[CW] Internal BHI Noise Reduction Efficiency and Use

[D.J.J. Ring, Jr.]

I had Andy Ruggiero WD8BWW <andyit28 at gmail.com>, install the INTERNAL
BHI Noise Reduction model in my FT-897D when I had him replace the
DIGITAL DISPLAY BOARD because of tiger striping and loss of
characters.  Since Andy had my transceiver apart for the display, I
saved  on the labor costs. This is the unit.
https://www.bhi-ltd.com/images/docs/manuals/NEDSP1901-KBD_ISSA_web.pdf

This unit works on all modes, AM, FM, SSB, RTTY, CW (of course!) and
Digital modes.

I've been using it on V/UHF SSB and I cannot describe it's efficiency,
at SETTING 1, it eliminates all the background noise associated with
extremely weak signals.
By not advancing it beyond setting #1, I keep the high frequencies
which for me - a former professional radio HF operator - are
necessacaary for me to dig into the noise.
In every case, I am able to understand SSB better with the DSP on and
at #1 (lowest) setting.  When QRM (line noise) is high, I can apply
moderate noise reduction - 3 or 4 - and I can copy strong signals that
I could not copy otherwise, but what truly amazes me is setting #1. It
takes a signal I can copy 50% that has lots of noise in it, and make
it 98% copyable and removing the noise that would greatly fatigue me.

Here's Andy's recording of moderately severe QRM (static noise) on a
SSB signal, the DSP is quite aggressive at his setting, not like I was
speaking about above.
https://youtu.be/6FayKF-0754

Here's Andy's installation video of this internal unit on a FT-857D,
he goes the extra mile and encapsulates the modification in shrink
tubing.
https://youtu.be/Ek0Nd-Fq8n4

In this video Andy steps through the intensity / aggressiveness of the
DSP, initially it's at setting #4, and he steps through #5, #6 and #7
- the unit goes from #1 to #9.

Here's the unit in a Yaesu FT-817ND in CW mode, the Internal BHI DSP
is set to #7, which I also think is too much.
https://youtu.be/zBdyFbDxCuA

Andy's demo of an installation into a FT-818
https://youtu.be/wGdLDE9LI7c

Here's another fellow's installation video of the unit in the FT-817,
I'm going to skip ahead to his HF SSB test.
https://youtu.be/OwYt0gqZItw?t=1303

This fellow tests the external unit but he changes from 4 to 1 and
back off again  so you can find the difference. Andy concludes that #7
is too much DSP processing.
I mainly leave mine at #1 to #3.

I'm very happy with this, and even though I have a FT-897D which
includes DSP, the BHI unit is state of the art in 2020 so naturally
it's far superior.

I highly recommend it, and I also advise to use the minimum processing
that you need as there's less artifacts with less processing and less
removal of higher audio frequencies which surprisingly are of great
use to comprehension of on-air signals.

If I had only known that 1) Tuning to a low audio pitch, 2) use low
volume especially with headphones, and 3) use minimal digital signal
processing, I'd have been a better radio operator at sea and have less
damage of hurting my hearing.  I used to blast the audio and put the
TRIMM headphones in the hollow of my cheeks, even inverting them so
they faced upwards and outwards, using them like little speakers with
those round metal resonators TRIMM (and others) used with magnets with
windings that modulated those metal disks.  Ouch!

73
DR
N1EA