Philips D2935

 This receiver uses digitally synthesised tuning from 150kHz to 30MHz and FM Band II

The shortwave broadcast bands can be selected by stepping through the complete list and specific frequencies selected by using the numbered keys on the panel but only 9 memories are provided which is far too few for this type of set. A BFO is provided for SSB reception as well as a manual RF gain control, essential for best SSB results. There is no means of selecting bandwidth which is a shame although frequency stability is good enough to use a single sideband technique along with the tunable BFO to reduce adjacent channel interference. Tuning rate is two speed governed by the spin speed of the tuning knob.

Annoyingly, FM reception is not stereo and the S-meter does not work for FM

The biggest drawback with the set is the on-off switch. It is impossible to pack the set in a suitcase without the on/off switch becoming operated. When you take the set anywhere it is therefore essential to remove the six "D" size batteries to avoid strange noises from your luggage.

With digitally tuned sets one can set the frequency directly to a short wave broadcast station and, if skip is right, you'll hear it immediately. With shortwave reception, radio signals bounce off the ionosphere and the ground or sea. Depending on the height of the particular section of the ionosphere affecting the frequency you are tuned to, you will hear stations at different distances from you. The frequency at which a section of the ionosphere affects the shortwave signal depends on a number of factors. The main one of these is the effect of the sun. The sun's radiation produces a number of reflective mirrors high above the earth's surface. Some frequencies will pass straight through some layers but others will reflect completely and bounce down towards the earth. The resulting reflected signal may travel skywards then bounce back off the ionosphere again. This process may continue until a signal has travelled all the way round the earth. Occasionally you can hear two or more signals giving an echo effect when they have bounced around the earth in different directions to both appear at your aerial. Because one may take longer to reach you, you get the echo effect.

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