Kingston

A new development is now taking place in the form of home recording, so that the radio-gramophone not only serves as a source of entertainment from broadcast or record, but provides a means  for making records of items from the broadcast programme. The process of recording being well known, one might think that the making of a home record making outfit would be a simple matter. This is not the case, however, as there are many practical problems to solve. The first popular home record making equipment has now made its appearance on the market and, known as the “Kingston Home Recorder” is being supplied by The Kingstophone Co., Ltd., 91, Tottenham Court Road, London, W. 1. In spite of the fact that it is a first model there is much evidence that the design has been carefully developed before setting about production.

The entire assembly is made up from castings, pressings and small turned parts, is generously designed, and exceedingly well finished. It is obvious from the design that it is the intention of the manufacturers to go ahead with the production of a large number of home recorders. Primarily, the outfit in its simplest form is intended for making records from speech delivered into a mouthpiece arranged as a horn. The sound is conveyed on to a light aluminium diaphragm, suitably stiffened and adjusted by several annular corrugations. At the centre of the diaphragm a lever is attached which, mounted between adjustable centres, carries a cutting needle at its opposite end. Thus, the sound waves actuate the diaphragm, giving a movement to the lever, which, in turn, vibrates the cutting stylus. The recorder is carried on a pivoted arm free to swing across the record and arranged for lifting clear of the surface. There is a heavy adjustable counterweight which allows of critical adjustment of the pressure of the cutting point on the record. In addition, a second needle point is provided, this being used as a guide in order that the recorder may traverse the record.

In this respect a very simple and effective method is adopted for giving both a traverse to the recorder and a drive for the record with avoidance of slip. The arrangement consists of a l0 in. record carrying a plain spiral, in which the guide point travels. Locked on to the centre of the record by the simple process of engaging on to three studs is the blank aluminium disc upon which the record is to be made. A positive drive is thus obtained under the cutting load of the stylus, while the spiral imparts a cross-movement to the recorder. The spiral on the record plate gives a cross-traverse in respect of some 200 revolutions of the turntable, so that at normal running speed the playing duration is just over two minutes.

Used with a Clockwork Motor.

It is well known that the process of record making normally demands a gramophone motor of generous power in order to avoid a severe slowing up of the turntable when cutting the groove. With the Kingston recorder the aim has been to produce an outfit suitablefor use with the ordinary gramophone fitted, possibly, with but a meagre type of gramophone motor. That this has been achieved is revealed by the public demonstrations which are being given at 245, Tottenham Court Road, London, W. 1, where the recording is carried out on a small portable gramophone. In order to accomplish home recording on a gramophone fitted with a small clockwork motor critical adjustment of the balance weight fitted to the arm is necessary, and the various tests made with the recorder were carried out using an electrically driven turntable.

The process of recording had no appreciable retarding effect, and, in fact, when one came to the recording of broadcast transmissions with an electrical recorder an additional weight was attached to increase the pressure on the record, in spite of the fact that the electrical recorder, with its permanent magnet, is much heavier than the direct sound recorder with its trumpet. Much of the weight is, however, taken by the guide point resting in the spiral, and an increase of pressure is not entirely added to the recorder.

A very interesting evening can be spent making records by speaking or singing into the small trumpet. One must not expect to obtain results comparable with the ordinary record, but nevertheless, speech and music are clear and sufficientlv loud, and from a novelty standpoint the result is quite entertaining. Special needles are provided both for tracking and cutting, whilst a fibre needle must be used for playing, and it is important to keep a good point on the fibre needle in order that it may follow the groove. Detailed instructions are given for recording and playing dealing with the little difficulties which one encounters when starting off.

It is thought, however, that the principal application of home recording is that of using the electrical recorder connected to the output terminals of the wireless set for making recordings of broadcast transmissions. Really good results can be obtained by following the instructions, carefully regulating the pressure on the cutting point at the time of recording. Some experience is necessary in order to get just the right depth of cut in relation to the strength of signal applied to the recorder. Too loud a signal will prevent the playing back of the record, as the needle cannot follow the spiral and successive grooves will overlap. Insufficient pressure will make too light a groove for the fibre needle to follow. It is surprising what good results can be obtained from broadcast transmissions when playing back with a sharp fibre needle. Blank records are supplied suitably etched at the centre for making various entries of the item recorded. The outfit is reasonable in price and costs 45s. for the acoustic model or £3 16s. 6d. for the electrical recording equipment. The electrical recorder may be used as a pick-up.

Among the practical hints that might be offered to one starting off to use the Kingston Home Recorder in conjunction with the broadcast receiver is that of bringing down the signal strength to a lower value than is customarily applied to the loud speaker. The recording needle must be sharp, and should it have become accidentally damaged the substitution of a new and sharply pointed needle is essential. Additional weight on the pick-up is also probably an advantage. Should the guide groove become accidentally damaged the guide plate should be discarded, as every record made will bear evidence of the broken spiral. The gramophone on which the records are replayed must be level excepting, perhaps, when the tone arm is incorrectly mounted, when a slight tilt will assist the point of the needle in following the groove. Of the packet of twelve blank records supplied with the outfit the last six used represent quite good recordings of broadcast items, each giving results when replayed like normal gramophone records, though not quite so loud, while care is necessary in playing them.

British disc records of the 'Acoustic' Era.