GB2180121A - A portable device for use by a news reporter - Google Patents

Abstract

A portable device to be carried by a reporter and coupled to a telephone line at a location from which the reporter wishes to transmit a report to a broadcast station to be broadcast live is disclosed. The device has a casing with a microphone jack (1) for voice input, a tape input (2) for receiving a tape signal and a monitor jack (3) for providing an acoustic signal to the reporter. Voice-controlled gain adjustment (20) and amplification (5) is provided and the device is coupled to the telephone line by a hybrid transformer arrangement (7 to 14). The device has its own power supply in the form of batteries or a connection for an AC mains auto supply. <IMAGE>

Description

SPECIFICATION A portable device for use by a news reporter This invention relates to a portable device to be carried by a sender, for example a news reporter, and for coupling to atelephone linefortransmitting signals between the sender and a remote receiver connected to the telephone line.

It is often desired for a reporter in one location to transmit to a broadcasting station in another location a report of events occurring in the one location. The broadcasting station then broadcasts the report live, i.e. as it is received from the reporter. Generally, this is doneviaatelephoneline using anexistingtele- phone instrument. The quality ofthe signal received overthetelephone line is restricted by the electronics provided in the telephone instrument. Currently available instruments are designed to give a level of performance which is not sufficient for broadcasting, since the signal received over the telephone line may be subject to distortion in excess of a level acceptable for broadcasting.It is therefore necessary to provide in the broadcast station equipment for processing the signals received over the telephone line from the reporter in orderto obtain a signal suitable for broad- casttransmission. Often the signals obtained over the telephone line are unsatisfactory for broadcast transmission even after processing. Further,where such live reports are required, it is necessaryforthe broadcast station to be suitably equipped, with equi pmentwhich is often bulkyandexpensive.

A particular problem during such live reports is that the voice level ofthe reporter may fluctuate con- siderably, causing problems for the processing equi- pment where the signal is to be broadcast by the broadcasting station.

According to one aspect ofthe present invention, there is provided a portable device to be carried bya sender and forcoupling to a telephone linefortransmitting signals between the sender and a remote receiver connected to the telephone line, the device comprising a casing having:: an inputfora voice signal; voice-controlled gain adjustment means coupled to said input for adjusting the voice signal to provide an output signal with reducedamplitudefluc- tuations; first coupling means for coupling the output ofthe gain adjustment means to the telephone lineforsen- ding to the remote receiver said output signal in a form suitable for broadcast transmission; second coupling meansforcouplingtothetele- phone line for receiving a signal from the remote receiver.

Preferably, there is an amplifier coupled to the second coupling means to amplifythesignal received thereby.

In a preferred embodiment, the first and second coupling means are inductive.

According to another aspect of the present invention there is provided a portable device to be carried byasenderandforcouplingtoatelephonelinefor transmitting signals between the sender and a remote receiver connected to the telephone line, the device comprising a casing having:: an inputforavoicesignal; first coupling means for inductively coupling the input to the telephone line for sending to the remote receiver said voice signal in aform suitablefor broadcast transmission; second coupling means for inductively coupling to the telephone line for receiving a signal from the remote receiver, the first and second coupling means comprising transformerwindings, and a cross-over coupling arrangement for reducing that portion of the transmitted voice signal which is coupled from the first to the second coupling means so that it does not affect the signal received from the remote receiver.

According to a further aspect of the present invention there is provided a method of communicating via a telephone line by transmitting a voice signal via the telephone line to a remote receiver and by monitoring signals sentfrom the remote receiver byway of the telephone line, the method comprising the steps of: subjecting said voice signal to voice-controlled gain adjustment to reduce amplitude fluctuations of the said voice signal; transferring said adjusted voice signal onto the telephone line; simultaneously monitoring said telephone linefor received signals; and transducing said received signals into acoustic signals.

For a better understanding ofthe present invention, and to show how the same may be carried into effect, reference will now be made, by way of example,to the accompanying drawings, in which Figure lisa block diagram of one form of a portable device to be carried buy a reporter; Figure 2 illustrates an am piifier which may be addedfora "record-out" signal; Figure 3 illustrates diagrammatically a coupling arrangement where a record-out signal is to be provided; Figure4 illustrates one arrangement which may be used to mixvoice and taped input signals; and Figure 5shows a simpler mixing arrangement.

Figure 1 illustrates one form of a portable device which can be carried buy a reporterand coupled to a telephone line at a location from which the reporter wishes to transmit a report to a broadcast station to be broadcast live. The device is capable of providing a signal which is suitable directly for broadcast transmission at the broadcast station. The report may be spoken bythe reporter, or it may be pre-recorded on a tape and then transmitted.

