VHF noise when battery charging

[transmitterdan]

Originally Posted by DavidSaunders

Excuse my ignorance here BocaIII,
What are ferrites? Where can "good ones" be found?

There are two types of ferrites made by a company called fair-rite that are applicable to VHF noise suppression. One is so-called type 43 and the other is type 31.

31 Material Data Sheet - Fair Rite

43 Material Data Sheet - Fair Rite

They supply these materials in various shapes for different applications. A common type is a snap-on design that consists of 2 halves that snap together over a piece of wire.

Round Cable Snap-Its Archives - Fair Rite

When the halves are snapped together it tends to prevent the flow of current at VHF frequencies thus suppressing noise. It takes some experience to apply these in the correct location and around the correct wires.

Typically these will not help if the noise is not RF. For example, 60 or 50Hz buzzing will not be much affected by these ferrites. For that you need something with a different mix of iron.

[continuouswave]

Originally Posted by Cadence

I think you are assuming they have a genset.

I had to infer that there were two sources of 120-VAC because YOU said the problem only occurred when on shore power. I read that as YOU were assuming the problem with the 120-VAC operated battery charger did NOT occur when the 120-VAC operated battery charger was running from a source other than shore power.

If you meant to say that the battery charger only caused interference when the battery charger was operating, you should have said that, instead of saying it only caused interference when operating from shore power.

Yes, I agree, that a battery charger is unlikely to cause interference when it is not being operated. That premise is quite reasonable to accept.

Originally Posted by Cadence

A bad diode in a charger can allow it to work at a noisy half wave.

Yes, but I still don't follow you line of thinking that a malfunction in the charger or some intrinsic element of a properly worked charger could only cause interference at a non-radio frequency.