This radio has a bakelite cabinet and employs following tubes: 12SA7, 12K7GT, 12SQ7, 50L6GT and 35Z5. In the rear part of the cabinet a loop antenne is providing antenna signal to the radio.

I bought this radio at the annual "Rock around the Jukebox" happening in the "Autotron" in Rosmalen in The Netherlands.

  

Judging from information in Rider's manual (Volume 11- page 22) the chassis is a DL type and the model number is 330. IF frequency is 455 kHz and one band is covering 540-1600 kHz.
The schematic and parts list are shown in Beitman's "Manual of 1941 Most Popular Service Diagrams" (thanks Antonio from Portugal), which reveals the likely year of origin of this radio.

The primary coil of the first IF transformer appeared to be interrupted. The DC resistance was about 2 kohm instead of the 30 to 50 ohm which I measured on the other ones. A coil from the junk box with an inductivity of several mH was converted into a coil of 1.84 mH by removing the necessary amount of windings and placed on the position of the defective coil.

The coil at the lef is original. At the right hand side of the coil core the replacing coil can be seen.

Most paper capacitors had too much leak. The interior of these capacitors was removed and replaced by high quality capacitors of the proper value. Thereafter the paper tubes were closed with a kneadable two-component epoxy. The same procedure was followed for the electrolytic capacitor.

All parts on top of the chassis (IF cans, speaker and tuning capacitor) were removed and cleaned and the chassis itself was cleaned as well. The bakelite housing and the two knobs were cleaned and polished with a car cleaner (product available in car shops in The Netherlands: Commandant 4).

The IF transformers were peaked on a signal of 455 kHz from a signal generator. Hereafter the radio played again and showed up a very good sensitivity. An external antenna is even not really necessary.

Unfortunately the back panel was missing. A collector was so kind as to send me a picture, so I will be able to reconstruct it.


E-mail comments to:  mail@oldradios.nl

Last update:  December 21, 2005