Ed Price wrote:
"Remember to use hardware cloth for the screen."

In my experience, the screened room was constructed of copper insect
wire screen. All seams and joints were soldered.

As in pre-fab rooms, the room was double screened. Both sides of the
wooden studs were screened to make a copper box inside a copper box.

Every penetration was carefully screened and bypassed. The door was
shielded and had low resistance contacts all around.

We were able to accurately make very sensitive measurements in our
screened room which was sited in the center of a very high power
shortwave broadcast plant with many transmitters, usually simultaneously
operating in at least 3 bands. One band predicted as the optimum working
band for the path and, the same program simultaneously transmitted on
the next higher and next lower bands, just in case. We had several
languages and target areas at nearly all times during all 24-hour days.

Best regards, Richard Harrison, KB5WZI