Hello all,
I have a Bruel and Kjaer 2204 that I repaired. When I first purchased the unit, it had a nasty bleed-in (~2.5kHz, same as the voltage generator) coming from what I can only suspect to be one of the output amps. Replacing all of the polarized caps unfortunately did not fix the issue. I disconnected the REF signal wire to make sure it was not causing the noise. No change was seen.
Adjusting the output attenuator quickly leads to a gain in the noise, thus why I suspect that it is coming from the amplifier.
The input attenuator dial does not change the noise's amplitude. The noise is the same as the noise produced by the transformer and the power signals prior to rectification to DC.
Please, your advice on the matter is appreciated.
Respectfully,
I have a Bruel and Kjaer 2204 that I repaired. When I first purchased the unit, it had a nasty bleed-in (~2.5kHz, same as the voltage generator) coming from what I can only suspect to be one of the output amps. Replacing all of the polarized caps unfortunately did not fix the issue. I disconnected the REF signal wire to make sure it was not causing the noise. No change was seen.
Adjusting the output attenuator quickly leads to a gain in the noise, thus why I suspect that it is coming from the amplifier.
The input attenuator dial does not change the noise's amplitude. The noise is the same as the noise produced by the transformer and the power signals prior to rectification to DC.
Please, your advice on the matter is appreciated.
Respectfully,