[TenTec] 250hz roofing filter

[Toshimi Horie]

Hi all. I am Toshi/JE2UFF.
My Orion which I hold narrow a roofing filter and it gose, a noise will be
stopped, 500Hz will be quaiet and it will become easy to hear it, but if
250Hz is used, a noise level will increase conversely.

In 250Hz, it becomes difficult to hear it that it is noisy and convesely.

If Orion shall be 250Hz, is it the specification which a gain increases?