"Larry" wrote in message
...

Are they all going to shield the plastic instrument cases without being
forced to, too? Lots of them radiate through the cases.

Why would they? Like I told you about my multiplexers: they are in plastic
cases and they don't radiate sufficiently to interfere.
To radiate, you need an antenna. To radiate on HF, you need a large antenna.
A circuitboard of a small device is not large enough, it needs the connected
wires to radiate.

Meindert