Notes on interfacing the Tigertronics SignaLink to the Yaesu FT-817 radio - K9JRW --------------------------------------------------------------------------------- I obtained the SL1-NC model SignaLink (comes with Unterminated cable) via www.tigertronics.com for interfacing a Yaesu FT-817 I decided to interface the SignaLink to the FT-817 via the Data port on the back of the radio. Probably could have gone the Mic connector route also but thought since the data port was available it would be better. I had a CT-39 cable from Yaesu for the data port. (Probably could have used any old PS2 cable for this). First order of business was splicing the unterminated RJ45 cable for the SignaLink to the CT-39 DIN cable. Since the SignaLink needs to have the cross connects jumpered inside it, I just connected the cables straight thru - i.e. Pin 1 to Pin 1 etc. This ended up being: SignaLink SLCABNC Yaesu CT-39 ----------------- ------------------- Pin 1 White/Orange<->Pin 1 Black (TX Audio) Pin 2 Orange <->Pin 2 Brown (GND) Pin 3 White/Green <->Pin 3 Red (PTT) Pin 4 Blue <->Pin 4 Orange (9600 bps data) Pin 5 White/Blue <->Pin 5 Yellow (1200 bps data) Pin 6 Green <->Pin 6 Green (Squelch status) Once the cable was made, I did a sanity check by buzzing out a few things and once convinced it was right performed the jumpering in the SignaLink box. On the 8 pin dip jumper block I jumpered: Pin 1 -> MIC Pin 2 -> GND Pin 3 -> PTT Pin 4 -> N.C. Pin 5 -> SPKR Pin 6 -> N.C. I was hoping that maybe the Squelch status line would be sufficient for powering the SignaLink, but it ended up being a 5V signal which isn't high enough for what the SignaLink needs. The other possibility I thought about was jumpering over the 13.5V accessory voltage source to the Yaesu data connector but didn't want to make my interface rig specific. (So i ended up just using a wall wart to power the SignaLink when i wanted to TX and RX.) After a few more sanity checks I hooked everything up and started operational testing. First thing I noticed was the audio line isolation really worked nicely. Much better (i.e. no effect) than an audio cable straight from radio to computer. The receive audio at my computer was fine using either the MIC or LINE level inputs. For PSK31 I switched the Yaesu to the DIG mode and using Menu Item 26 in the radio to set the DIG MODE to USER-U. (I had read somewhere about a 10Hz shift when transmitting if I using the PSK31-U mode). RX Audio came in fine and using Hamscope or Digipan software I was able to decode signals just fine. Now for transmitting. The SignaLink performs a VOX operation to decide when to drive the PTT line into the Data port. I switched the Yaesu meter function over to ALC and gave it a go. The SignaLink did the job and activated PTT whenever the computer was generating tones*, but I never saw any ALC movement. I tried using Menu Item 25 to adjust the input level, but still no ALC on the meter. I believe things may have been OK even with no ALC meter indication, but decided to perform the TX Gain mod on the SignaLink using their notes here: http://www.tigertronics.com/sl_mods.htm After performing this mod I had ALC meter action of about 6 bars on the 50 level DIG MIC setting. FWIW, the DIG MIC could be set all the way down to about 18 without losing this level. * The only possible weirdness i see is if my PSK31 transmit audio frequency is below about 750 Hz, I do not get a PTT activation via the SignaLink. This is easily solved by tuning the radio a bit lower. I am very impressed with the quality of the SignaLink unit and documentation. The web site is also very useful. I think the price of the unit is fair and represents a good value. I have used the unit to now make my first PSK31 contacts (including 2 overseas countries) and am very happy with its performance interfaced to the Yaesu FT-817. Jay K9JRW k9jrw@arrl.net