Lectrosonics SMa Series, Instruction Manual

SMa Series 

Setting Transmitter 

Operating Frequency 

Frequency displayed 

The Operating Frequency of the 

in MHz 

SM can be displayed either in

MHz or as a two-digit hexadeci­

mal number. (See 

Controls and

Functions, FREQ Button

.)  The

Frequency displayed as 

SM’s operating frequency can 

two-digit hexadecimal 

be set with the unit in Standby 

number 

Mode or powered up for normal 

operation. Use the following procedure to change the 

Operating Frequency of the SM transmitter: 

1)  

If the LCD is displaying something other than the 

Frequency Screen, press the FREQ button on the 

SM Control Panel to enter this screen. 

Note: The default display is in MHz. Pressing 

the FREQ button again displays the operating 

frequency as a two-digit hexadecimal number 

that corresponds the equivalent Lectrosonics 

Frequency Switch Setting. 

2)  

While holding the FREQ button, use the Up or 

Down arrow buttons to move the operating fre­

quency up or down in 100 kHz increments from the 

current setting. 

Note: The operating frequency displayed on the 

LCD wraps as it reaches the upper or lower end of 

its range. Thus, if you intend to move the operating 

frequency from the lower end of the range to the 

upper end, it may be faster to do this by using the 

Down arrow until the frequency wraps to the upper 

end. 

Most Lectrosonics receivers indicate the operating 

frequency both in MHz and as a two digit hexa­

decimal number. This conforms to the Lectrosonics 

tradition of setting the operating frequency using 

two 16-position rotary switches. The SM Series 

units offer the ability to set the operating frequency 

in a similar manner. Pressing the FREQ button 

while the LCD displays the operating frequency in 

MHz will change the display to show the equivalent 

two-digit hexadecimal frequency select switch set­

ting. Simply use the UP or DOWN arrow to increase 

or decrease the operating frequency. 

Adjusting the Low Frequency Roll-off 

Repeatedly press the AUDIO button until the LF roll-

off adjustment screen appears. Then press and hold 

the AUDIO button while selecting the desired roll-off 

frequency with the UP and DOWN arrows. 

Attaching a Microphone and Adjusting Gain 

The control panel Modulation LEDs indicate the modu­

lation level and limiter activity. Once set, the transmit­

ter’s audio level setting 

should not 

be used to control 

the volume of your sound system or recorder levels. 

This gain adjustment matches the transmitter gain with 

the microphone’s output level, the user’s voice level and 

the position of the microphone. The audio input level 

can be set with the unit in Standby Mode or while pow­

ered up in normal operation. 

Signal Level 

-20 LED 

-10 LED 

Less than -20 dB

 Off

 Off 

-20 dB to -10 dB 

Green

 Off 

-10 dB to +0 dB

 Green 

Green 

+0 dB to +10 dB

 Red

 Green 

Greater than +10 db

 Red

 Red 

Note: Different voices will usually require

different settings of the AUDIO 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. 

1)  

With the SM powered off, insert the microphone 

plug into the Audio Input Jack, aligning the pins and 

ensuring that the connector locks. 

See the following page for suggestions on using

the microphone connector and sleeve 

2)  

Place the transmitter in Standby Mode, or if the unit 

is to be powered up and adjusted, mute the main 

sound system prior to powering up the transmitter. 

3)  

Position the microphone in the location where it will 

be used in actual operation. 

4)  

Observe the audio level LEDs while speaking or 

singing into the microphone at the same voice level 

that will be used during the program. While holding 

the AUDIO button, press the UP or DOWN arrow 

buttons until the both the -20 and -10 LEDs glow 

green, with the -20 LED occasionally flickering red. 

This will maximize the signal to noise ratio of the 

system with full modulation and provide subtle limit­

ing to prevent overload and audible compression of 

signal peaks. 

Note: Setting the audio level too high reduces the

dynamic range of the audio signal. Setting the

audio level too low may cause hiss and noise in

the audio. 

5)  

If the unit was set up in Standby Mode, it will be 

necessary to turn the transmitter off, then power it 

up again in normal operation so the RF output will 

be on. Then the other components in the sound or 

recording system can be adjusted. 

The roll-off frequency can be set to 35, 50, 70, 100, 120 

and 150 Hz. 

LECTROSONICS, INC. 

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