(c) Ed Durrant DD5LP 19th. May 2016.
Now, as more and more rigs come equipped with USB interfaces (e.g. Kenwood TS-590, ICOM IC-7200, 7300, 7600, 7700, 7850, Yaesu FTDX-1200 etc. etc) connectivity between a local PC to operate and run digital modes from your PC is possible with a simple USB cable. There is no longer any need for digital interface boxes or special cables, both of these types of solutions bring their driver headaches and other problems. I realise this will affect the coompanies who have produced those boxes at $100 – $500 a shot, but that’s progress.
That’s great news – all you now need is the software – HRD, MMRTTY, FreeDV, MMSSTV, etc. etc. and a computer USB printer lead! Most software is free, at least in it’s basic version and the cable might cost $5. A lot better than $100 – $500+ that it used to cost!
BUT WAIT – THERE’S MORE …..
My investigation have shown that what the (Windows in my case) PC, sees via that USB cable is a serial port for remote control commands (called CAT or CVI by different manufacturers) and an audio CODEC for audio in and out of the rig.
Another area where companies are making a bomb in money is remote station control hardware and software – remote as in control over the Internet from anywhere in the world. There are special interface hardware devices, at least at the station end and some form of special service to get audio to and from the rig (some use Skype, some net messenger, some their own VOIP solution).
GUESS WHAT – the complicated part of these solutions is that VOIP analogue audio transfer capability. Remember what I said above – a PC that is USB cable connected sees an audio CODEC device within the radio? Well, the audio stream transferring between the radio and the PC is NOT analogue audio – it’s digital bits just the same as the control commands to operate the rig are. The next key point now is the arrival of “USB servers” these devices have been around for a while to share printers or hard disks over a network, however the latest type share everything (it’s all digital data after all). The server programs can run on PCs but the latest ones can also run on a smart phone!
Now, stop a minute and think what this means ……
1. We have a connection from a PC to a rig, that runs as a digital link via a USB interface cable.
2. We have the capability to share USB devices across a network, be it a local LAN or worldwide WAN, like the Internet.
Are you with me so far?
Here’s the solution concept: Dedicate an old (in my case broken screen, that I have the parts to repair it but never seem to get around to it), Android smart phone as the USB server and connect it via USB to the rig and via WiFi to your home LAN.
Configure your Internet router to allow data to pass to and from this USB server-phone.
Connect to the Internet from somewhere else with a PC and the client software (with security enabled) which talks to the USB server which is connected to the rig. On the remote PC you see exactly the same connections as we saw on the direct USB cable connected PC in the shack and hence you can run whatever software you wish to use to operate the radio in the home shack while on the road (anywhere). Operate Digital modes (including the original digital mode – CW) or phone modes SSB/FM etc (depending upon what the rig can do of course).
What does all this cost – it depends what you have already.
If you already have a smart phone that runs Android 4 or higher that is spare there’s no cost, if not these can be bought unlocked for around $70 – $80 NEW – second hand cheaper of course.
The control software for the PC, is all available in free versions. Of course if you want to use the one from the rig manufacturer, these are often $80-100 – try a free software package first and add the purchased one later, if the free one doesn’t do everything you wish.
The USB server software that I am using on my Android phone is called “Virtual Here” and is on the Google Play Store as a free download. The Windows client software is also available free from the companies website and is great to try out the solution. They limit the free version however to only controlling one device (i.e. the control commands COM port or the audio CODEC) at one time. Once you are happy the solution is working purchase the version that allows 3 connections (which in our application is sufficient). This costs $40 (one time).
The USB cable to go from the micro-USB port on the phone to the USB-B socket on the back of the rig costs around $10.
This document is a Work in progress and subject to change or even deletion, at any time – but I wanted to put my ideas and findings “out there” for the Amateur radio community as a “give-back” action.