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OPERATING INSTRUCTIONS

1)

Install a fresh battery according to the instructions on the previous page.

2)

Insert the microphone plug into the input jack, aligning the pins; be sure that the connector locks in.

3)

Attach the antenna to the jack on the bottom of the transmitter.

4)

Turn the power switch to the "MUTE" or "ON" position on the transmitter.

5)

Position the microphone in the location you will use in actual operation.

6)

While speaking or singing at the same voice level that will actually be used, observe the MOD LEVEL
LEDs. Adjust the MIC LEVEL control knob until the LEDs begin to light. Start at a low setting where
neither LED lights as you speak. Gradually, turn the gain up until one LED lights, then the other.

The LEVEL LED lights when the audio level is about 12dB below full modulation. The LIMIT LED lights
when the limiter begins to operate. There is over 40dB of limiting range without overload above the LIMIT
LED, so it is normal that the LIMIT LED light up 5% to 10% of the time during use.

7)

Once the gain has been adjusted, the transmitter audio can be turned on to make sound system level
adjustments. Set the power switch to the ON position and adjust the receiver and/or sound system level
as required.

Please note, there will be a delay between the moment the switch is thrown and the

time when audio will actually pass through to the amplifier.

This intentional delay eliminates turn on

thumps, and is controlled by the pilot tone squelch control.

OPERATING NOTES

The MIC LEVEL control knob should not be used to control the volume of your sound system or recorder levels.
This gain adjustment matches the transmitter gain with the user’s voice level and microphone positioning.

If the mic level is too high -- both LEDs will light frequently or stay lit. This condition may reduce the dynamic
range of the audio signal.

If the mic level is too low -- neither LED will light, or the LEVEL LED will light dimly. This condition may cause hiss
and noise in the audio.

The first LED turns on 12dB below full deviation. The limiting LED turns on at full deviation and indicates that the
input shunt compressor is operating. The input limiter will handle peaks over 40dB above full modulation,
regardless of the gain control setting. The limiter uses a true absolute value circuit to detect both positive and
negative peaks. The attack time is 5 milliseconds and the release time is 200 milliseconds. Occasional limiting is
desirable, indicating that the gain is correctly set and the transmitter is fully modulated for optimum signal to noise
ratio.

Different voices will usually require different settings of the MIC LEVEL control, so check this adjustment as each
new person uses the system. If several different people will be using the transmitter and there is not time to make
the adjustment for each individual, adjust it for the loudest voice.

7

Summary of Contents for UM195

Page 1: ...UM195 BELT PACK TRANSMITTER OPERATING INSTRUCTIONS and trouble shooting guide LECTROSONICS INC Rio Rancho NM ...

Page 2: ......

Page 3: ... source 5 Volts of bias voltage is available to power electret mics with either positive or negative bias Level indicating LEDs are provided on the control panel to make level settings quick and accurate without having to view the receiver The battery compartment accepts any 9 Volt alkaline battery and makes a positive connection via self adjusting contacts The antenna is a detachable locking 1 4 ...

Page 4: ...e time constants are slower low frequency audio distortion will be low but high frequency transients will then be distorted The 195 system introduces an entirely new approach to solving this basic problem called dual band companding There are actually two separate compandors in the 195 system one for high frequencies and one for low frequencies A crossover network separates the frequency bands at ...

Page 5: ...ed until it receives the pilot tone from the matching transmitter even if a strong RF signal is present on the carrier frequency of the system This is extremely important in applications such as with an automatic sound system 75kHz deviation improves the capture ratio signal to noise ratio and AM rejection of a wireless system dramatically compared to the more commonly used 15kHz 75kHz deviation i...

Page 6: ... during this adjustment Even when the switch is turned off or on aburptly the pilot tone muting system prevents thumps or transients from occurring ON LAMP Glows brightly when the battery is good A weak or dim lamp means that the battery is weak and has about half an hour of operation left If the lamp fails to light the battery should be replaced The power lamp should light up in both the MUTE and...

Page 7: ...ver 40 dB Generally speaking some limiting is desirable in normal operation to improve the signal to noise ratio of the system The limiting action is not audible and does not create distortion A highly trained ear would hear only the compression of the peaks in the audio signal which is desirable with most tape recorders and many sound reinforcement systems MIC LEVEL Used to adjust the audio input...

Page 8: ...eries To open the battery compartment press outward on the cover door in the direction of the arrow as shown in the drawing Only firm sliding pressure is needed to open and close the battery door Swing the door open and take note of the polarity marked inside showing the location of the positive and negative terminals You can see the large and small contact holes inside the battery compartment wit...

Page 9: ...tually pass through to the amplifier This intentional delay eliminates turn on thumps and is controlled by the pilot tone squelch control OPERATING NOTES The MIC LEVEL control knob should not be used to control the volume of your sound system or recorder levels This gain adjustment matches the transmitter gain with the user s voice level and microphone positioning If the mic level is too high both...

Page 10: ...enna The UHF UM195 uses a 1 4 wave flexible wire to radiate the RF signal There is really not much difference between these two approaches with respect to the effect of the RF on the microphone capsule Even in transmitters that utilize a dangling wire the microphone is still part of the ground plane and is therefore still in the antenna circuit LECTROSONICS 1 2 3 4 5 Transmitter Input Jack M195 33...

Page 11: ...er mute switch is in the on position NO SOUND OR LOW SOUND LEVEL RECEIVER MOD LEVEL LEDs ARE ON AND VU METER INDICATES AUDIO 1 Receiver output level set too low 2 Receiver output is disconnected cable is defective or mis wired 3 Sound system or recorder input is turned down DISTORTED SOUND 1 Transmitter gain audio level is far too high Check mod level lamps on transmitter and receiver as it is bei...

Page 12: ...43 dB semi log rotary control Modulation indicators Dual LEDs indicate modulation level 12 dB below limiting and at the onset of limiting Controls 3 position OFF MUTE ON slide switch for noiseless turn on turn off operation Front panel knob adjusts audio gain Audio Input Jack Switchcraft 5 pin locking TA5F Antenna UM195 Detachable flexible wire supplied 50 Ohm port allows connection to test equipm...

Page 13: ... exact quotation We will be happy to quote approximate charges by phone for out of warranty repairs RETURNING UNITS FOR REPAIR You will save yourself time and trouble if you will follow the steps below A DO NOT return equipment to the factory for repair without first contacting us by letter or by phone We need to know the nature of the problem the model number and the serial number of the equipmen...

Page 14: ...evelop we will at our option repair or replace any defective parts without charge for either parts or labor If we cannot correct the defect in your equipment we will replace it at no charge with a similar new item We will pay for the cost of returning your merchandise to you This warranty applies only to items returned to us shipping costs prepaid within one year from the date of purchase This war...

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