John Smith wrote:
Somewhere, I read that the black plastic and grey conduit types were
unsuitable for antenna construction.
And, if I remember correctly, it was (claimed) due to carbon in the black
and metal oxide coloring in the grey...

Was this an old wives-tale?

Regards,
John


It is correct , normally testing the conduit in a microwave for 30
seconds works , if its not hot then its reasonably rf resistant .