Antique radio!

A nice antique radio just arrived to be checked, repaired and restored if viable. It is a simple mono radio with volume, tuning and band selector controls.  The back plate is lost, but based in the guts I would say it was built sometime around the 40’s.

 It was a relief to see all the tubes where they are supposed to be, the rectifier UY41, the typical output pentode UL41, diode pentode UAF42, double triode UBC41 and the triode-hexode UCH42.  Although I cannot identify the model, based in the tubes and configuration we find the typical radio modules like detector, audio preamp etc

Is one of those devices designed and built when isolation from supply was not mandatory. That is why it has no power transformer and basically relies in supply voltage level and components impedance, basically five tubes, that is why this kind of radios are known as AA5. It was a way to save money in components and this design comes from the 30's. Back in those days this type radio was designed for 125Vac which is applied directly to the UY41 anode and the series connected heaters of all tubes. It is not a good idea to have a radio around, with this configuration and no back plate, it could be lethal!! Insulation trans and a back cover  is mandatory for this radio.

Components do not look too bad but already tested some of the caps and as expected they have aged, there is also some rusted nodes and degraded wires. Time to check main components and repair the unit.