Bush DAC90

   

BUSH DAC90. This popular AC/DC Mains valve radio was made in 1946, and employs l.w & m.w bands. The valve line-up is :- CCH35, EF39, EBC33, CL31, CY31.
It looks similar to the later DAC90A of 1950, but there are many differences between the two models, so you could say that they were vastly different sets altogether.
The DAC90 first I.F. Transformer core sometimes comes apart from it's former, thus requiring repairing. If the damage is not too bad, the ferrite core can be repaired with "superglue". This symptom can always be recognised, as one can always hear the "clattering" of loose material in the set, and the odd fact of the stations being received when the set is turned upside down, only.
My set also suffered the fault of the CL33 valve cathode resistor changing value when the set was switched on, and yet when the set was "cold", it reverted back to it's normal value. Replace this component.
The loudspeaker also requires attention, as the fabric holding the cone to the frame becomes loose, due to deterioration of the original adhesive. Apply adhesive like "evo-stik" to the area where the fabric of the cone meets the frame. You will have to undo many nuts & bolts to remove the speaker, which is fastened to the chassis, so patience is required, as the bolts were originally coated with some solution to seal them.
For safety's sake, change the old single pole mains switch to a double pole type. Watch the ballast resistor, it gets very hot, and can also burn out the card back, thus exposing the resistor to the user, making the set a possible danger hazard (shock or burn).