[TenTec] 3.1 KHz IF Filter for 2nd IF in Omni 6

[Mark S. Holden]

On 1/9/2016 11:27 PM, Gary J FollettDukes HiFi wrote:
> As I recall, when one purchased the Inroad “wide” SSB filter for the first IF, one needed to adjust the BFO frequencies in order to get proper positioning of the carrier on the filter slope. I do not (yet) know the adjustment range for the BFO’s bu I am guessing that the BFO adjustments in this one must have pushed that frequency another 300 Hz, or the BFO crystal(s) were changed out.
>
> Anyone who had spent $1000 to have custom filters made up would certainly have taken proper measures to ensure that transmitted SSB was properly generated.
>
> I should know the answer tomorrow.
>
> I have not looked yet, but it is POSSIBLE that the radio may have been rewired to route the TX 9 mHz IF signal through the position 2 filter. That is a lot easier to do the one might think, due to the use of diode switching to select the desired filter, so it is possible.
>
> The first IF filter that was in the position 2 is marked “48074” and the second IF filter in position 2 is marked 48058.
>
> Can anyone tell me if these are the numbers for the “stock” SSB filters?
>
> I can measure them fairly easily for bandpass but it would save some time if anyone simply knew the answer to that.
>
> I will, however, put a frequency counter on the BFO tomorrow and measure the frequencies on LSB and USB to determine what was done to make this work. As you know, without adjustment of the BFO down the filter edge, both carrier suppression and SSB suppression would suffer quite a lot.
>
> Gary

Those numbers were stock codes used for 2.4khz filters.  If they are 3.1 
perhaps they modified factory filters.

<http://www.tentecwiki.org/doku.php?id=filters>