Filter setting

[Chris Kimball]

I'm having confusion about setting the receive filters.  

I'd like to have a 1 kHz wide filter at 1 kHz, that is, with a passband from 500 to 1500 Hz. My rig has a 1 kHz wide roofing filter.  In CW mode I can manipulate the bandwidth/center frequency controls so that the bandwidth is 1000 Hz and the center frequency is 1000 Hz, and the roofing filter is 1000 Hz.  When I switch to the data mode, however, the lowest center frequency I can obtain is 1.1 kHz.  The roofing filter is still 1000 Hz.  Even when I reduce the bandwidth, I can't push it lower.

Must be something obvious!

[Joe Subich, W4TV-4]

 > When I switch to the data mode, however, the lowest center frequency I
 > can obtain is 1.1 kHz.

Which data sub-mode?  In DATA A, although I do not have a 1 KHz IF
filter, I can run the center frequency all the way down to 400 Hz if
I want (not that a center frequency that low is particularly useful).

73,

    ... Joe, W4TV


On 8/25/2016 2:30 PM, Chris Kimball wrote:

> I'm having confusion about setting the receive filters.
>
> I'd like to have a 1 kHz wide filter at 1 kHz, that is, with a passband from
> 500 to 1500 Hz. My rig has a 1 kHz wide roofing filter.  In CW mode I can
> manipulate the bandwidth/center frequency controls so that the bandwidth is
> 1000 Hz and the center frequency is 1000 Hz, and the roofing filter is 1000
> Hz.  When I switch to the data mode, however, the lowest center frequency I
> can obtain is 1.1 kHz.  The roofing filter is still 1000 Hz.  Even when I
> reduce the bandwidth, I can't push it lower.
>
> Must be something obvious!
>
>
>
>
>
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/Filter-setting-tp7621800.html
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[Chris Kimball]

Dear Joe,

Thanks!

I'll bet the DATA X mode is band specific!

I had carefully set DATA A on 80m and on 80m I can set the center
frequency as I'd like it.  That's where I usually operate in the data mode.

Today, I was on 40m, where I don't normally work data.  I'll bet I
haven't set DATA A for 40m.

Could that be it? I'll give it a try.

Best wishes,

Chris

[Chris Kimball]

Dear Joe,

That (the data mode) was it!  Once I set the data mode to DATA A on 40m
I could do what I wanted.

I have lots to learn here!

Thanks for you quick and on-the-spot reply!

Best wishes,

Chris

NQ8Z