Page 4-2
V10/V7.5/V5/V3.5 Installation and Operation Manual
Issue 3.5
Section 4 Testing and Adjustment
The exciter, IPA (entire module for
V10/V7.5, individual PA for V5/V3.5), IPA
power supply (ganged with IPA module for
V10/V7.5, independent for V5/V3.5) and
fan supply modules may be duplicated and
connected as active (main) and reserve
(standby). The transmitter control/display
panel’s GUI provides selection of the active
exciter/IPA/ IPA PS/fan PS (A or B). The
following list identifies the duplicated
assemblies and which are active for a
specific selection. LVPS modules U11 and
U12 are connected in parallel and are
always on together. See Figure 4-1 to
locate transmitter modules/assemblies.
A Side Modules
A – Exciter......................................................A14
A – IPA Module (V10/V7.5)............................A19
A – IPA PA (V5/V3.5)................................ A19A4
A – IPA Switching Power Supply Module........U1
A – Fan Supply Module .................................U13
A – LVPS Module...........................................U11
B Side Modules
B – Exciter......................................................A15
B – IPA Module (V10/V7.5 only)....................A20
B – IPA PA (V5/V3.5, dual PA only) ......... A19A3
B – IPA Switching Power Supply Module........U2
B – Fan Supply Module .................................U14
B – LVPS Module...........................................U12
4.3.2 Test Equipment Required
A dummy load, rated for a minimum of
15,000 W for V10, 10,000 W for V7.5,
7,500 W for V5, 5,000 W for V3.5, and a
digital multimeter are required to perform
the functional test procedures. See Table
1-2 for recommended test equipment.
4.3.3 Test Prerequisites
Complete the following before performing
any of the functional test procedures:
(a) Verify nothing that would affect the RF
power stage has been changed since
the last time the initial start-up
procedure, described in Section 2 of
this manual, was completed.
(b) Switch off ac power at the service
entrance.
(c) Terminate the transmitter's RF output
into a precision, 50
Ω
, resistive,
dummy load that is able to accurately
display the RF power applied to it.
WARNING
If a jumper is placed between the
interlock inputs (TB1-1 and TB1-2) on
remote interface PWB A44, safety
features provided by the external
interlocks will be disabled. A fail-safe
method of alerting personnel to this fact
should be implemented. Voltages
dangerous to life are present on RF
output stages and the antenna system
when the transmitter is turned on.
(d) Close all external interlocks or connect
a temporary jumper wire between
TB1-1 and TB1-2 of the remote
interface PWB.
NOTE
Remote interface PWB A44 is the upper-
most PWB on the panel behind the silk-
screened cover.
(e) Obtain the Proof of Performance test
results and the completed copy of the
Critical Parameters sheet, taped to
the tray in front of IPA module A
(A19). For future reference, store
these documents with section 5 of this
manual or in the Repair Manual’s
binder.
NOTE
The data in the Critical Parameters sheet is
compiled at the factory with the transmitter
terminated in a precision 50
Ω
dummy
load. Measurements made on site into a
dummy load or the station antenna may not
yield the same readings. Slight variances
are acceptable. The data is provided as a
routine maintenance and troubleshooting
aid.
