[Elecraft] [K3] Roofing filters are misunderstood

[Jerome Sodus]

Thank-you, Greg.

Excellent.

Jerry KM3K

 

  _____  

From: Greg [mailto:ab7r at cablespeed.com] 
Sent: Monday, May 12, 2014 12:52 PM
To: Jack Brindle
Cc: Jerome Sodus; elecraft at mailman.qth.net
Subject: Re: [Elecraft] [K3] Roofing filters are misunderstood

 

http://www.elecraft.com/K3/Roofing_Filters.htm

 



 

On Mon, May 12, 2014 at 9:45 AM, Jack Brindle <jackbrindle at me.com> wrote:

Jerry,

Why do you say it has been corrupted? This is exactly the purpose for the
Roofing Filters in the K3.

Jack B, W6FB


On May 12, 2014, at 9:33 AM, Jerome Sodus <jsodus at comcast.net> wrote:

> Hello Bill,
> The term "roofing-filter" made sense back in the 1980's when I designed
> roofing-filters at 70 MHz.
> Bandwidths would be in tens of KHz.
> The purpose then was to protect downstream circuitry by rejecting very
> strong out-of-band signals that could cause overload; selectivity was not
> the purpose.
> Selectivity was done further downstream.
> So the term has become corrupted over the years.
> 73 Jerry KM3K