The Philips D-2999 is a desktop shortwave receiver and looks like a amateur radio transceiver; with it's dimensions of 32 x 10 x 25 cm and a weight of 3,7 kg, it can be carried on the carrying handle and is portable in the meaning of the expression, but it's to large and to heave to take on airplane trips.
The set can be powered from 110 / 220 V mains, a 9 - 14 Volts DC source like a car battery or six UM-1 batteries / mono cells; for proper operation, another three UM-3 batteries are needed to operate the radio's microprocessor with the PLL circuitry, frequency memories and the internal clock. Without these batteries, the radio will only make an annoying continuos beeping noise when connected to mains.

One big speaker is facing upwards, a smaller speaker is located behind the speakergrill at the front.

A long row of pushbuttons extends along the upper part of the front panel. The three pushbuttons at the left activate the big speaker, switch the instrument to signal level or battery level indication and activate dial illumination, the pushbutton at the right is the main switch. With all the pushbuttons in between, You can directly access one of the many wavebands from longwaves to the VHF / FM band.
Next to the analog signaL strength meter, You find the LCD frequency / clock / alarm time display, tiny keys just below are used to activate different clock and timer functions.

The small numbered keys are used for direct frequency entry, the receiver accepts frequencies with a dot as MHz frequency entries and switches automatically from AM to VHF FM mode, when You enter frequencies above 88 MHz. Just key in the desired frequency and press the EXECUTE button.
The keys numbered A - D and 1 - 4 are used to adress the frequency memories, each memory channel can be addressed by the combination of a letter and a number, from "A-1, A-2,..., D-4", the receiver can store 16 frequencies in it's memory. Use the pushbutton STORE PRESET followed by a letter/number combination to store the frequency and only the letter/number conbination to recall the frequency from the respective memory channel.
You can detune every operation frequency with the main tuning knob, tuning steps are increased when the tuning knob is rotated faster.

In the bottom row of controls, You find from the left the volume control and the separate bass and trebe controls, two little pushbuttons at the left of the headphones jack switch the narrow and wide AM bandwidth and the attenuator active in the LOCAl position. The other two pushbuttons activate the BFO for CW and single sideband reception and the manual RF gain control.

At the rear of the receiver, You find switchable sockets for external antennas just below the battery compartment, in the middle a DIN cassette recorder and a line out jack. Two tiny switches to activate 12/24 h time display and the 9/10 kHz channel spacing on mediumwaves, the have to be set to the correct position before inserting the batteries.

The Philips D-2999 is a microprocessor controlled double conversion receiver with a high first intermediate frequency of 55 MHz, the mixer signal of 55,164 - 84,999 kHz derives from a high stability PLL synthesizer. The signal is led to the second mixer through a crystal filter, the 468 kHz second intermediate frequency has to pass a ceramic filter and is lead to the demodulator. A BFO gives the possibility of CW and SSB reception.
The set comes without an active preselection so the use of an external preselector or antenna tuner might be helpful when You consider to operate the reciver on long wire antennas.

In practical use, the D-2999 is a good performer when You intend to listen to the signals of the major international shortwave broadcasters. In the amateur radio bands, some strong CW and SSB signals of nearby ham can be copied easily, You have to operate the BFO control quite carefully, but the set has no fine tuning control, so ECSS reception is difficult and often does not really improve faint signals reproduction.
The bottom line: the D-2999 - when it can be found for a reasonable price in the used market or online auctions - is a good performer as an entry level DXers receiver. It is not really the kind of set You want to carry with You on trips abroad, for this purpose, a Sony ICF-7600D will do the job and will easily outperform the D-2999.