external DSP audio filters (was Re: [RTTY] AA5AU ContestNotes for CQWW RTTY now on-line)

[Ian White, G3SEK]

Jerry Pixton wrote:
>
>Since the JPS NIR-12 filters were not available, last spring I opted 
>for the MFJ 784B Audio DSP filters which I put in series from my 
>radios, FT1000mp and IC756proII, to the sound cards. In spite of good 
>filtering in both radios, the audio filters make a BIG difference. I 
>have the audio filters set up with a 500 hz and a 250 hz position as 
>well as a twin peaked position. With the hundreds of stations on 20 
>meters last week end I could search in the 250 hz position and 
>generally seperate almost all stations. The occassional stations that 
>were sitting almost on top of each other, I just put on the bandmap and 
>moved on unless they were a multi. If they were 50 hz or so apart then 
>the twin peak filter was useful. I would say that the audio filters 
>made a big improvement in my station.
>
Do the outboard DSP filters do anything that the radios' built-in DSP 
filters and de-noisers cannot?

As far as I'm aware, the twin peak filter is the only feature mentioned 
that the MP doesn't have at all (don't know about the Pro-II) but both 
bandpass and twin-peak filtering are also available in MMTTY.

Or do the outboard DSP boxes really perform so much better than the DSP 
options in the radios and in MMTTY?


-- 
73 from Ian G3SEK