1.Description

The SM 1008 wireless microphone system consists of a battery-operated miniature transmitter, Model SK 1008, which can be equipped with several different special microphones, and the battery/AC operated receiver, Model

0 EM 1008, which can be operated with a variety of special antennae.

1.1Model SK 1008 Mikroport transmitter

The Mikroport transmitter is operated trom an ordinary 9 V battery, Standard units are designed for two trequencies:

36.7and 37.1 MHz. Two plug-in micro- phones and seven special microphones, which can be connected via short leads, permit adaptation to even unusual appli-

cations. A plug-in antenna is supplied with the transmitter.

1.2 Microphones

 

Two different plug-in microphones may

 

be combined with the Mikroport trans-

 

mitter into a single unit. The combi-

 

nation, which is no larger than a con-

 

ventional microphone, may be either

a

held in the hand or used as a lavalier

microphone via its built-in cord.

Model MD 1008 plug-in microphone,

 

which has spherical characteristics, is

 

preferable whenever it is essential to

 

obtain minimum sensitivity to vibration,

 

and where (especially during interviews)

 

several persons speak into the micro-

 

phone trom different directions. However,

where there is a high ambient noise level, reverberation, or the possibility of acoustic feedback, it is recommended that the Model MD 4008 plug-in micro- phone, which has super-cardioid directional characteristics be employed. Where concealment of the transmitter

is desired, special microphones may still be used, connected to the micro-

phone socket of the SK 1008 transmitter via a short cable. The most frequently used unit, for this application, is the Model MD 214/1 Lavalier suspension microphone. Besides double internal suspension, which renders this microphone strongly resistant to noises produced by friction, the Model MD 214/1 dynamic lavalier microphone has a shaped frequency response that compensates for attenuation of high frequencies caused by the chin of the speaker. The Model 405-T directional hand-held microphone can be used in a similar fashion, worn in an outside pocket, permitting the transmitter to be switched on and off by means of the switch on the microphone. The Model

MM61-2 fountain pen microphone and Model MM 24-2 lapel microphone are even more inconspicuous, although their transmission quality is not as good as that of the previously-mentioned microphones. Where stringent quality requirements exist, the Mikroport trans- mitter mayaiso be connected to one of our transistorized capacitor micro-

phones via a special cable, Model KAM-1. Either the Model MKH 104 with

spherical characteristics, the Model

MKH 404 with cardioid characteristics, or the Model MKH 804 with ultra-direc-

tional characteristics, may be employed.

Power for these microphones is obtained from the Mikroport transmitter battery.

1.3Model EM 1008 Mikroport receiver

This newly-developed receiver may be operated from the AC line or from a standard 9 V battery. The two antenna inputs (60-ohm and 240-ohm impedance) permit the use of different antennae. Transmitter field strength can be continuously monitored with its built-in meter. A balanced, ungrounded 1.55 V audio output provides a signal at less than 2 % distortion. The signal may

also be monitored simultaneously at variable volume via a built-in loud-

speaker.

1.4Antennae

The wire antenna supplied with the Mikroport receiver does not have the same reception performance as the Model TA 203 telescopic accessory antenna. If a Ionger antenna cable is required, e. g., for diversity reception, (See Section 4.1), it is recommended that a tuned 240-ohm dipole be prepared with a cable of suitable length.

2. Preparing the equipment for operation

Reliable operation of the entire system can only be guaranteed by the manufacturer if all parts used are original Sennheiser products and no unauthorized alterations have been made by a third party.