Yaesu FT-857 series User manual

Installing a LIF port into the FT-857/897 transceiver
Introduction
This document describes the procedure for installing a LIF (Low Intermediate
Frequency [9 – 18kHz]) port into the FT-857/897 transceiver. This procedure
requires a level of expertise sufficient to dismantle the transceiver and to solder.
Nonetheless, the installation is straight forward and should not cause any
difficulties for the experienced radio amateur.
It is important to unplug all connectors and power before working on any
transceiver. It is also important to be grounded to avoid static discharges.
Please note: no responsibility or liability will be taken by the author of this
document for any damage or malfunction caused by user modifications.
LIF port installation
Dismantling the Transceiver
The top cover of the radio must be removed. There are 7 screws that need
to be removed and then the lid will become loose; there are 3 screws on
the top cover and 2 on each side. Remove the lid carefully; the speaker
cable will still be connected to the circuit board. Unplug the speaker.
Connecting the RG174 cable to the PCB
Solder the ground shield of the RG174 to the first 3 pins of J23. This will
also make the option filter 1 selectable in the radio’s menu. Pin 4 is the RF
and it needs to be connected to the center of the RG174 coaxial cable and
to the input of the 455kHz filter. The center pin of the filter is connected to
pin 2 of J24 and the output is connected to pin 3. The filter is secured on
the PCB with double sticky tape. The filter will keep the AGC function

working. The audio of the radio has to be turned off. Pin 1 of J24 stays
empty.
Note: The bridging filter is optional and is not supplied with the kit.
Note: Option filter 1 has to be selected for RX to route IF to the LIF.
Routing the cable and reassembling of the transceiver
The best routing of the RG174 is shown below for the FT-857. The coaxial
cable is secured with a tie-wrap to the power cable. The LIF PCB has to
be mounted outside of the transceiver.
The best routing of the RG174 is shown below for the FT-897. The LIF
PCB can be mounted inside the transceiver. The PCB has to be made
slightly smaller to fit into the gap, as shown, with sand paper. Power is
provided though the regulator IC on the upper PCB. Use the +12V side of
the regulator IC. The LIF PCB has its own regulator.

Connection of the LIF converter (RX-only)
The LIF RX output of the transceiver connects to the IN port (TB1) of the
LIF assembly and the audio Line out (TB3) connects to the tip line-in of
the sound card. TB2 provides power (+12V). TB5 is not used for the RX-
only version. A jumper has to be placed on TB4 between 3-4 to by pass
the 7kHz high pass filter or between 4-5 to enable it.
Note: The transmit audio is still filtered with the existing filter inside the
FT-857/897. If the MDSR is properly configured the standard microphone
can be used to transmit, while the RX is processed through the computer.
For more details see “Lock to TXCR” the MDSR help menu.
Setup of the CAT interface
The MDSR software controls the transceiver via the CAT port. The
connector cable CT-62 is the Vertex Standard version of the interface
cable that plugs into the back of the radio and the RS-232 port of the
computer. There are also virtual RS-232 cables available that connect via
the USB bus to the computer.

OmniRig Setup for the FT-8x7 series transceivers
To enter setup menu in MDSR-SA select the tool icon at the bottom right
and select “OmniRig Configuration & Status”, select the key icon
“Configure OmniRig”. Only configure RIG 1.
•Select the transceiver to be controlled
from the drop down menu (FT-857 or
FT-897).
•Select the port of the computer. If the
Com port is not known go to the
“Device Manager” and select the ports
icon. The port number should be listed
there.
•The Baud Rate has to match the
setting in the Transceiver. The default
setting for the FT-857/897 is 4800. It
can be changed to a higher
performance if needed (see transceiver
manual).
•All the other settings should be as
displayed here.
o
That completes the installation of the LIF port of the FT-950. The MDSR team
wishes you all the best. If you like the performance of the MDSR software please
tell all your friends about it.
73
The MDSR development team
To order the PCB kit or for more information please go to;
Note: if you are interested in the TX – BiLiF option contact VE7DXW directly.
http://users.skynet.be/myspace/mdsr
specify 455kHz IF