Yaesu FT-817 Instruction

bhi

NEDSP1061 Noise Reduction Module

Yaesu FT-817 Version

Fitting Instructions

Sound Engineering Solutions

bhi

1061-104D

Issue C

Page 1

1. Introduction.

The bhi NEDSP1061 noise reduction module is a fully integral solution for noise
reduction on the Yaesu FT-817.

Features:

n 4 Levels of noise cancellation (up to 35dB)
n Single Button operation
n Visual and audible indication of operation
n Low power consumption
n Retains the internal battery pack
n Fully integral installation
n Stores the last used filter level.
n Automatic tone reduction (upto 65dB)

Specifications:

White noise reduction:

level 1 11dB Size:26 x 37mm
level 2 13dB
level 3 19dB Voltage 5 -15VDC
level 4 35dB

Tone reduction:

level 1 5dB
level 2 8 dB
level 3 21dB
level 4 65dB

Current consumption: 45mA

2. Disclaimer

The fitting of the bhi NEDSP1061 module involves the removal of small surface mount
components and the drilling out of the transceivers’ lid. This should only be carried out by
a qualified engineer. bhi accepts no responsibility for the fitting or installation of the
NEDSP1061 module and are not liable for any damage to equipment caused by its fitment.

All attempts have been made to ensure that this information is up to date. It is possible
that these instructions contain errors, or the equipment is slightly different to the one
used to compile this information. In all cases it is up to the installer to ensure that the
module is fitted correctly.

By installing this module you are doing so at your own risk.

Page 2

3. Installation.

This document should be read in conjunction with the relevant Yaesu FT-817 technical
supplement.

The bhi NEDSP1061 module is inserted into the audio path of the transceiver, at a point
before the volume control. To access this point it is necessary to remove the main unit.

Remove any fitted batteries or NiCad pack before commencing installation.
Remove the top and bottom covers.
Remove the 5 main unit fixing screws.
Disconnect all connections - apart from the front unit ribbon cable.
Hinge the main unit forward, over the front unit ribbon cable.

To place the module into the audio path it is necessary to remove the audio signal
coupling capacitor C1338.

The following diagram shows the position of the component.
Carefully remove the capacitor.

Connect the screened lead from the NEDSP1061 module as follows:
Red lead - to R1482 side of C1338 (audio in)
Blue lead to the other side of C1338 (audio out)
Screen to the grounded connection close to the capacitor.
See the following diagram for details.

Q1094

­+

Schematic detail. FT-817

R1268
15K

R1459
10K

C1460
100p

R1317
100K

R1482
1K

Red wire

NEDSP1061

Remove

C1338
100n

Blue wire

To
Volume
control

Page 3