Internal Modifiable Functions, Operation

Operation

1.Turn on the Power switch and set the Manual/Auto switch to Manual.

2.Set the Peak/VU meter to Peak or VU as desired.

3.The 1 kHz internal tone oscillator can be used to help align the following equipment levels (master mixer, amplifier, re- corder, etc.) to the output level of the FP410.The tone oscil- lator is activated by pulling the Master gain control outward. Its level at the FP410 output is set by the Master gain con- trol. After setting equipment levels, turn off the tone oscilla- tor by pushing the Master gain control inward.

4.“Talk” the microphone connected to the FP410 Channel 1 input, and slowly raise the Channel 1 Gain control to the point where the green LED flickers regularly with normal speech, and the red LED only occasionally with louder speech peaks.

5.Set the other FP410 channel gains in the same manner.

6. Set the Flat ( )/Low--Cut () switches adjacent to each Gain control as required. The low--cut position reduces pick- up of low--frequency room noise.

7.Set the Manual/Auto switch to Auto. In about one second, unused microphone inputs will turn off and the level of an in- dividual talker’s voice will rise above the background noise and reverberation to become clearer and more intelligible.

8.Adjust the FP410 Master Gain control for the desired output level, as indicated by the Peak or VU meter, or by the follow- ing equipment.

9.The FP410 is now ready for operation.

USING AN EQUALIZER/FEEDBACK CONTROLLER WITH AN AUTOMATIC MIXER

When setting up a sound system which has an outboard equalizer or feedback controller in the signal chain, set the FP410 to MANUAL. This activates all microphone inputs, so every possible feedback path is open. With the FP410 in MANUAL mode, equalize the sound system and/or “Ring Out” the room to set the feedback controller.

After equalization is complete, set the FP410 to AUTO- MATIC mode. Remember that the input of an automatic mixer drops by 3 dB every time the number activated inputs doubles. When using an FP410 in MANUAL mode, the master output drops by 9 dB when all 8 inputs are activated. Conversely, it will rise by 9 dB when switched back to AUTOMATIC mode.

MODIFIABLE FUNCTIONS

The FP410 is ready for automatic or manual operation as supplied. Additional versatility is provided by easily accessible switches visible when the battery compartment is removed. Note that the switches are all in the “up” position as supplied; changes are made by moving the switch or switches down- ward. The switch positions are illustrated by a label below the battery compartment (see Figure 2).

VU Meter (Switch No. 1). Change the VU meter, supplied cal- ibrated for +4 dBm = 0 VU, to +8 dBm = 0 VU by moving this switch downward. (This switch does not affect calibration of the LED output level meter in the Peak position.)

Limiter Threshold (Switch Nos. 2, 3). Change the limiter threshold, the output level at which limiter action begins, from the factory--set +16 dBm to either +8 dBm, +4 dBm or 0 dBm output level by moving these switches as shown in Figure 2. Off-Attenuation(Switch No. 4). Change the off--attenua- tion from 13 dB to infinite () by moving this switch downward. With the 13 dB setting, an unused microphone is 13 dB lower in level than when it is activated. With the  setting, an unused microphone is completely off.

Hold Time (Switch No. 5). Change the hold time, the duration of time an activated microphone (which is not locked on) re- mains on after the talker stops talking, from 0.4 seconds to 1.0 second by moving this switch downward.

Last Mic Lock-on Defeat (Switch No. 6). The last mic lock--on feature keeps the most recently activated microphone open until a newly activated microphone takes its place. It can be defeated so that all microphones automatically turn off after the hold time by moving this switch downward.

Phantom Power (Switch No. 7). Phantom power for con- denser microphones, normally 14 V, can be changed to 48 V by moving this switch downward. CAUTION: Make certain the condenser microphones to be used are compatible with the selected voltage. If the microphones can operate properly with 14 V phantom power, that position should be used to avoid ex- cessive battery drain.