Re: 8 pole vs 5 pole..I knew this would happen

Posted by Geoffrey Mackenzie-Kennedy-2 on May 03, 2007; 9:16pm
URL: http://elecraft.85.s1.nabble.com/8-pole-vs-5-pole-I-knew-this-would-happen-tp446796p446816.html

I do not know where or when the term "roofing filter" first appeared, when I
first came across it in the late 1950s I was working in Canada.  I suspect
that the term originated in N.America, most probably in connection with the
type of equipment which I mentioned, most of which was purchased by Common
Carriers for use on long haul international circuits.

73,
Geoff
GM4ESD


Jack Smith wrote:

> One more data point on the term "roofing filter."
>
> I have a copy of the June 1981 RSGB Radio Communications magazine that
> reviewed Drake's TR7.
>
> It describes the design as follows:
>
>    "A low-noise, wide-dynamic range amplifier is used at 48.05 MHz to
>    precede the 10-KHz wide roofing filter."
>
>
> Leaving aside the RSGB's odd use of hyphens, it describes the filter as a
> "roofing filter" although Drake does not use the term in its technical
> manual.
>
> Is it the case that "roofing filter" is UK terminology that has made its
> way to the US side of the pond only recently?
>
>
> Jack

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