SGC FT900 User manual

FT900 Transceiver
Low Power ADSP2Installation
Catalog Number 70-11
SGC Inc. SGC Building, 13737 SE 26th St. Box 3526 Bellevue, WA. 98009 USA
Fax: [phone], Tel: [phone] or 1-800-259-7331
E-mail: [email protected] • World Wide Web: www.sgcworld.com
©April 2003, SGC Inc.
This document describes procedures that could result in voiding of the warranty of your radio.
If these procedures are not precisely and properly carried out, it could result in a radio that does not work or is damaged.
Furthermore, while reasonable efforts have been made to assure the accuracy of this information, it is possible that there are some errors, or that your radio is of a slightly different
version than the one used for testing and thus, differences may exist. You are expected to take total responsibility for your own actions.
It is assumed that anyone following suggestions made in this document is already thoroughly familiar with the technologies and techniques involved and possesses the necessary
skill and knowledge to make their own judgment as to the appropriateness and validity of the information.
If you choose to do the installation outlined, you do so at your own risk. You are solely responsible for any damage, voiding of warranty, or other harm that may come about
by following these procedures. It is very strongly recommended that, if you maintain your own radio, you thoroughly familiarize yourself with the transceiver service manual.
If you don't have one, get one!
CAUTION: Soldering and desoldering of very small Surface Mount Components may be required to perform this installation
IMPORTANT NOTE: Support for the ADSP2board will be provided by SGC
exclusively by email. Please write to [email protected] for assistance if needed.
1. Technical Specifications
Specification Low Audio High Audio
Size 1.7 X 1.475” 2.645 X 1.475”
Weight 0.6 oz 1.1 oz
Audio Limits
Min Input 10 mv RMS 100 mv RMS
Max Input 150 mv RMS 5 volt RMS
Max Output .5 v RMS 9 v RMS
Power Output 5 Watts RMS
Current Consumption
idle 80 mA 110 mA
full out 80 mA 500 mA
X1 X2
Noise Reduction 13 dB 26 dB
Time Delay 6.5 ms 13 ms
Tone Rejection -50 dB -65 dB
Filters (3dB Bandwidth)
Voice 300-2100 Hz
CW Wide 400-900 Hz
CW Narrow 600-700 Hz
Out of Band Rejection -45 dB

FT900 Transceiver
Low Power ADSP2Installation
Catalog Number 70-11
SGC Inc. SGC Building, 13737 SE 26th St. Box 3526 Bellevue, WA. 98009 USA
Fax: [phone], Tel: [phone] or 1-800-259-7331
E-mail: [email protected] • World Wide Web: www.sgcworld.com
©April 2003, SGC Inc.
2. Preparation
The ADSP2installation provides you with an unprecedented ADSP capability, far beyond
what you can find on most amateur radio transceivers.
Every possible effort has been made to provide you with a simple, easy to use product.
One where you can concentrate on your communication and not on fiddling with knobs.
SGC’s ADSP2will give you years of service improving your ability to communicate.
¨Prepare your work area
¨Assemble your tools and parts
ADSP2board
ADSP2switch assembly
Double-stick tape for mounting the board
Tools for disassembling your transceiver
soldering iron suitable for working with Surface Mount Devices
3. Install the ADSP2Board
¨Open your transceiver
¨Remove the backing from the double-stick foam tape and
attach the ADSP2 assembly into a convenient location
We shoes to mount the board on the vertical board behind the front panel. This location
was convenient and allowed us to run the switch wires out to the left side in the picture
below. There was no convenient hole through the transceiver’s case, so we filed a small
gap between the front panel and the front panel just to the left of the yellow tape in the
picture to allow us to run the switch wires outside of the box.

FT900 Transceiver
Low Power ADSP2Installation
Catalog Number 70-11
SGC Inc. SGC Building, 13737 SE 26th St. Box 3526 Bellevue, WA. 98009 USA
Fax: [phone], Tel: [phone] or 1-800-259-7331
E-mail: [email protected] • World Wide Web: www.sgcworld.com
©April 2003, SGC Inc.
¨Connect the ADSP2 into the signal path
The following connections will be made between the ADSP2 board and the transceiver:
Pin 7 to 12V DC, White wire
Pin 9 to DC ground, Black wire
Pin 8 to audio in to the ADSP2, Gray wire
Pin 10 to the audio out from the ADSP2, Brown wire
You will also need to make the following connections to the board from the momentary
switches provided for switching ADSP modes and Filters:
Pin 4 to the Yellow Wire
Pin 5 to the Red Wire
Pin 6 to the Black Wire