The device consists of a casing having a microphone 1 for inputting a voice signal from the reporter, a tape input 2 for receiving a taped signal, and a monitor 3 for providing acoustic signals to the reporter derived from signals sent by a remote receiver.

Thus two way communication is enabled.

Avoice-controlled gain adjustment device 20, for example type 6270 manufactured by Plessey is coupled to receive the voice signal from the microphone along input line 4. The voice-controlled gain adjustment device is designed to accept signals from a low output microphone 1 and to provide an essentially constant output signal of 90 millivolts for a 60 dB range of input. The output signal for the voicecontrolled gain adjustment device is fed to an amplifier5,forexampletypeTBA H20M5.The amplifier5 also receives the signal from the tape input 2, frequ encyshifted by means of a capacitor 6. The output from the amplifier 5 isfedto the primarywindings 7, 8 of a firsttransformerTl,these windings 7,8 being connected in parallel.The secondary windings 9,10 ofthe first transformer are arranged so that the wind ing 9 is connectedto thetelephone line,whilethe winding 10 forms part of a cross-over coupling arran gementwith a secondary winding 11 of a second transformerT2. The other winding 12 of the sec- ondarytransformer serves to couple a signal received down the telephone line to winding 13, connected in parallel with winding 14. It is possible to adopt an alternative configuration of thewindings 13 and 14, as discussed later, where a "record-out" signal isto be provided.

The signal coupled into winding 13 isfedto an amplifier 15, the output 16 of which is fed to the monitor 3 for conversion into acoustic signals so that the reporter can listen to the received signal.

The transformer coupling arrangement (7 to 14) serves to cancel unwanted components ofthe signal to be sent down the telephone linefrom that to be received from the telephone line. This cancellation occurs since the output signal from the amplifier5 is fed in phase to windings 7 and 8, so that an unwanted component ofthe signal which couples to wire 13 is in phase with that in wire 7, while the unwanted component coupled to wire 14 is, by virtue of the crossover arrangement, out of phase with that in wire 8.

Accordingly,the unwanted components are substantially cancelled atthe second transformerwindings 13 and 14. If itwere possible to obtain perfect matching ofimpedances,total cancellation would be effected. However,the impedance of a telephone line will vary, and it has been foundthat by inserting a resistor 19 having a nominal value of 620fl in series with the winding 10 a good degree of cancellation is obtained for medium range telephone calls. A lower value (e.g.400- 500Q) is suitablefor "local" calls,and a higher value (erg. 700 - 800Q) for "long distance" calls. Itwould be possibleto provide a variable resis- tor here for adjustment by a user to achieve the best possible cancellation for each location.If total cancellation is not achieved, the sender will be able to hearthe signals which he is transmitting, which may be desirable in some cases.

The portable device can be carried by a reporter and can be connected directlyto a telephone line or to hand-set terminals in any convenient location.

After dialling, thetelephone instrument may be hung up. the signal received down the telephone line is amplified bytheamplifier15,and isfedto monitor3 so that the reporter can listen to information being transmitted to him from the broadcast station. He can then transmit information to the broadcast station by either speaking into the microphone 1 or by providing a taped signal from a tape recorder atthetape input 2 to transmit that signal down the telephone line. The recorded input from the tape input 2 could in theory be fed to the voice-controlled adjustment device, but in practice it is not found to be necessary since the recorded output will not normally be sub- jectto the fluctuations present in a voice signal.The device enables a reporter transmit down a telephone line audio information (from a tape or microphone),withthesignalsuppliedtothetelephoneline being of avert high qualityand so suitablefor broad casttransmission at the broadcast station. The unit therefore enables interviewers to conduct question and answer reports live or pre-recorded for immediate broadcast.

It is possible to provide a device which provides a "record-out" signal which will enable a tape or casette machineto record the transmitted and received signals. Figure 2 illustrates a record-out amplifier 17, e.g. LN741 foramplifyingtherecord-outsignal.

Figure 3 illustrates the transformer winding arrangementfor use with such a device, from which a dif ferent arrangement ofwindings 13, 14 ofthe second transformerT2 can be seen. The record-outamplifier 17 receives the signal from winding 14 of the second transformer at its inverting input, and from the voicecontrolled gain adjustment device at point 18in Figure 1 at its non-inverting input. Thus, the received signal (on winding 15 is mixed with the signalfrom thetape2and microphone 1 inthedifferentialampli- fier 17 in such a waythatthese signals are in phase and balanced to give a combined record output of both send and received signals.The take-off point 18 may be "upstream" of the 1 OKQ resistor 25: the resistor 25 has the effect of producing a drop in level of about3dB.

