[TenTec] vague answer to the triton audio filter question

Mike Hyder -N4NT- Mike_N4NT at charter.net
Mon Jul 26 14:47:01 PDT 2010


I believe when the 544 is switched to CW one stage of the filter is active. 
The second CW position uses all stages.  The 544 AGC voltage is derived from 
audio.  The Ten-Tec filter appears in the audio string before the AGC 
sampling point.  So to be properly effective, an added audio filter needs to 
be put into the audio circuitry before the AGC sampling.  If this is not 
done, then signals outside the passband of the filter can still pump up the 
AGC voltage.

73, Mike N4NT

----- Original Message ----- 
From: "geoffrey mendelson" <geoffreymendelson at gmail.com>
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Sent: Monday, July 26, 2010 2:57 PM
Subject: [TenTec] vague answer to the triton audio filter question


>I was looking through a book I bought about 15 years ago that was a
> compilation of QST reviews called "The Arrl Radio Buyer's Sourcebook".
> In it is a copy of the review for the 544. There really was not much
> to say about it, and the review as published in the book, had a full
> schematic of the audio filter and a discussion of components used to
> build it.
>
> If you have access to the QST review, it would pay to read it. If the
> review is different than the one in the book, let me know and I can
> send you a copy.
>
> BTW, it was a simple 4 stage active audio filter, using IC's common 20
> years ago. Almost anything similar would do. For example I used to
> have an MFJ 9020 QRP transceiver with a plug in audio filter. If you
> can get one from MFJ, it would be IMHO a suitable replacement.
>
> The TenTec filter had 4 bandwiths, the MFJ has one, but the 544 only
> used the last, i.e. all four cascaded.
>
> Geoff.
> -- 
> Geoffrey S. Mendelson,  N3OWJ/4X1GM
> To help restaurants, as part of the "stimulus package", everyone must
> order dessert. As part of the socialized health plan, you are
> forbidden to eat it. :-)
>
>
>
>
>
>
>
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