bhi NES10-2 DSP Speaker Review
Stephen Newlyn VK5VKA, the writer of this article has had an Amateur Radio Licence since 1991 and has been Shortwave Listening for about 30 Years. For a number of years he was Chief Editor for "DX Post" of the now closed Shortwave listening "Southern Cross DX Club", and has written articles for "CB Action" and "Two Way" magazine during the 1980's.
Photo courtesy of bhi Limited, United Kingdom
Introduction
Since the
demise of VNG (Australia's HF Time Signal Service)
I have been trying to work out a way to receive time signal
station WWVH from Hawaii on 15 Mhz with a clearer signal
during the Australian daytime. Most days WWVH starts to fade
into South Australia around 0300utc but the signal
is noisy from natural noise as well as some local electrical
interference.
Then I saw a review of the bhi http://www.bhi-ltd.co.uk/ NES10-2 DSP speaker in
the UK publication "Shortwave Magazine"
September 2002 edition which gave the product a good review and
then finally I saw a review in the Australian publication
"Radio and Communications" March 2003 edition.
I've heard about DSP on high end receivers and transceivers but
because of the cost I was not prepared to buy one
of those (well at least not until the DRM receiving mode is
provided for, but that's another story!). Well; I decided
to buy a NES10-2 speaker and spent $AU339 (including postage
within Australia) from the official dealer, Andrews
Communications in Sydney. They can be found on the Internet at (http://www.andrewscom.com.au/).
Incidentally Lee of Andrews
Communications is very responsive to emails and treats his
customers as he would liked to be treated himself if he was
buying a product from someone.
The speaker arrived double boxed so there was very little chance
of damage during transit from Andrews and it was
sent registered post.
The United Kingdom manufactured bhi NES10-2 is small in size,
coloured black, rectangular in shape and it's size
is W110 x H65 x D55 mm. The front is dominated by the speaker
grille with the model number on the bottom left corner
of the unit and a LED indicator on the top right. On the top of
the unit there is a "Sensitivity Control"
and a "On/Off Noise Cancellation" switch.
On the rear of the unit are "Dip Switches", a printed "Noise
Cancellation Selection Table",
"Audio Input Lead" and a "DC Power 2.1mm socket".
On the left side of the speaker is a "Headphone" socket. On both
sides of the unit you have support for
the supplied and fitted "Mounting Bracket".
Accessories supplied (for the Australian Market) include a
Mounting Bracket, 2 Fixing Screws, 4 Small Self Adhesive
Feet, 24 Page Operating Manual and a 2m DC Power cable.
Setting
Up
After a good look at the manual, which is well written (Yes! I
am one of those who reads the manual first!). I
proceeded to hook up the unit to DC power, unfortunately due to
how my radio shack is laid out the DC supply was
3 metres away so I had to make my own cable, as the supplied
cable was 2 metres long.
I then connected the supplied 2 metre long speaker cable to the
test receiver (in my case a Drake R8A Communications
Receiver which needed a 6.5mm adaptor as the supplied cable uses
a 3.5mm plug).
Operation
There is no actual on/off power switch for the speaker, so you
just turn on any 12-28 volt dc power supply to operate
the unit.
As power is turned on the LED light glows. The LED indicates
which position the "On/Off Noise Cancellation"
switch is set. If the LED is glowing red it indicates that DSP
function is off and if it's coloured green it indicates
the DSP function is on. If you are colour blind though the
intensity of the LED changes with mode so you can easily
see the mode change.
There are two controls which once set rarely need to be adjusted
(unless of course you change the connected receiving
equipment or encounter a signal that needs extra processing).
They are the "Sensitivity Control" and
the "Dip Switches".
The "Dip Switches" by default are already set to Level 6, this
setting appears to be well thought out
as I found pretty much that this is the optimum setting for
general use. However you may find a lower or higher
setting may be more suited to your situation.
The operating manual says that the "Sensitivity Control" is set
at first, by turning it fully anti-clockwise
and then turning it back a quarter of a turn." Further
adjustment may be necessary but most modern equipment
will accept the settings mentioned in the manual. By the way the
"Sensitivity Control" is designed so
that it cannot be easily changed (accidentally bumped etc.).
Well the next thing to do is to switch "On/Off Noise
Cancellation" off and then find a signal which has
a bit of noise. Then switch on the "On/Off Noise Cancellation"
switch. It may take a couple of seconds
for the DSP to work when you will notice a distinct improvement
in audio quality with less noise and in most cases
a much more listenable signal.
I've tried it on all types of signals including AM Shortwave
Broadcast, Long Wave Beacons, SSB and Morse Code signals.
Audio quality is improved substantially. The speaker may be
small but the audio output is more than adequate for
most situations.
On some signals there is a "Robotic" sound on some voice type
signals but actual clarity is better than
listening to the noisier unprocessed signal.
Leaving the "On/Off Noise Cancellation" switch on sometimes make
you wonder whether the radio is actually
working because it makes background noise almost disappear as
the usual crackle and pop is virtually gone.
Conclusion
Some products when released, arrive with a lot of hype and
fanfare and turn out to be not as expected; however
in regard to the bhi NES10-2 speaker I believe that this is not
the case. I would thoroughly recommend this product
to any one wanting to improve their reception of radio signals
without spending a huge amount of money on a new
DSP based receiver or transceiver.
Notes
This product was bought outright by the reviewer and was not a
free review unit. The unit was not tested with any
test equipment apart from my ears and comparing signals. For USA
based readers this product is sold as the GAP
HEAR-IT. A review written by Bob Grove was featured in the May
2003 edition of "Monitoring Times". For
more information please check the GAP web site at http://www.gapantenna.com/.
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