I'm sorry, I search everywhere and could not find a good answer for this.

Is turning on you receivers noise reduction a good or bad idea for digital modes?

Is it smart enough to know not to filter our the digital transmissions?

I've been wondering this for a long time and can't find a decent answer.


Rig is Kenwood TS-590 is that makes any difference.

My understanding is that you want it (noise reduction, notch filters, etc) off, and that is how I do it.

I always turn off all DSP, noise reduction, attenuator, preamp, etc. when working digital modes.

I turn off all filtering and noise reduction. Once I'm on frequency I turn my volume off. There is an occasional noise I pickup that can be removed my running the noise blanker.  I still haven't figured the source of the noise.
But, the running waterfall is a great visualization of what your filtering, IF shift, etc can do.

I leave the preamp on but everything else is off for digi.

Putzed around on 20m PSK one day turning on and off the various signal conditioning tweaks. None of them helped except preamp. In some cases signals went away completely. In other cases signals became too distorted to decode.

One trick I do when pulling in a weak signal that won't decode is to narrow the bandwidth using the DSP Hi/Shift Lo/Width then tweak the VFO to put that signal into the narrower bandwidth. Sometimes the background noise gets to be a bit heavy doing this so my first shot is to turn the RF gain down. Tweak carefully where you lose the noise but not the signal. Sometimes just turning off the preamp will do the job also. Works great on PSK and RTTY. No so much on JT65.

DSP Hi/Shift Lo/Width and RF gain is found on Section H, Page 6 of the TS-590 owners manual. It's what I have sitting in the shack.

Oh, one more tip. Some lid tuning up in the PSK or RTTY band? Or a really obnoxious PSK signal wiping out the band? Turn on the notch filter (Notch (Wide) on the TS-590) then place the notch on the offending goofball. Watch your signals magically come to life.

Me too.  I also usually turn down RF gain a bit to clean up the waterfall a bit.

Same here, turn off NR, NB (Noise Blanker), and use the automatic notch filter (ANF) to kill offending signals.

DSP interprets digital as noise.

I've done this with some success running PSK , and JT. When theres 3 of us all within 20 miles or so of each other on 20m digital working DX some signals are going to be a bit loud.
My IC-7000 has dual notch filters. Fun is when you park on a freq and notch out either side and just go. Just remember to leave a bit of an opening on both sides for the people that drift.
Spotting for each other and chatting on 2m simplex does come in handy though.

yep. turn all the DSP NR stuff off.

set the 590 to DATA

I set IF filter A to wide
and IF filter B to narrow, about 250hz ( less if the band is crowed )

I hunt on wide, and work them on narrow

I use DM-780 to center what I'm working, in the middle of my bandpass

the filtering on the 590 is fantastic

Thanks for all the tips.  I've been leaving them off, it just so noisy in my area was wondering if it would help.

Wow, I never even seen or used the DATA button.  Sorry I'm new and still learning this rig.

I need to find a local expert on the 590 to give me a proper walk through.

Try turning the AGC off and ATT on, then adjusting the levels in the software until your waterfall is just barely speckeled.



 

Preamp off, AGC off, noise reduction off, and IF filter narrowed out so only 100 hz is in the receiver's passband.

Hit the DATA button

Now you have 2 selectable bandwidths

select them by toggling the IL FIL button.

you can adjust there width with the WIDTH knob

use a wide filter to see the entire waterfall....and the narrow to reject everything except when you want to receive


what software are you using for digital ?

Ham Radio Deluxe/Digital Master 5

I don't understand the narrow instruction, when I narrow it, it makes data too wide to be decoded?

Also how do you make DM-780 center what you are working on.

What should SFT be set too?

Thanks

here's a quick screenshot of PSK31

note how I switched from the wide IF filter, to the narrow....if the band was crowded, this would reject all the other signals.  ( I should have taken a screenshot of a crowded band like 20m )

circled is the "CENTER" button.

click on a signal on the waterfall, then hit CENTER....it will automatically adjust your radios VFO so that signal is right at 1500hz***, the center of your bandwidth filters....how narrow you want IF FILTER B depends on.....the width of your signal, and how crowded your waterfall is.

the 590 can narrow it all the way to 50hz which is way too narrow for RTTY, but might be just what you need for CW.


*** under DM780 options, select "enable center frequency marker" and for RTTY, PSK, etc, I choose 1500hz.
( for CW, I select 800hz)



with this setup, you can quickly hunt stations.
either with DM780's buttons, or the IF FIL button on the 590, select the wide one, find a station, hit CENTER, if the band is crowded, hit the other IF FIL, which you might have a 250hz wide,

because your narrow filter has rejected out all the other signals/noise on the band, you'll decode him better.

work him

go wide

hunt
work another.

repeat..... until beer is empty or DXCC is achieved

where is that ?

on the 590 or the software ???

on the 590, it on the inner knob of the Width selection.

Probably I.F. shift, you normally want this centered. There should be a detent on the knob. Don't forget about filters, they have both a band-width and a center-frequency. 73, Rob

when the radio is set to DATA, that is your center freq,....like DM-780, set it to 1500hz. for data

the outer knob is the bandwidth, which you can set for IF FILTER A and B

notice when you play with these knobs, the bandwidth bar on the signal meter varies, narrow to wide.



with DATA off, like when you're talking, you can adjust your low and high bandwidth, all of this can been seen on the radios meter, and the DM780 waterfall.....notice in my pic posted above, how I made the waterfall narrow

The TS-590 allows you to have a separate menu profile. This is a user selectable Menu "A" or Menu "B" profile.

In other words you set up one profile for SSB and the other profile for Digital.  



This way all of your menu setting are saved per mode of operation. It is a extremely handy feature and will save you tons of aggravation.

The separate profiles allow you to save optimized menu parameters without having to change menus settings each time change modes.

G3NRW is the "go to" place for everything Kenwood TS-590.

G3NRW Homepage Kenwood TS-590

Here is his helpful tutorial on how to set up your Kenwood for digital. Its a "hand holding" step by step tutorial. Do yourself a favor and read this.

G3NRW Digital Tutorial

Thanks again for all the help, this definitely is the best HAM forum on the internets.

I didn't have the center marker activated.  Makes more sense now.