philips: Philips BD284u. Loud hum.

When switching on I get a loud hum on all bands. I have replaced many capacitors and all the tubes but there is no change. Wattage use on warmed radio is 33 watts. 

My schematic shows standard European voltage 220 volts. I assume the voltages listed on the schematic relate to the 220 volts. As I live in the USA the line voltage is 120 volts so my measured voltages are lower. 

As I am very new at this, especially German radios, I am having trouble identifying some components. Is there a component identification sheet available for 1950's and 1960's German radios?

Thank you for any and all help that can be provided. Phillip Yannone.

To thank the Author because you find the post helpful or well done.

Philipp,

First of all I have some questions.

Do you know that your radio is not isolated from mains and you’re aware about the danger.
Are you using an isolating transformer or a variac when working on the set?

Do you have exactly this model or the export variant labeled with the suffixes -46, -47, -48, -49 ?

Which capacitors have already been changed?  What about the electrolytic filter capacitors?
Do you have an underneath picture, maybe before and after changes?

What kind of measuring device (multimeter) do you have?

Generally it is not a good idea changing capacitors indifferently.

 

Regards, Marc

To thank the Author because you find the post helpful or well done.

Thank you Marc for your reply, The model is BD 284U no suffix (Philetta 284 de luxe). I'm aware it has a hot chassis and when working on it plugged in its through an isolation transformer. All electrolyics are replaced. All replaced caps tested Leakey at low voltage. My test meter is a Fluke 21.

I have to say that since the post the problem is resolved. It was a broken ground on the uabc80. That has a rubber mounted base. Since the repair the radio is working quite well. There is slight station drift between cold radio and warmed up.

To thank the Author because you find the post helpful or well done.