This radio was acquired in a garage sale, where still several hundreds of sets were left, after collectors had picked out the most popular items.

It is in a fair condition. Only the dial glass is missing.


The model identification on the back side of the chassis suggests that it is model 533. However, the radio employs 5 tubes plus a ballast resistor. Therefore the model number for this radio should start with a "6". Closer inspection with a magnifying glass reveals that the first digit indeed is a "6".

There is still a mystery to be solved ! According to the schematic in Rider's Manual (page 8-8), model 633 is using the following tubes: 6A7, 6D6, 6Q7G, 25B5, 25Z5 and ballast resistor M-49-B.
My radio, however, does not show up the 25B5 (a direct coupled power amplifier) as output tube, but the beam power amplifier 25L6, which also has a different base than the 25B5. The socket in the chassis has an original imprint "25L6" and there are no signs that the base has been replaced outside the factory.
Is somebody aware of an official modification as described here ???

As the radio did not have visual damages, I cleaned out the interior of the cabinet and applied 110 volts (in small steps). Thereafter on both bands many stations could be heard.


E-mail comments to:

Last update:  December 21, 2005