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Philips D 2935

Manufactured by Philips, Eindhoven.

In the mid-eighties, Philips launched two microprocessor-controlled shortwave receivers, in the wake of the microprocessor-controlled Sony ICF-2001. The D 2935 was designed as a travel receiver, the D 2999, which was technically very similar, had the look of a tabletop receiver. Both sets were the only real all wave receivers from Philips, designed to compete with the sets of Grundig and Sony. They were delivered with an operation manual, a shortwave reception guide and a usable frequency list. After this respectable success, only a few analogue travel receivers at low prices with mediocre performance followed.

Philips D 2935

Technical data

Power supply

Dimensions

  • 320 x 180 x 80 mm, weight 3.18 kg

Accessories

Operation

The portable receiver Philips D 2935 with it's dimensions of 32 x 18 x 8 cm tends to tilt backwards, so it has to be held with the other hand, when the keys are pressed; the radio comes with a fold-out stand. With a weight of 3.18 kg (with the 6 UM-1 mono cells for portable operation and the 3 UM-3 AA cells required for memory retention, the receiver has a weight of weighs 3.8 kg. Today, lighter receivers better suited for air travel can be found. The D-2935 with its external DC input (the unit can handle voltages of 9 - 14 volts) is well suited to be carried along in a car or camper. In contrast to the Sony units, the mains adapter, switchable between 110 and 220 V, is built-in.

On the front panel the power switch and the switch for the dial illumination are located in the upper left corner, above the large loudspeaker.

The field strength indicator works only in the AM ranges and is designed with a 5-part LED chain, which reacts quite sensitively and is not calibrated. Below it, on the left, is the large, easy-to-read, illuminated LCD display, which indicates the operation frequency with an accuracy of 1 kHz and the waveband (incl. shortwave meter band). To the right is the keypad for frequency input, below it the tuning knob with magnetic steps, the tuning increment is increased from 1 to 10 kHz when the knob is turned faster.

Below the frequency display, the six keys of the station memories are located, they are marked „Preselection“. In the memoriy channels A1, A2, A3, B1, … C3, a total of 9 frequencies can be stored. In the bottom row, the 4 band range keys, electronic switching is used.

On the right of the upper face of the receiver, three small buttons let you select between internal telescopic and ferrite antenna, activate the attenuator („local“) and the BFO for single sideband reception. Below this the rotary controls for the BFO pitch, the RF amplification „AM Gain Control“, the tone control and the somewhat larger volume control are located. In contrast to slider controls, the rotary controls usually work smoothly and without scratching, even after years of use. On the left face of the unit, one above the other, are the sockets for „line out“ output, to feed to audio signal to a tape recorder or RTTY decoder, the headphones, the 12 V DC input and the mains cable.

The coaxial antenna connectors for AM and FM antennas and the switch to select the internal or the external antennas are located on the right face of the cabinet. The possibility to select between different antennas, together with the switch for the internal ferrite antenna which can be switched off completely, make a positive difference between the D-2935 and other travel receivers.

Technically, the Philips D-2935 acts as a double conversion superhet with a high first intermediate frequency of 55 MHz, the mixer signal of 55.164 - 84.999 kHz comes from a stable PLL synthesizer. The signal is fed to the second mixer through a crystal filter. In the second mixer, the second IF of 468 kHz is generated. Here, the final selection is made with a ceramic filter, a diode detector is used as AM demodulator, and a BFO can be switched in for SSB reception.

There is no preselection in front of the first mixer, which makes the receiver sensitive to long antennas; the use of an external preselector seems advisable when operating on long-wire antennas. In the first version, the IF filter of 6.3 kHz at -6 dB was too wide for shortwave reception in the 5 kHz channel spacing, it was replaced by a filter of 2.7 kHz at -6 dB in the later 'updated' version.

In everyday use, the D-2935 can receive the international services of European boradcasters without any problems. The set has a sufficient separatio in the 5 kHz channel raster, the DW on 6075 with a strong signal causes splatter interference up to 6070 and can no longer be detected on 6068. In the amateur radio ranges, the German amateurs can be picked up without any problems in SSB and CW, even if the tuning with the BFO has to be done with some care.

Finding a station is easy: by pressing the Band Selection button, the waveband is preselected, SW jumps to the 120 m band, with each further press on the button, the next shortwave broadcast band is selected, the 21 m band is also preprogrammed. Within a band, the radio can be tuned with the pleasantly light tuning knob, at high rotation speed the tuning step width is increased to 100 kHz, so a quick change to the upper end of a band is possible without problems.

For direct frequency entry, the desired frequency can be entered directly without a leading zero; with 6 1 5 5 Exec, you end up at Austrian Radio from Vienna, with 6 . 1 5 5 Exec as well. Numbers up to 2 6 . are interpreted as MHz, numbers above 8 8 . as MHz in the FM broadcast band; there is no need for a separate switchover for the VHF-FM mode.

A preset station can be stored by pressing Store followed by the memory designation, for example Store A 1, in the following 5 seconds. By pressing A 1, the station just stored can be recalled later, and as a special feature on the Philips, pressing the B key then switches to memory B 1. The microprocessor control options on the Philips D 2935 can be used intuitively even without extensive study of the operating instructions.

In summary, it can be stated that the D 2935 has solid performance and sufficient audio output , it serves well as a travel receiver when camping, and as a tabletop receiver on the first steps into the shortwave hobby. If you can find one for usually a small amount of money, you would call that good price - performance ratio.

Technical principle

Components

The set is completely solid state.

Technical documentation

Development

Further information

en/d_2935.txt · Zuletzt geändert: 2021/04/19 21:10 von mb