Not too long ago I purchased a replacement filter for my NRD545
from Sherwood Engineering Inc. This filter is 6 kHz wide and
is suppose to reduce the splatter that the NRD545 suffers. The
filter is installed on the CDA-752 board. The installation
project can be performed by the NRD545 owner, but the original
filter is installed very well and removing it is a chore and a half.
When I informed the Yahoo NRD545 Group about this upgrade on my
NRD545, I was smothered with negative comments saying that the
filter didn't help the NRD545 at all. Well, being "thick skinned"
I didn't let the negative comments influence me. I have since
proven to myself at least, that the replacement filter really
does help reduce (not eliminate) splatter.
You'll find three sound bites below. Each is about 30 seconds
in length. The first (1) sound bite is of the VOA on 9720 kHz
transmitted from the Philippines. You'll notice there's no
signal heard because the splatter from 9715 kHz covers VOA's
signal which is a person speaking in Indonesian. This is using
the stock filter for the NRD545.
The second (2) sound bite is on the same frequency a couple of
minutes later and is still the VOA's transmission from the
Philippines of a person speaking Indonesian. Although there's
still splatter, you can hear VOA's signal. This sound bite is
while using the replacement filter from Sherwood Engineering.
Finally, the third (3) sound bite is Radio Nederland's broadcast
on 9715 kHz. He's the guy who produced the splatter that blocked
9720 KHz.
I installed both of the filters (stock and replacement) on a piece
of construction board I purchased at Radio Shack with switches
also purchased at Radio Shack, That allowed me to to switch between
the two filters quickly.
Click here for the Stock Filter that
came with the NRD545, sound file of 9720 KHz.
Click here for the Replacement Filter
from Sherwood Engineering Inc. sound file of 9720 KHz.
Click here to hear Radio Nederland on
9715 KHz, the guy who was causing the splatter to 9720 KHz.
Although this isn't a really a scientific test, it showed me that I
had gotten the results that I had hoped for when I purchased the
filter.