External DSP filtering for Mobile HF

[w5mtb]

I'm running a FT-857D/ATAS-120 mobile setup, External ICOM speaker. I've also RF grounded & reduced vehicle-produced QRN per K0BG's page. The setup has been great for working DX, in it's stock arrangement, but I'd like to know if anyone else out there has deployed any external DSP filtering on their mobile & if it would make a significant enough improvement to justify the external DSP. I'm looking specifically at bhi-ltd's noise cancelling inline modules, or possibly exchanging the ICOM speaker for one of their DSP speakers. Any information or advice appreciated.
73,
W5MTB -John

 

[JnglMassiv]

Have you gone through determining whether the noise is related to the installation in the mobile?
And does the DSP already installed in the 857D make a significant improvement when enabled?

I have the bhi upgrade installed in my similar 817ND and it is like night & day. I can't recommend it highly enough. However, this is in a fixed location and not sure how relevant it would be mobile.

 

[w5mtb]

No problem with localized noise, related to the mobile. Unless the band is noisy, I usually see S1~2 noise or less. This is usually in rural countryside driving. I would use the device when traveling into urban areas, where noise can increase to S6~8, depending on the source. Traffic signals tend to be especially bad, due to wireless traffic control/camera back-haul, etc. Seems there's more dirty 802.(x) stuff out there than before. I'm usually in transit when working QSO's & at times, getting a partial completed QSO due to ORN, having to re-establish to complete. Just looking into the additional DSP filtering to possibly alleviate the problem. (logging QSO's via Voice Recognition-software)
-I guess you'd say, I'm looking for additional DSP, as I'd prefer to have the ability to enable/disable on-the-fly, rather than switching through the menus to modify settings..

 

[acyddrop]

Spent a day and some extra bonding everything in the Range Rover, plus additional bonding to the antenna mount for the Scorpion/IC-7000 setup. I also went through and handled additional vehicle noise. I have no real local noise issues any more. Was time well spent. Unrelated to noise or anything I also hacked the IC-7000 into the vehicle nav screen for a larger display when I don't need sat nav or my wife isn't playing around with it, which is one of the most useful things in my mobile setup now.

 

[LtDoc]

In a 'nut shell', a little bit of DSP goes a long way. It can 'help' with noise, and if it's not needed it won't make a lot of difference. It won't do 'miracles' and clean up a really noisy situation, but it can help.
Once upon a time, Radio Shack made a DSP filter that did very well. It wasn't 'exceptional' by any means, but it worked. The problem with any DSP filter -now-, is that people expect too much form them. An audio type DSP filter will help. An 'IF-stage' DSP filter will help even more, but it still won't do 'miracles'. You can never get rid of noise completely, you just have to ignore it...
- 'Doc

 

[nanZor]

I guess you'd say, I'm looking for additional DSP, as I'd prefer to have the ability to enable/disable on-the-fly, rather than switching through the menus to modify settings..

I know it's kind of a pain, but while you are evaluating external units, you don't really have to go through many menus to get to the DSP noise-reduction, notch-filter, or bandpass filter.

Just tap the top 3rd DSP button. Now select either:

A) DNR - (Dsp Noise Reduction)
B) DNF - (Dsp Notch Filter)
C) DBF - (Dsp Bandpass Filter)

Note that all the 857/897's I've seen come out of the box with DBF disabled! You'll want to make sure that is set on, and the high and lowpass set accordingly - at least initially. I've seen complaints that the 857 is "hissy" and noted that the dbf isn't turned on or set to something high like 5K. I always run with DBF turned on.

I also personally like running with
CAR LSB R = +250
CAR USB R = -250

Although suit to taste, but out of the box they are set at zero, and seem somewhat shrill unless adjusted a little bit.

Perhaps this will help make things a bit more tolerable until you get an external unit.