LPB OMNI Broadcast Transmitter

Installation Procedure Checklist

Installation Procedure

• Remove Transmitter (and transformer if shipped separately) from Box/Crate and check for external damage during shipping.

• Remove front panel(s) from power amplifier chassis and remove foam shipping pads (See Figure 1).

• Reseat each power amplifier module, as they may have shifted during shipping (See Figure 2).

• Install all power amplifier inihibit switch Tabs (See Figure 3). Do not seat Tabs against Red switches at this time. Make certain that transmitter main power supply breaker is in the OFF position.

• Connect the external power cable to the transmitter.

1. Single (1) Phase (Red -- Black -- Green-Ground)
2. Three (3) Phase (Red -- Black -- Blue -- Green-Ground)

3. Check Voltages across phases. (208 to 220)

Recommended amperage ratings:

• Connect RF OUT to a Dummy Load properly tuned to the carrier frequency of your transmitter. Make sure the load is capable of dissipating 150% of the power available from your transmitter.

• Unplug all connectors on the back of the Power Supply (See Figure 4), turn on the main Circuit Breaker (CB) and check for LEDs on the front of the Power Supply Panel. +16VAC, -16VAC and 24VAC LEDs should be ON. All other LED’s should be OFF.

• Turn off the main CB and connect Control Panel power cable to the back of the Power Supply (J6CNTLR). Disconnect the PDM cable(s) from the Control Panel (See Figure 5).

• Turn on the main Circuit Breaker and check the voltages and LEDs on Control Panel.

+18V should be between 20 to 24V without the Power Amp panel(s) connected. Adjust the transformer taps if required on the low-voltage transformer.

• VAC1, VAC2, VAC3 should all read AC main voltage on a 3-phase transmitter (208 to 220 volts). VAC2 and VAC3 are disabled on a single phase unit.

• 300VDC should read Zero.

• Green ENABLE, LOCK, +18VDC, -18VDC, and MONO LED’s should be ON. Set POWER CONTROL to each setting and verify that correct power LED comes on. Then set POWER CONTROL to 2. The REMOTE LED will be ON only when front panel REMOTE switch is in the REMOTE position.

If Red INTERLOCK LED is ON, check rear door(s) to make sure that they are completely closed and the interlock switches are completely depressed (See Figure 6). Also check that Remote Control Plug J9 - 1 is installed (See Figure 7).

• Check the operating frequency with a frequency counter connected to the Frequency Port (J7 FREQ) on the back of the Control Panel.

• Turn on the high voltage (300VDC) by depressing the ON/RESET button located on the Controller front panel. With no load it should be between 330 VDC and 350 VDC. Adjust the transformer taps if necessary (Refer to technical manual for instructions).

• Press OFF button. Turn off the main CB and connect the Power Amp Panel power cable(s) and the Antenna Interface fan cable (if there is one) to the Power Supply (See Figure 8). Reconnect the PDM cable(s) between the Control Panel and Power Amp Panel(s). All interconnect cables should now be connected between power supply, controller, AIU and all power amp panels.

• Turn Power Control Selector Switch to Setting 2. (See Figure 9). Turn on the main Circuit Breaker and check the LEDs on each Power Amplifier Module.

LED status on each power amp module...

• Red Inhibit LED’s should be ON.
• Green +18 VDC LED’s should be ON.
• Yellow 300 volt LED's should be OFF
• Green RF Output should be OFF
• All fans should be operating.

• Check the Power Amplifier Inhibit Switch operation on each Power Amplifier module by depressing the switch plunger. The Red INHIBIT LED should be OFF when the switch plunger is depressed (See Figure 10).

• Connect a scope to the RF SAMPLE connector on the back of the Antenna Interface panel.

• With all the Power Amplifier INHIBIT switches open (Red Inhibit LED’s ON) turn on the high voltage by depressing the ON/RESET button.

• Check the Manual Power Off by depressing the OFF button on the controller front panel to make sure that it functions correctly. Caution: High voltage capacitors are discharged through bleeder resistors. Dissipation may take several seconds.

• Turn on the high voltage by depressing the ON/RESET button. Yellow 300 VDC LED will come ON. While viewing the oscilloscope screen, carefully depress the Power Amplifier Inhibit Switch on one of the Amplifier Modules (See Figure 10). Caution! Lethal Voltage is present on Amplifier Modules. Use Extreme Care.

• Red Inhibit LED will go OFF

• Repeat process for each Power Amplifier Module. Each module should produce the same output RF power.

• Turn high voltage OFF by depressing the OFF button. Reposition all Power Amplifier Inhibit Switch Tabs and tighten down to hold switch plungers securely in down position. All Red Inhibit LED’s should be OFF (See Figure 11).

• Turn high voltage ON by depressing the ON/RESET button. All Yellow 300 VDC LED’s should be ON (See Figure 12).

• Set FWD/REV Toggle to FWD position. Set the Multimeter Selector Switch to the 300 VDC position. While remaining in Power Setting 2, record the following readings from the three meters located on the controller:

1. Current reading on the 300VDC AMP meter.
2. 300 Volt reading on the VOLT meter.
3. Forward RF Power as indicated on RF % Power meter.

• Turn Power Setting Selector Switch to Power Setting 5. Repeat meter readings. Current and voltage readings should fall within the following ranges:

1. 1 KW Transmitter 3.6 to 4.2 AMPS
2. 2.5 KW Transmitter 9.0 to 11 AMPS
3. 5 KW Transmitter 18.0 to 22.0 AMPS
4. 10 KW Transmitter 38.0 to 46 AMPS
5. All transmitters 300VDC should be in the range of 300 to 330 VOLTS

• Turn Multimeter Selector Switch to +18VDC and -18VDC positions. Readings should fall within the following ranges:

1. +18VDC 18 to 19 VOLTS
2. -18VDC 16 to 22 VOLTS

• Press OFF button on Controller. Turn Main Circuit Breaker to OFF position. Turn Power Setting Selector Switch to Power Setting 2.

• Disconnect Dummy Load from RF OUT connector and connect Antenna to RF OUT connector.

• Turn Main Circuit Breaker to ON position. Turn high voltage on by depressing the ON/RESET button.

• Repeat readings. Readings should be similar to those made into the dummy load.

• Turn FWD/REV Toggle to REV position. Reverse power reading should be less than 2% on the RF % Power meter (Bottom scale on meter).

• Replace front panels on Power Amplifier Panel(s).

• Transmitter is now ready to accept programming. Refer to technical manual for further instructions to attach audio input(s).

Should you have any questions, please contact the factory:

phone 610-825-4100

fax 610-825-4047

email support@lpbinc.com