more receivers to be operated in the diversity mode.Since it is highly unlikely that field strength minima will occur simultane-ously at two different antenna sites, the antennae of the two receiversshould be located at a distance of() several yards from each other. The two receivers must be connected to each

other, the cables provided for diversity operation being inserted into the 'diver- sity'sockets. The equipment connected to the 'output'socket of only one receiver will then automatically be fed by this receiver, or by both receivers in common, when both receive a sufficiently high antenna voltage.

For this application, it is recommendedthat a folded dipole be prepared from 240-ohm TV antenna cable. This is doneas indicated in Fig. 11. A 12 foot long antenna cable is shorted at both ends.Then, one of the two conductors is cut in the center and connected with theconductors of a lead-in cable of anydesired length. The folded dipole thus obtained must be connected to the

anten na socket on the front of the receiver marked '240ohm'.The actual dipole section (12 feet long) should then be vertically oriented.

0

4.2License

The purchaser of this equipment is responsible for obtaining the license tooperate it from the appropriate autho-7 rities.

4.3Special frequencies

While the standard carrier frequencies are set to 36.7 and 37.1 MHz, the system can also be supplied with any two frequencies between 25 and 45 MHz, (with a frequency spacing of 0.3 to 0.5 MHz), as an optional extra.

4.4 Tape recording

Achangeover contact operated by the squelch circuit of the receiver is acces- sible at the 'auxiliarycontact'socket. This changeover contact enables the transports of tape recorders to be

operated by electrical remote control- both by means of the NC and NO

contacts - so that they start when the transmitter is switched on and stop with it is switched off. The circuitry of this contact arrangement can be seen from the diagram located on the rear panel of the receiver.

4.5 Powering external units

A OC voltage of 4 V, at a maximum current of 30 mA, is available at contact 4 of the terminal mentioned in

Section 4.4, for powering external units.

4.62 mV output

If the amplifier or tape recorder used with the receiver does not have a 1.55 V
input, an additional balanced, ungrounded output voltage of 2 mV, with asource impedance of 10 ohm, is available at the contacts 2 and 4 of the

'output' socket. This output can be connected to the low impedance, baian- ced microphone input of an amplifier.

4.7Hum

Since the receiver is al ready connected to ground via the ground contact of the AC power plug, it is essential to prevent ground loops when subsequent amplifiers or tape recorders are con- nected. Regardless of whether the subsequent amplifier has a balanced or an unbalanced input, the shielding of the amplifier cable must be continued to the contact on the amplifier housing. On the receiver side, the screening shielding should remain unconnected and must, therefore, be kept from touching contact 2 of the standard plug.

If, on the other hand, the grounded plug is replaced by a standard plug which does not automatically ground the equipment, it will be necessary for the receiver housing to be directly grounded via aseparate line, or connected via the cable shielding, to the amplifier ground connection. In this

case, the shielding of the cable must be connected to contact 2 of the stan-dard plug on the receiver side.