Manufactured by National Panasonic.
Only shortly after Sony had presented its ICF-7600A and Toshiba the RP-F11L travel portables, Panasonic presented the double conversion superhet RF-B50 in 1984. In a similar arrangement to the analogue world receivers mentioned above, the relevant shortwave bands can be tuned on a bandspread dial with an accuracy of about 25 kHz, a small red LED acts as tuning indicator. The selection of two different IF bandwidths makes a significant difference to the competing sets.
- Principle: double conversion, IF 11850 / 450 kHz / FM 10.7 MHz
- Frequency range: FM, LW, MW, 7 x SW (49 - 13 m band)
- Frequency dial: analogue dial, approx. 25 kHz
- Frequency memory: none
- Signal strength indicator: Tuning LED
- Features: Attenuator
- Sensitivity: AM (A3) 4.3 μV / Selectivity: narrow 3.3/9.8 wide 6/20 kHz (-6/-60 dB)
- 185 x 112 x 35 mm, weight 0.53 kg
The Panasonic RF-B50L is shortwave travel portable, the double conversion set comes in a quite compact cabinet with the dimensions of a pocket book, 185 x 112 x 35 mm / 530 g.
The international variant RF-B50 covers FM, MW and a tropical bands shortwave range 120 - 60 m (single conversion in this range), the European variant RF-B50L covers FM, medium- and longwaves, both sets come with seven common shortwave broadcast bands (49 - 13 m) with a bandspread arrangement and an analog tuning dial.
The silver coloured plastic cabinet with the red decorative stripes on both sides of the dial give an elegant appearence to the set.
Behind the speaker grill at the left side of the receiver's front panel, you find a 7 cm diameter speaker. At the right, you find a tiny red glowing LED as signal strength indicator, just below the bandswitch pushbuttons for FM, MW, LW and shortwaves, the selected band segment is indicated by another LED. The power switch in the right lower corner is a sliding switch a little bit recessed in the cabinet, this will prevent the radio to be inadvertently switched on in your suitcase during a flight.
In the middle of the frontpanel, you find the analog bandspread dials for all shortwave broadcast bands, frequencies can be read with an accuracy of around 25 kHz. A tiny red marking is moved mechanically to indicate the active band selected with the sliding switch just below. Another switch selects the two I.F. bandwidths, the set has sliding controls for tone and volume.
At the right small face of the receiver, you find the tuning knob, in contrast to cheap shortwave radios from the discounter, tuning is accurate and without backlash. At the left small face, you find the sockets for earphones and a center-negative 6V DC power supply. In contrast to the German variant, the European model in my hands comes with antenna connectors at the rear face with a speacial type of plug.
Panasonic's RF-B50 is easy to operate, like the Sony analog shortwave radios. Set the main switch to ON, press the SW button, the BAND SELECTOR in position 1 will select the 49 m shortwave broadcast band. Look out for the news coming from Cologne somewhere between the 6.05 and 6.10 frequency marks, and you are tuned to 6075 kHz. In case of an interference from an adjacent channel station, switch to the narrow filter, that's it…
The sensivitity of the RF-B50 is good, selectivity is above average when switched to the narrow IF filter. Thanks to the double conversion design, unwanted signals from mirroring 900 kHz below the tuned frequency are not found.
The audio quality is good, the set has no synthesizer hiss as found frequently on cheap PLL synthesized multiband radios - but the lack of a digital frequency display and memories will make this radio a collector's item, nowadays. You can use the set to receive the local stations when you are on a trip abroad, but to stay connected with your home, I would look for a set with digital frequency display.
Double conversion superhet, analogue signal processing.
The set is equipped with semiconductors.