Re: Using FLDIGI with Vertex VX-1700

Daniel Miranda

Perry and Dave,

I believe I have skipped part of the story in my previous e-mails. My friend has already got the data port to work. It connects directly to the external sound device (Perry is right - not a card!).
I have bought and sent to him two custom cables just like the ones Dave mentioned that have the plug to insert into the DATA port and a different plug to insert into the TUNE port; on the computer side, there is a usb connector and a TRRS P2 plug.  I have also sent two standalone FTDI cables which are supposed to be equivalent to the CT-62 cable mentioned in the manual. I have attached pictures of the cables.
I intend to use the programming software just to test the serial connection, not to program the radio.
The notebooks to be deployed use Ubuntu Linux. I believe the programming software is windows only, but it will only be used for testing the connection.

What works right now:
-sending fldigi's audio to the radio and transmitting (at this time only inside the lab - no antenna involved)
-receiving audio from the radio and decoding with fldigi (my friend generated a thor4 SSB signal at -135 dbm with a bench signal generator and fed it directly into the radio antenna port).

What does not work right now:
- rig control. FLDIGI with HAMLIB configured with the VX1700 alpha profile yields only "hamlib_init: IO error". Configutation details in my first e-mail.
- PTT, since I was expecting to do it with rig control.

What I need:
- Preferably to get a notebook with FLDIGI to control the radio OR
- Alternatively to get basic ptt from fldigi to the radio, which can be done using the several suggestions by David KI6ZHD.
To achieve that I intend to follow the 6 step plan outlined before.

A little more context:
This project is for the Brazilian equivalent of the Mission Aviation Felowship (MAF), it is called "Asas de Socorro" which can be loosely translated as "Wings of Help". They already operate the radios in very remote areas of the amazon forest. The radios are already fully configured and have been operational for years, but voice communication is only reliable at night. Digital modes could improve that and even allow for the transmission of simple documents.
My friend owns a company which sells radio systems for law enforcement, so he is very knowledgeable of radio systems in general but new to amateur radio digital modes. He has a lot of high end lab gear and happened to have a VX1700 in stock. I believe he had/has a ham license but has been away from the hobby for a long time.
I am a computer engineer and have a MSc in signal processing applied to satellite attitude control systems. I work in law enforcement with geographical information systems.

I have attached pictures of the cables I have available for testing.

I am really amazed by the lightning fast responses on this list. Thanks to all.

Em seg, 24 de set de 2018 às 00:42, k4pwo <k4pwo@...> escreveu:

You want the “DATA” jack which is a 6-pin mini-DIN connector.  The sound cards produce analog audio, not serial data.

You can get this cable…

…and cut it in half and make two cables by putting the necessary connectors on the cut ends you need for the sound devices (can’t really call external sound devices cards).


Perry K4PWO


From: <> On Behalf Of Daniel Miranda
Sent: Sunday, September 23, 2018 9:17 PM
To: Group Moderators <>
Subject: Re: [nbems] Using FLDIGI with Vertex VX-1700


Hi, David! Thanks again for the tips!


1. I'm not absolutely positive digital modes would be allowed because I do not have the actual text of the spectrum licenses, and public documentation is scarce on bands outside the amateur ranges. That being said, I found no obvious legislation precluding digital modes and the frequencies are exclusive, so, from a purely technical standpoint, there would be no interference with other stations. I will look into that as it is obviously important.


2. About the sound card setup: I researched signalink before, and I think it is awesome hardware, but the project is cost sensitive. The notebooks themselves are under $300 with shipping. I build a setup at home with simple external USB sound cards (about $10 each) and did a cross connection between two notebooks just to make sure I got a grasp of the concepts involved. The sound cards can be bought in a larger quantity so as to be easily replaced in case of failure. Spurious sounds like notifications are disabled since the notebooks are shipping with a plain Ubuntu 18.04 installation that I control. They will have only fldigi and the bare basics for operation in the field. Also, I will ship an SD card with the entire installed OS and a field manual so that if something goes wrong, the operator just plugs in the sd card and boots into a fresh OS install.


