|Them what was tested.|
check your PVC easily with the microwave test. Put a sample of the pvc
on a paper towel in the microwave oven. Put a cup of water in there
next to it. (no metal trim on cup, plain china).
Set the microwave to 3 or 4 minutes. When you see the water is boiling,
stop the oven. Carefully test the pvc with a wet finger tip, to see if
it got warm, ie warmer than the hot air around the cup.
If not, it is good for HF for sure. This is based on a formula for
dielectric loss that shows such loss is directly proportional to
frequency, the higher the test frequency, the higher the loss would be
for a given material. Thus, no heating at microwaves means it is
a good insulator at HF.