View Full Version : Yaesu FT-897 and PSK-31
05-10-2010, 02:34 PM
I had a lot of fun last night getting started with PSK-31 on my FT-897. However, the way I've rigged my equipment to accomplish this leaves much to be desired -- A computer mic on top of my rig to catch incoming signals, and my radio mic right in front of my speakers to send outgoing signals. I'm running Digital Master 780 out of Ham Radio Deluxe. Is there a cable I can get from Yaesu that would allow direct connection to my computer sound card? If so, which one? I have a CAT cable running to my computer, but that's just for controlling the radio, not the audio itself.
Also, different topic, what does "FB" mean? I saw that used a good bit while fooling around with PSK-31 last night.
Thanks for the help!
TD - KI4YZI
05-10-2010, 02:37 PM
"FB" is short for the term "Fine Business"
Think about this like you are connecting a home stereo system to your TV/ DVD player set sort of thing.
Also keep in mind we are using "mono audio" for our radio communication purposes so it's not required to wire in "both wires" on 3.5mm plug - IE. two channels (right and left - stereo) etc into this wiring configuration.
Shown below is a basic simple wiring arrangement that uses the rigs regular speaker output jack and microphone jack connections to achieve the intended goal.
So, while the above example doesn't use an ACC jack to accomplish the goal of digital mode operation, The ACC connector on the rear of the rig can also accommodates the same functions as the idea shown above.
Of course, there are more complex and elaborate ways to achieve the "interface" connections.
For example, many "commercial" interfaces costing $100's of dollars will also include opto isolator and electronic switching circuity. Some also include the idea of "auto level" audio control or they may incorporate an auto sensing PTT switching device to TX the rig etc etc..
However, the diagram shown is intended as the basic bare bones concept interface to achieve digital mode operation which works well in a manual RX/TX configuration. You can simply use the manual TX button on the front of your rig to initiate the digital mode transmissions without installing all the extra automatic techno fluff.
Also, instead of using an external "interface box" like the rigblaster or other similar interface box does etc, to make all the necessary wiring connections and audio level adjustments, you can also simply make your audio adjustments in Windows using the "Volume Control" interface in your control panel which serves to adjust your soundcard settings in the same way, but it's on your desktop instead of inside an external interface box.
Hope that helps to get you thinking "outside the box"
I'm using essentially the same thing that KC8VWM described, and it works just fine for me. Here's a description of the setup for the FT-817, and I assume that the 897 has an identical plug in back.
If so, you can cut the plug off an old computer mouse and use that. The other parts, if you don't already have them, won't set you back more than a couple of bucks.
The FT-817 doesn't have "digital VOX", so you will need to manually switch between transmit and receive. But I've found that it's not much of a hassle to do so. One of these days, I'm going to get a "real" digital interface for other modes. But for PSK31, the minimalist approach seems to work fine.
05-10-2010, 05:31 PM
You definitely want to use the ACC port instead of the normal mike and speaker connections. The audio output on the ACC port is not controlled by the AF Gain (volume) control, so you can mute the regular audio output or just turn the volume way down without changing the settings for receiving the signals. I believe on your 897 that using the ACC port in 'digital' mode will also cut off the normal mike input, so noises in the shack aren't transmitted on the air, and again, with a bit of effort, you can find the right comibination of mike gain and audio out from the computer so you can go back and forth between voice and PSK without having to change settings.
A PS2-style mouse connector (6 pin mini-DIN) is correct. You can buy preassembled cables with the mini-Din on one end fairly cheaply from many sources, including Allied. http://en.wikipedia.org/wiki/Mini-DIN_connector
I personally prefer to have some isolation between the radio and computer audio circuits. This eliminates the need to worry about ground loops and potential hum being transmitted along the line. Radio Shack carries a couple different audio transformers, and I think this is the one you want: http://www.radioshack.com/product/index.jsp?productId=2103254&CAWELAID=107597296 Sadly, their website doesn't reveal if this is their 1:1 transformer, or some other ratio. If you can find one in their store, it is marked with the ratio. You want 1:1.
I also find that a resistive pad like the one in the previous post is often needed on both receive and transmit side to bring signal levels down to usable levels. Ideally, you want the computer audio levels set to mid-range, and you want the mike gain on the radio adjusted so that it works for both PSK and the normal microphone.
The other big advantage of a commercial interface is that it provides a way of keying the radio PTT. I believe the FT-897 has a 'digital VOX' circuit that will work, but you must be certain that your Windows beeps and squawks aren't transmitted on the air!
05-11-2010, 04:17 AM
"For example, many "commercial" interfaces costing $100's of dollars will also include opto isolator and electronic switching circuity."
Or these roll your own, from the same page where KC8VWM got his atenuator cable schematics. (I'd add audio isolation transformers to those cables, but that's just me. They're only $2.99 at Radio Shack, the same page has the part numbers:
There are PTT circuits with plain switching transistors with a DB-9 cable,
or some using an optoisolator, all parts available from Radio Shack.
Yeah a few interfaces cost "hundreds of dollars" but **most** are far cheaper, they and DO have optoislators for PTT and audio isolation. if you decide not to roll your own, you can get a RigBlaster Plus for $160 not a bad deal, serial cable or USB.
Lotsa folks like the Signalink USB. Never used one yet. I see the appeal of a seperate sound card from your computer, howeever... do a Google Search on 'Signalink HRD/DM780 Hookup Problems' and see how many people have trouble getting these configured.
Just an **observation**....no flames please.....I'm NOT Anti-Signalink
and not anti HRD/DM-780. Maybe the starters of those threads are all
troglodytes. Had my RigBlaster and DM-780 on the air with PSK & RTTY 5-10 minutes after download.
05-11-2010, 05:19 AM
I've used the Icom version of these with good results:
Donner Digital Interface
for the 897:
You want the 2nd one on this page, the Yaesu Cable-1 KIT
If you are interfacing with a laptop, which does not have "Line In", just mic input, you might be better off with this Behringer UCA202 USB sound card.
You will need some 1/8" to RCA phono plug adapters. Use just one channel, either left in/out or right in/out.