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Re: [TenTec] PBT and other issues.

To: "'Discussion of Ten-Tec Equipment'" <tentec@contesting.com>
Subject: Re: [TenTec] PBT and other issues.
From: "Rick - DJ0IP / NJ0IP" <Rick@DJ0IP.de>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Wed, 29 Oct 2014 17:26:15 +0100
List-post: <tentec@contesting.com">mailto:tentec@contesting.com>
Yes, and we can also add in insertion loss as another factor.

As for the Elecraft K2 filter, well we don't want to criticize it too much;
after all, they did copy Ten-Tec's patented Jones Filter for that radio.
;-)

73 - Rick, DJ0IP
(Nr. Frankfurt am Main)


-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Jim Brown
Sent: Wednesday, October 29, 2014 5:03 PM
To: tentec@contesting.com
Subject: Re: [TenTec] PBT and other issues.

On 10/29/2014 8:24 AM, Rick - DJ0IP / NJ0IP wrote:
> Although we speak of filters as being 2.4 kHz or 500 Hz bandwidth, that is
only a small part of the story.
> The bandwidth we state here is the "6dB bandwidth".  Perhaps more
important is the "60dB bandwidth".

Also important is the amplitude and phase response WITHIN the passband. 
Poor design can produce poor phase response, which degrades speech
intelligibility. This was a major shortcoming of the Elecraft K2 -- it
sounded fine listening through the full bandwidth TX filter, but when the
multipole CW filter was realigned for narrow SSB it was hard to listen to.

73, Jim K9YC

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