Barlow's Television Co., P.O.Box 23, New Germany, Natal,
Rep. of South Africa
überarbeitet am 22.7.2010
In 1974, a portable shortwave receiver with the dimensions of a conventional
travel radio got very much attention among the shortwave listeners comunity.
The first time, a circuit developed by Dr. T. L. Wadley for the British
commercial receiver Racal RA - 17 was used in
a travel radio. The circuit was developed by Dr. Wadley who had moved to South
Africa after his retirement and the set has been built by the South African
home electronics manufacturer Barlow's Television Co.
This portable receiver (29.5 x 18.5 (23.5 with carrying handle) x 10cm, 4.3 kg) comes - to avoid interference within the 45-75 MHz range due to the mixing process) in a sturdy metal housing with black imitation leather coating at it's sides. On top of the set, You find a carrying handle with a amall short wave frequency chart folding up underneath. When You unscrew the back lid, You will find access to the battery compartment, where six UM-1 / mono cells will fit in.
The front panel is dominated by the two segment frequency dial. The left thumbwheel indicates the megahertz range - the one on the right the kHz steps. The distance between the 50 kHz marks with it's light green numbers and the 10 kHz lines allows to determine a frequency within the range of 5 kHz. You tune the kHz of a chosen frequency by adjusting the frequency thumbwheel on the right side of the dial window in the middle of the front plate after You have chosen the matching MHz - band.
Next to the frequency dial on the right, You find the signal strength meter moving in a small window, it's calibrated in 1 - 5 divisions. With the small metal knob below the signal-strength meter, You can adjust the oscillator exactly to the displayed frequency when receiving a station on a known and stable frequency.
Further down on the front panel, You find four large rotary knobs. The left bottom knob ist used for switching the set on and activates the volume control, th knob above operates the preselector. It has only some rudimentary marks where to look for the signal maximum once You have tuned in a station. Some preselection is made by micro switches operated with the rotation of the button.
The rotary knobs on the right are used as mode switch (USB (upper side band) / AM / LSB (lower side band); in some Pro versions, You find an additional control to choose the IF bandwidths of 6, 3 and 1,5 KHz. The knob above is used for fine tuning particularly for CW and SSB (ECSS) reception.
The antenna and earth connections are implemented as quite uncommon 3mm sockets on the left top side of the set: On it's left side, You find the sockets for a pair of headphones (3.5 mm) and for an external 9 V power supply.
The 9 cm diameter speaker in the centre of the front panel gives You pleasant audio with it's 0,4 W output power. Don't expect to find further goodies in this straughtforward constructed set like as dial lights, bass/treble control, but this will not bother You successfully tuning in shortwave stations from all around the globe.
The signal path is - like in similar receivers using the Wadley loop - design,
a bit complicated: The incoming signal from the antenna socket will pass the preselector
stage with its ranges 0.5 - 2/2 - 8 and 8 - 30 MHz and first amplifier stage
and will be handed over to the first ring mixer, where the oscillator signal of
45,5 - 74.5 MHz is added. This signal is tuned by means of the "MHz" wheel.
Thus the high first intermediate frequency of 45.2 MHz will result.
The operation is not absolutely simple but can however be learned within minutes -
it's similar to the one found on all other sets using the Wadley Loop circuitry. No
wonder, the set has been designed by Dr. T. L. Wadley after he had settled down in
South Africa after his retirement from Racal:
The Barlow Wadley offers nice audio and a good useable sensitivity to today's
shortwave listener, but usually You will take a smaller less fragile set with
You when You travel abroad. The somewhat inaccurate frequency readout (a detuned
frequency calibration knob, wrong clarifier position won't affect the dial settings)
and the slightly cumbersome tuning scheme will make the set a choice for the collector
and the nostalgic shortwave listener. Battery consumption is very low compared to
the later PLL synthesizer designs, so a set of batteries in Your second shortwave
set will last for weeks or months.
The variant with the FM tuner cannot be found too frequently: the FM tuner module
is attached at the top of the receiver's cabinet and is operated by a pushbutton:
this feature will make the XCR-30 to become a nice holiday radio
My XCR-30 is not meant to replace my Sony 2001D, but it will always merit it's space on my shelves because of it's fascinating circuit, the inconspicuous outside and the amazing reception qualities of this oldie amongst the portable sets.
© Martin Bösch 20.7.2007