IE922710A1 - A radio receiver - Google Patents

Abstract

A radio receiver (1) has circuits (5) mounted in a housing 5 (2) which is the same shape as that of an audio cassette. The circuits (5) are for reception of short-wave frequencies which travel over very long distances and to which conventional radio receivers may not be tuned. Output from the radio receiver (1) is from an audio10 inductive coupler (4). The user inserts the receiver (1) into a cassette recorder and on pressing the "Play" button the radio broadcast may be listened to. The invention thus avoids the need for purchase cf a special radio which can receive special frequencies such as short-wave.

Description

broadcasting channel. However, this range of frequencies 5 generally does not include some frequencies which would be useful in certain circumstances. For example, most conventional radio receivers are not designed for reception of broadcasts in the short-wave band which is suitable for broadcasting over large distances.

The obvious solution to this problem is to produce a radio receiver which is tunable to these frequencies. However, a problem with this is that it would be difficult to persuade people to buy such radio receivers if they already own a receiver.

The invention is directed towards providing a radio receiver to overcome this problem.

According to the invention, there is provided a radio receiver comprising a radio reception circuit and an output device mounted within a housing, wherein the output device comprises means for interfacing with a tape reading head.

In one embodiment, the housing is of similar shape to that of an audio cassette.

In another embodiment, the output device is an audio25 inductive coupler. Alternatively, the output device is a stereo tape head. - 2 In a further embodiment, the housing includes sensors connected to the signal processing circuit for control of the receiver. The sensors may be mounted for detection of the orientation of the housing with a cassette player.

Preferably, the reception circuit comprises a means for storing pre-set messages and transmitting them to the output device on reception of an activating radio signal.

The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only with reference to the accompanying drawings in which :Fig. 1 is a perspective view of a radio receiver of the invention, and Fig. 2 is a circuit diagram showing a signal processing 15 circuit of the radio receiver.

Referring to the drawings, there is illustrated a radio receiver of the invention, indicated generally by the reference numeral 1. The radio receiver 1 is not tunable and is dedicated for reception of a single broadcast frequency. The receiver 1 is mounted in a housing 2 which is of the same shape as that of a conventional audio cassette. The receiver 1 also includes a flexible antenna and an output device, namely, an audio-inductive coupler which is in the position for inductive coupling with tape reading heads of a conventional cassette recorder.

Referring to Fig. 2 a reception or signal processing circuit mounted within the housing 2 is illustrated in detail. The circuit 5 comprises a bandpass filter 6 connected to the antenna 3 and which provides a basic selectivity function. This is connected to a preΙε 922710 - 3 amplifier 7 which includes an automatic gain control circuit for minimising the effects of signal excursions and also to ensure that the amplifier operates in a linear fashion so as to avoid cross-modulation and inter5 modulation. The pre-amplifier 7 is connected to a noise gate 8 for removal of interference pulses such as car ignition and other fast rise time pulses. The noise gate 8 includes a series of diodes which are switched from a conducting to a non-conducting mode when a pulse of interference is received. The noise gate 8 is connected to an RF amplifier 9 which is essentially wide-band in nature and is connected to a narrow band filter 10 which selects the desired frequency from it. The output of the narrow band filter is connected to a detection and automatic gain control (AGC) circuit 11 for audio frequency amplification, if required. The signal is then fed to the audio-inductive coupler 4.

Power from the circuit 5 is derived from a small battery located within the housing 2. Alternatively it may be from an external source such as the electrical circuit of a motor vehicle.

In use, the radio receiver 1 may be stored with cassette tapes and if one wishes to listen to radio broadcasting at a particular frequency, the receiver 1 is simply inserted into a cassette recorder just like a conventional cassette tape. On pressing the play button on the tape recorder the reading heads of the tape recorder are coupled with the inductive coupler 4 and the reading heads see a signal which is just like the signal off a magnetic tape passing by the head. It then processes the signal through the tape reading circuitry for output at a speaker. Thus, audio output from the radio receiver 1 comes from a tape recorder such as that conventionally known as a Walkman™ or alternatively a vehicle tape recorder or any other tape - 4 recorder. Accordingly, the radio receiver 1 may be manufactured very inexpensively so that users would wish to buy it so that they may listen to a certain radio broadcast frequency and may simply carry it around together with cassette tapes. This is a major improvement over the prior art as heretofore it would have been necessary to change one's radio to receive an additional frequency, which is expensive, particularly when installed in a motor vehicle.

What has been achieved by the invention is the utilisation of existing equipment to allow users to conveniently listen to a new broadcast frequency, a circuit mounted within a small housing being all that is required. An example of a situation where the invention would be particularly useful is where a person travels abroad and wishes to listen to a home channel broadcast on short wave.

The invention is not limited to the embodiments hereinbefore described. For example, it is envisaged that instead of the audio-inductive coupler 4, a stereo tape head may be used which would be spring-biased for direct contact with the reading head of a tape recorder for the handling of stereo signals. It is also envisaged that two or more frequencies may be received, depending on the construction of the signal processing circuit. For selection of the frequencies, a button may be incorporated into the housing. Alternatively, sensors located at the same position as conventional protection tabs on cassette tapes may be used to detect which side of the tape has been inserted for selection of a channel. It is envisaged that opto-couplers and/or photoelectric cells in close proximity to the sprocket may be used for tuning and it is also envisaged that Hall-effect devices may be used.

IE 922710 - 5 The signal processing circuit of the invention may include a memory for storage of pre-set messages which are outputted on reception of a radio activating signal at the antenna 3.

Many different embodiments of the invention are envisaged, the most important feature of the invention being the use of an output device which interfaces with the reading heads of a tape recorder.

The invention is not limited to the embodiments 10 hereinbefore described, but may be varied in construction and detail.

Claims (8)

1. A radio receiver comprising a radio reception circuit and an output device mounted within a housing, wherein the output device comprises means for interfacing with 5 a tape reading head.

2. A radio receiver as claimed in claim 1, wherein the housing is of similar shape to that of an audio cassette.

3. A radio receiver as claimed in claims 1 or 2, wherein 10 the output device is an audio-inductive coupler.

4. A radio receiver as claimed in claims 1 or 2, wherein the output device is a stereo tape head.

5. A radio receiver as claimed in any preceding claim, wherein the housing includes sensors connected to the 15 signal processing circuit for control of the receiver.

6. A radio receiver as claimed in any of claims 2 to 5, wherein the sensors are mounted for detection of the orientation of the housing within a cassette player.

7. A radio receiver as claimed in any preceding claim, 20 wherein the reception circuit comprises a means for storing pre-set messages and transmitting them to the output device on reception of an activating radio signal.

8. A radio receiver substantially as hereinbefore 25 described with reference to and as illustrated in the accompanying drawings.