"Cecil Moore" wrote in message
news
Roy Lewallen wrote:
The only way to prevent this is to completely shield
the dummy load and transition to the feedline, and have no seams, holes,
or cracks which could let any current get from the inside to the
outside.

A good example of such a dummy load is the Bird Termaline
Coaxial Resistor. I've got model 8020.
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All the above, N connectors and double shield coax. RG8X types seem to be
the worst for radiation, although it does have other redeeming features. I
take it you have RF in the shack even on the dummy? Don't forget about
other RF paths like the audio shields and data lines. Regular 95% shielded
coax is said to have isolation of about 60 dB (RG8, 58c) maybe as much as 90
dB for double shielded. Unless there is some bump in the line that causes
the shield to radiate. There will be resonances in the entire line that
cause points of high voltage and high current.