Short-Wave (Shortwave)

Eddystone Shortwave Receiver

Plug-in coils provide a wide wave range. The reaction is controlled by a potentiometer and variable condenser.

There are comparatively few shortwave receiving sets on the market, and although amateurs interested in shortwave reception usually construct sets for themselves, there is a considerable demand for a made-up shortwave set. A complete two-valve short wave receiver is manufactured by Stratton & Co.,

The circuit arrangement employed is most universally adopted by amateurs and comprises an aerial coil, inductively coupled to a tuned closed circuit with a variable capacity reaction. To cover a wide range of wavelengths interchangeable plug-in coils must be adopted, and the simple form of coil mount which is fitted is a feature of the set that will recommend it to the shortwave enthusiasts. It comprises a series of sockets arranged along an ebonite strip, some of which are connected across in order to accommodate the pin connectors of coils differing in length. The coils are of No. 16 enameled wire rigidly supported between ebonite strips, and although only a minimum of solid dielectric material is used in the construction the coils are perfectly durable and robust. Coils and coil holders are obtainable if required as separate components. The high-frequency choke coil connected in the plate circuit of the detector valve is also of special construction, and as well as being provided with a two-pin mount, is an air-spaced winding carried on ebonite rods.

An unusual and attractive feature is that of employing a glass panel for carrying the controls, which, as well as displaying a well-finished interior, permits of the tuning coils being viewed so that the tuning range can be estimated. In addition to the reaction condenser a control of self-oscillation is provided by a potentiometer connected to the grid leak. If the size of the reaction coil is not suitably chosen some degree of over-lap may occur when adjusting the reaction condenser close to the oscillating point, and the potentiometer will be found useful for providing a critical adjustment under such circumstances, though a slight falling-off in signal strength results when the valve becomes an anode band detector by b e i n g negatively biased. This receiver is suitable for the reception of amateur transmissions, and on test both 2XAh and KDKA were readily tuned in at 'a. satisfactory telephone strength signals being easily separated from the heterodyned carrier wave.

Oak cabinet.
Was followed by the revised model of the  "Atlantic Two" (Short Wave Two).

Donde encontrará 255 modelos, 125 con imágenes y 46 con esquemas.
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