[TenTec] Paragon Audio filter

[Edward A. Feustel]

> Message: 12
> Date: Thu, 27 Jun 2002 19:13:06 -0500
> From: Wm Marvin <wmarvin@mnic.net>
> To: "tentec@contesting.com" <tentec@contesting.com>
> Subject: [TenTec] Paragon II BPF Filter
> 
> Could someone tell me if the Audio Variable BPF in the Paragon II is a 4 pole or a 8 pole
> like the Corsair II?? I think the 585 Paragon has a 4 pole BPF?
> 
> 73's Bill KB9IV
> 
> 

The filter (from Figure 4-32 of the Paragon II manual) consists of
2 LM13600N Chips. each chip has two differential amplifier stages, each 
is followed by an emitter follower. So I guess it is four poles.
 From page 4-48, "The center frequency of the audio bandpass filter is 
determined by the voltage applied to R71 and R84 by the front panel BP 
control via connector 54. The center frequency range of the bandpass 
filter is approximately 220-1700 Hz and the 6 db bandwidth is always 35% 
of the center frequency. Bandpass filtered audio output from U8 is 
routed to one side of the front panel FADE control through C52 and 
connector 55.

On the upper pot board, the unfiltered (flat) audio from C43 and the 
bandpass filtered audio from C52 are combined in proportions determined 
by the setting for the front panel FADE control. Clockwise rotation of 
the control increases the filtered portion and decreases the unfiltered 
portion of audio delivered to audio amplifier U10a through connector 55, 
R91 and C57."

Ed