Yaesu FT-817 / FT-100 SoundCard Interface
Table of contents
The purpose of the SoundCard Interface is to connect the Computers Soundcard
to the Radios NF In and OUT Pins and (to some degree) to reduce noice and hum on the cable. This
is accomplished by two NF Transformers. I know, there would be better, more sophisticated Ways
to do this (like optical isolation etc.) but the way I did it is cheap, simple, easy to build
and is small in size (and til now it works good).
THIS CABLE IS JUST ONE WAY TO CONNECT YOUR RADIO TO A PC - OTHER, MAY BE BETTER WAYS,
MAY EXISTS - IT'S UP TO YOUR RESPONSIBILITY IF YOU BUILD AND USE THIS CABLE. UNDER NO
CIRCUMSTANCES I AM RESPONSIBLE FOR ANY DAMAGES TO YOUR RADIO OR PC! THIS DEVICE WAS
TESTED WITH DIFFERENT RADIOS AND PC'S AND UNTIL NOW IT WORKS WITHOUT PROBLEMS.
The Schematic is so far very simple. Just two NF Transformers and two
Trimmers to adjust the NF Levels - that's it.
Image 1: Soundcard-Interface
The Box can be used in combination with my Cat Interface Cable as you can see
on Image 2.
Image 2: Cable overview
Sorry there is no PCB available at the moment. The reason is that I try to
include a Tuning aid (like One Touch Tune) in the Box. If this is finished
I will make a PCB for the Box. For now it is just prototyped on Perfboard
as you can see on the Pictures.
Pictures of the finished Box
Image 3: Interface Box
Image 4: Close Up of Box
Image 5: Mounted Box - Front
Image 6: Mounted Box - Back
Image 7: Mounted Box - Side
Notes & Comments
Some notes to the Box:
If you have any comments or sugestions just drop me a line.
- You can mount it with double sided Tape on the FT-817 (see Pictures)
- Always use good quality NF cables. I had big troubles with cheap
NF cables for PC speaker systems from the next computer store. First I
thought the fault lies in the Box but after some investigation I found
out that the cables made the problems. The
shielding of this cables is very poor. I now use self made cables with
good quality plugs and they work as they should.
- For the 6 and 8 Pin Mini DIN Plugs and Sockets you can use Cables from
your next computer store but be sure that ALL Pins are connected from Socket
to Plug. On some cables this is not the case. Or if you have a soldering iron
with a very fine tip you can solder them yourself (but be warned - it's a realy
boring job ;-)
- Specification about the used NF transformer can be found in
this PDF. Unfortunately it's in german but the
figures should speak for themselfs.