedures on transmitter A.
(l)
Upon successful completion of
maintenance procedures, set
POWER
switches of both transmitters to
OFF
.
(m)
Disconnect the dummy load from
transmitter A’s RF output coaxial
connector (1A7J2).
(n)
Remove the antenna system cable
from transmitter B's RF output
connector (2A7J2) and reconnect it to
the cabinet's RF output coaxial
connector or to transmitter A’s RF
output connector (1A7J2).
(o)
Restore coaxial cables to their original
connections.
(p)
Remove jumper connected in step (c).
(q)
Set
POWER
switch of both transmitters
to
ON
and set their
LOCAL
/
REMOTE
switches to the desired position.
7. CHECK OF CHANGEOVER UNIT
Check the operation of the main/standby
changeover function as follows:
(a)
Verify both transmitters are turned on
and their switches are set as specified
for 'Operating Setting' in table 4-1 of
the ND500II instruction manual.
(b)
Verify transmitter A is producing the
desired RF output and transmitter B's
RF output is inhibited
(
MAIN
TRANSMITTER – SELECT
switch set to
A
).
(c)
Set transmitter A's
KEYING
switch (S1)
to
OFF
.
(d)
After a time delay (between twenty
and eighty seconds), transmitter A's
RF output should be inhibited and
transmitter B should be enabled and
producing the desired output.
NOTE
If A11J4-21 of transmitter B is connected to
ground, transmitter B's 'standby 1' code
variation will be transmitted when transmitter
B turns on.
(e)
Set transmitter A's
KEYING
switch (S1)
to
ON
.
(f)
Reset transmitter A by setting its
POWER
switch (S3) to
OFF
and then
return it to
ON
.
