[davidgem1406]

Yesterday I was using my Black Star counter along with a signal generator to check the FM calibration on a Goodmans One Ten tuner/amplifier.

I was using the counter to set the generator frequency, whilst the generator was connected to the aerial input of the tuner.
Also, an AVO meter was connected to a test point in the tuner ( the only meter I had that would do 50uV)

I had a problem with the counter in that it produced a huge amount of radiation that drowned out the oscillator signal.
This radiation/interference was being created by the by the gate frequency, varying the gate frequency would vary the interference, most of which was being picked up by the connecting leads of the AVO meter.
Removing the AVO did not cure the interference, but it reduced to a far lesser level.

I remember, from a long time ago, that I had opened the case to the counter and found it was an all plastic construction without any internal screening.

If possible I would like to add some screening. Using conductive paint or metal foil to coat the inside of the cabinet and grounding it comes to mind.

Has anybody experienced this problem?
Or are there any other ideas as to how this counter can be screened to reduce the radiation it puts out.

I would mention it is not an AC supply driven unit so there is no external grounding available. It uses either batteries or an external DC supply. In this case, it was the external DC supply.

Best regards
Dave