This can be compensated for, however, by bringing the pitch back down to the proper frequency.

He tuned his device to the proper frequency and the screen promptly went black.

"I also told you it would be an imperfect system without the proper frequencies," Barrett said.

All she had to do was adjust the device to the proper frequency and open the channel.

"The computer has to be able to detect changes in speed quickly enough so that it generates the proper frequencies of sound."

She switched on the comm system and punched in the proper frequency.

And will you call us on the proper frequency then, please?

However, light of the proper frequency will enter and transmit through the material quite easily.

But do they have a radio telescope operating at the proper frequency?

A linear amplifier of the proper frequency is required for this job.