[TenTec] Looking backward?

[Clark Savage Turner]

The roofing filter mod does not give up any modes at all.  It is a 
simple 4 pole filter switched in/out of the line according to the NAR 
filter switch positions.

But the point is well taken, the original roofing filter was wide and 
the close-in dynamic range for CW and SSB suffered.  I like to think of 
this mod as a "correction" for the narrower bandwidth modes, which 
adjusts for what used to be a "compromise" for all modes (widest 
bandwidth mode had to be accomodated.)

I have the mod in my OMNI VI and it is simple and appears to give me a 
significant advantage (I can hear it clearly) and increases my "fun" 
and "interest" factors.  I am very willing to spend $150 - $200 on 
something that teaches me a whole lot more about my rig's IF chain and 
how it works.  Then again, I also enjoy the "bragging rights" I get 
when I sit down with my friends who have the FT-1000D or ICOM 7800.  I 
believe the FT-1000MP can take advantage of a similar roofing filter 
mod and may approach this performance (though the filters are at a much 
higher IF frequency, so the results may not be so dramatic and may only 
be at SSB bandwidths).

Anyway, its fun to be an amateur radio operator and have this 
discussion.

Clark
WA3JPG

On Jan 12, 2005, at 1:54 PM, NJ0IP wrote:

> Installing the INRAD roofing filter is a compromise, not just an
> improvement.
> You are giving up two modes (AM & FM) so that other modes (e.g., SSB, 
> CW,
> digital) will be improved.  Ten-Tec could have installed a narrower 
> filter
> by design, but my guess is that the bulk of the people then and still 
> today
> prefer to have two extra modes at the cost of some performance.
>