FT900 Transceiver
Low Power ADSP2Installation
Catalog Number 70-11
SGC Inc. SGC Building, 13737 SE 26th St. Box 3526 Bellevue, WA. 98009 USA
Fax: [phone], Tel: [phone] or 1-800-259-7331
E-mail: [email protected] • World Wide Web: www.sgcworld.com
©April 2003, SGC Inc.
The picture below shows these connections:
The audio path should be broken at the input to the audio amplifier just before the volume
control. The only requirement at this point is that a minimum of 10 millivolts RMS and a
maximum of 150 millivolts RMS will appear at this point when using the Low Power
version of the ADSP2. Normally, there is a capacitor at this point (0.1 uf is a typical
value) to couple the stages together. Remove this capacitor and connect the ADSP2board
in its place. The board has coupling capacitors on its input and output.
Pin 4 Yellow Wire
Pin 5 Red Wire
Pin 6 Black Wire
Pin 10 Audio Out
Pin 8 Audio In
Pin 7 12VDC
Pin 9 Ground

FT900 Transceiver
Low Power ADSP2Installation
Catalog Number 70-11
SGC Inc. SGC Building, 13737 SE 26th St. Box 3526 Bellevue, WA. 98009 USA
Fax: [phone], Tel: [phone] or 1-800-259-7331
E-mail: [email protected] • World Wide Web: www.sgcworld.com
©April 2003, SGC Inc.
SGC recommends removing the C1174 coupling capacitor and connecting the audio
in/audio out connections across where the capacitor was.
C1174

FT900 Transceiver
Low Power ADSP2Installation
Catalog Number 70-11
SGC Inc. SGC Building, 13737 SE 26th St. Box 3526 Bellevue, WA. 98009 USA
Fax: [phone], Tel: [phone] or 1-800-259-7331
E-mail: [email protected] • World Wide Web: www.sgcworld.com
©April 2003, SGC Inc.
12 VDC can be taken from any point where it is convenient and the ground can be
connected to any convenient point which is connected to the chassis ground. There are a
number of suitable locations to connect 12 VDC and GND. We chose to connect to
R1376 to get 12 VDC and to scrape clean a point near C1360 to tack to the board ground
plane.
Location
of C1174
GND wire
tacked
directly to
ground
plane
R1376 –
12 VDC
(under the
wire
bundle)

FT900 Transceiver
Low Power ADSP2Installation
Catalog Number 70-11
SGC Inc. SGC Building, 13737 SE 26th St. Box 3526 Bellevue, WA. 98009 USA
Fax: [phone], Tel: [phone] or 1-800-259-7331
E-mail: [email protected] • World Wide Web: www.sgcworld.com
©April 2003, SGC Inc.
¨Route the ADSP2switch assembly out of the transceiver
body
¨Connect the switch assembly to the switch wire connector
¨Reassemble the transceiver
4. Test your transceiver
The switch buttons are assigned to their functions according to the diagram below:
Each switch steps through its functions in order as shown below under testing.
¨Testing the ADSP Functions
R1376

FT900 Transceiver
Low Power ADSP2Installation
Catalog Number 70-11
SGC Inc. SGC Building, 13737 SE 26th St. Box 3526 Bellevue, WA. 98009 USA
Fax: [phone], Tel: [phone] or 1-800-259-7331
E-mail: [email protected] • World Wide Web: www.sgcworld.com
©April 2003, SGC Inc.
oPress & Release the ADSP2Pushbutton for Noise Reduction X1
oPress & Release the ADSP2Pushbutton for Noise Reduction X2
oPress & Release the ADSP2Pushbutton for No Reduction
oRepeat several times to verify operation
¨Testing the Filter Functions
oPress & Release the Filter Pushbutton for the Voice Filter
oPress & Release the Filter Pushbutton for the Wide CW Filter
oPress & Release the Filter Pushbutton for the Narrow CW Filter
oPress & Release the Filter Pushbutton for No Filter
oRepeat several times to verify operation
5. Installing the Switches
The switches may be installed in any convenient location. The specific choice of switches
was made to make it easy to mount on nearly any transceiver. Some people have chosen
to install their switches on the side of the unit, others have preferred the top, and some on
the front. Your specific installation will determine what the best location is.
SGC mounted the switches on the FT900 on the right side when looking at the front
panel.
SGC welcomes any suggestions regarding these switches to improve installation and
operation.
CAUTION: Overdriving the ADSP2 module may cause distortion. Backing off the level
of the input signal will avoid it.