The Roberts RM33 is the smaller brother of the Roberts RM50 series radio.
The ships broadcast radio receiver Ebay purchase No 120
The RM33 is a 3 band, MW, LW and VHF radio with five preset plus manual tuning. Finished with a Teak cabinet I felt it would be a nice match for the interior of the boat. Not only this, but being a table top radio the control panel is on the side of the box, and not as usually placed, on the top as in a portable radio.
The bigger brother RM50 features Bass and Treble controls plus a larger internal speaker. There was also a more popular RM44 which featured a polished metal front panel. However these extra features makes for a larger radio which I felt would be too large for such a small boat.
As supplied the unit is mains only, so this will need some modification for operation on 12 volts. It has its own telescoping aerial for VHF work plus a socket for an external aerial. Using the telescopic aerial would also be impractical so use is to be made of the external aerial socket.
One of the things that interested me about this radio is the preset channels. I suspect it will be using Varicap tuning allowing the use of preset potentiometers to set the tuning. As this radio hails from the era of tuning capacitors I can’t help my intrigue to see how they have done this.
More to follow on this as when I get around to it.
Semiconductors (the count is only for transistors) 3:
Principle Super-Heterodyne (Super in general); IF-Freq 470/10700 kHz
Wave bands Broadcast, Long Wave and FM.
Power type and voltage Alternating Current supply (AC) / 240 Volt
Loudspeaker Permanent Magnet Dynamic (PDyn) Loudspeaker (moving coil) – elliptical / Ø 13.6 cm = 5.4 inch
Power out 2 W
Material Wooden case
Shape Tablemodel with Push Buttons.
Dimensions (WHD) 313 x 115 x 125 mm / 12.3 x 4.5 x 4.9 inch
Transistors: BC542, BF495D, BC548B; ICs: TDA5700, TDA2611A. Five VHF presets.