3. About the pinouts, I read in the manual that VX 1700 supports the CT-62 cable, which connects to the mini-din 6 port labeled TUNE (I double checked that, since it sounds really odd), not to the GPS port that is on the CAT protocol documentation (the one that the other Dave - W1HKJ mentioned) . The pinout for that port ( reveals that it supports the serial protocol, and it does not seem that it is necessary to flip any switches in the radio. 


This is my plan for the moment:

a. Look into the frequency licenses and make sure they allow digital mode operation (or CW at the very least).

b. Try to write an XML definition as Dave W1HKJ mentioned.

c. Failing that, try to hook up the official programming software to VX1700 to narrow down the problem. If it just works, the issue is with FLDIGI configuration, if it doesn't I need to try another computer or buy new cables. My friend got in touch with a supplier yesterday and he should have the software available sometime next week.

d. If the official programming software works, write a small program to try every possible serial port combination to try to get an answer from the radio.

e. Failing that, hook an oscilloscope to the CT-62 cable wires and listen to the VX1700 official programming software talk to the radio. In that case, I will have to get a plane ticket to visit my friend - which would be very nice but expensive.

f. Failing that, it's either your solution with the transistor or vox. I'm not prepared to invest in the signalinks yet, as after taxes and shipping they would be almost $200 each.


Thank you for the time you put in your answer. Also, I have to ask: is it ok to have technical discussions like this in this list? If it is inappropriate I will continue them privately.





Em dom, 23 de set de 2018 02:31, David Ranch <linuxham-fld@...> escreveu:

Hello Daniel,

Well, I would encourage you to make sure that running digital modes on those other frequencies is allowed from the local government(s) and for the operators there.  Assuming they are and you're just starting out, you can either easily build yourself a soundcard setup for cheap but if you lack the skills, time, patience, you could opt for a ready to go soundcard setup like this:

   $115 -
   $5 -

Regardless of the HW you setup, I *do* recommend to run a different sound card than whatever is built into your desired computer.  Too many issues come up with trying to reuse one sound device for all things.  Audio Levels get messed up, notification sounds go over RF by accident, etc.

You can see lower down in the following URL that most Yaesu radios are listed as supported:

I tried checking in the Yaesu / Vertex VX1700 manual that the pinouts are identical with say the Yaesu FT857 but the manuals there don't have any pinout details:

  - NOTE: I see that 9-pin serial connection is NOT labeled for CAT control, it's labeled for GPS for SELCALL support.  The URL that W1HKJ posted includes instructions that you have to open up the radio and flip two DIP switches to get CAT control to work.  Kinda a pain but at least it looks possible.

Anyway.. I'm quite sure this will work for you but if you're going to make all this pretty "fool proof", I recommend you get a test VX1700 radio, a soundcard like this, and a test computer to run Fldigi on.  Fldigi will work fine on anything from a Raspberry Pi, an X86-based tablet (not an ARM processor based one), or any laptop running Windows, Mac, or Linux.

Btw.. no need to us VOX.. the above Signalink unit will do the PTT for you but it doesn't include a serial port for rig control. 


On 09/22/2018 07:27 PM, Daniel Miranda wrote:

Hello, David! Thanks for the suggestion!


 If I have to give up rig control, I was thinking about configuring vox. I would need only one cable, no active components and everything would be simpler. Fldigi supports introducing a tone before the main transmission which would be ideal for that.


I feel a little awkward asking for help here because I have no ham experience and I don't even have a callsign (I don't legally need a license since I'm not the one operating the radios :-)). But I am trying to help a worthy cause, so thanks for your input and your patience.








Em sáb, 22 de set de 2018 22:38, David Ranch <linuxham-fld@...> escreveu:

Hello Daniel,

Regardless of rig control, Fldigi should work just fine with that radio as it looks like a regular Yaesu radio from it's back side.  Connecting the the DATA jack to a sound card for audio IN/OUT and using a serial port's RTS pin through a three part transistor circuit should work fine.



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