Mixing of the voice and taped input signals may be effected by the arrangement shown in either Figure4 or Figure 5.

In the arrangement of Figure 4thetape input2 and voice input 1 (after voice controlled gain adjustment in device 20) are fed to an operational amplifier 21 connected as a summing amplifier with unity gain.

The amplifier may be, for example type LM741 The output ofthe amplifier 21 is fed to the amplifierS (Figure 1) or, if no further amplification is required, directly to the transformer T1.

In the arrangement of Figure5,thetape input 2 and the voice input 1 (aftervoice controlled gain adjustment) are fed directly to the non-inverting input of the "record-out" amplifier 17 (Figure 2). The "record- out" amplifier 17 performs the mixing function. The signal forthe amplifier5 (Figure 1) is taken from a potentiometer 22 connected between the output of device 20 and ground to enable gain control to be effected. While the differential amplifiers described herein are of the type LM741, it will be appreciated that any suitable amplifier may be used. Some ex amples are 071,3140E, SL561C and 5534.

It may be possible for some applications to effect a form of voice controlled gain adjustment by using a low noise pre-amplifierfor amplifying the voice input, with an operational amplifier and FETdevice.

A particular advantage of the unit is that it can be housed in a small durable case made of plastics material and measuring 1 10mum x68mm x33mm.

The casing may have connection for an a.c. voltage supplyand/ora battery. Respective LEDsonthecas ing can indicate when the power is on and when the battery needs replacing.

It is also possible to provide a level indicator, for example in theform of an LED having two flashing modes, one for indicating the correct level and the otherforindicating a level some 2 or3 dB in excess of the correct level. The inputforthe indicator could be at any convenient location, for example point 26 or27 in Figure 1.

The portable device may be connected directly to the telephone line using a conventional jack or to the handsetterminals.Thetelephone handset may be hung up after dialling, and the reporter can then monitor incoming signals using a pair of headphones at the monitor3.

Claims (8)

1. A portable device to be carried by a sender and forcoupling to a telephone linefortransmitting signals between the sender and a remote receiver connected to the telephone line, the device comprising a casing having: an inputforavoicesignal; voice-controiled gain adjustment means coupled to said inputfor adjusting thevoice signal to provide an output signal with reduced amplitude fluc- tuations; first coupling means for coupling the output of the gain adjustment means to the telephone line for sen dingtothe remote receiver said output signal in a form suitable for broadcast transmission; second coupling means for coupling to thetelephone line for receiving a signal from the remote receiver.

2. A device as claimed in claim 1,whichcom- prises an amplifier coupled to the second coupling means for amplifying the signal received thereby.

3. A device as claimed in claim 1 or 2 in which the first and second coupling means are inductive.

4. Adevice as claimed in claim 3, in which the first and second coupling means comprise transformer windings, which includes a cross-over coupling arrangement for reducing that portion of the trans mitted voice signal which is coupled from the first to the second coupling means so that it does not affect the signal received from the remote receiver.

5. Aportabledeviceto be carried byasenderand forcouplingtoatelephonelinefortransmitting signals between the sender and a remote receiver connected to the telephone line, the device comprising a casing having:: an inputforavoicesignal; first meansforinductively coupling the output of the first amplifierto the telephone line for sending to the remote receiver said voice signal in a form suitable for broadcast transmission; second means for inductively coupling to thetelephone line for receiving a signal from a remote receiver, the first and second coupling means compris ingtransformerwindings; and a cross-over coupling arrangement for reducing that portion of the transmitted voice signal which is coupled from the first to the second coupling means so that it does not affect the signal received from the remote receiver.

6. A portable device substantially as herein before described with reference to the accompanying drawings.

7. A method of communicating via a telephone line by transmitting a voice signal via the telephone line to a remote receiver and by monitoring signals sent from the remote receiverbywayofthetele- phone line, the method comprising the steps of: subjecting said voice signal to voice-controlled gain adjustment to reduce amplitude fluctuations of said voice signal; transferring said adjusted voice signal onto the telephone line; simultaneously monitoring said telephone line for received signals; and transducing said received signals into acoustic signals.

8. A method of communicating via a telephone line substantially as herein before described with reference to the accompanying drawings.