Grundig 1070

Hi, trying to get my grundig 1070 up and running. Tubes are lit up and test ok. It is making a loud hum and not receiving, any suggestions on how to proceed?

A

The loud hum is being caused by open electrolytics. With those open, the radio won't even think of playing, as most of the voltage is ac, due to open filter.

Replace the electrolytics, and, it should help alot.
Bill Cahill

Hi Bill, I have a bad ECC85. The unit checks out on a bulb limiter, no shorts. Still think it could also be caps? Getting the chassis out any tip so I don't screw up the channel finder

thanks A

I think you'd better ask some of the other guys. I haven't touched a German radio in years, and, honestly, I think they are a nightmare to work on.
Bill Cahill

look at the componets if it looks like that the electrolytics are original to the set, replace them, after all they are 50 or so years old and you dont want to go to the trouble of changing them a few years down the line.As to chassis removal look carefully as to how chassis is removed you may have to remove something so the top of the chassis will clear without snagging the dial string. caution---some of the older Grundigs used glass for the dial, later ones used plastic. go SLOW and remove chassis slowly. you may do better to have a second person assist in removel. Good luck in your attempt. Norman

I have done a couple of Grundigs and the basic electrical side like replacing caps was not too bad - its more the mechanical stuff that can be a real challenge. The wiring is thinner than American sets and it threads around a lot so it takes some getting used to. You often have to use a continuity tester because you cannot see where a wire ends up.

I have not seen the schematic for this set so YMMV but there are typically 2 50 UF 450V caps in a big single can, which can be replaced by 2 individual electrolytics with the negative ends joined together, going back to ground. I mounted them on the base of the old capacitor can or you could put a little terminal strip in there. Make sure that you keep the negative leads as short as possible so that you do not get a residual hum. These things have virtually zero hum when they are right. Take plenty of photos and notes as you go along and it is not too intimidating