AWA Radiola 120B Superheterodyne chassis.

This chassis was used in the Radiolette 110/C104 bakelite set and was also sold as the Radiolette 120B bakelite set. The 120B available in a mid sized and full sized wood console.


The valve line-up is 34,34,32,30,30,30.

The tuning dial is marked in both wavelength and frequency.

All the "A" class stations of the day are marked on the tuning dial.

2CO, 7ZL, 3AR, 5CK, 2FC, 6WF, 5CL, 4QG, 3LO, 2BL, 4RK, 2NC.

 

The output transformer is mounted off-chassis. The cable is only around a foot long. The secondary leads of the transformer are quite short, presumably it was mounted on the speaker.

It seems that the speaker was mounted quite close to the chassis, perhaps above? This would indicate that perhaps this particular chassis originally came with the C110 cabinet or the mid-sized 120B console.

Most of the components are held on a tag board. The square metal box contains three low value decoupling capacitors. The pot nearest the front-end adjust the reaction for the local oscillator whilst the other pot controls the volume.

The '32 filament has a choke in line with the positive side while the negative filament lead returns to ground via the local oscillator coil.  Plate supply to the second '34 has a pi filter arrangement in series with a 250K plate resistor. You can see the choke mounted above the socket on the rear wall.

There is a four way terminal strip on the back, left pair are marked "P" and are bridged the other pair are marked "L". Each of the L pair goes to one plate of one of the output triodes.

There are three cables coming out the back, filament supply then two others. The aerial lead heads out on one and comes back in on the other. The filament goes out on this same cable.

HT and a line from the bias resistors go out on the second cable.

There are also two wire which come in on one cable and out the other without connecting anywhere inside the chassis.


 AWA 120B circuit

Last modified Sunday March 11, 2007