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Archive for April, 2007

Remote Control – a Road Warriors Delight

Posted by on April 2, 2007

Remote Station Control

As I mentioned below, I read a very interesting article in QST last week while flying home from Wisconsin. Unfortunately, I left the magazine in the plane, so I don’t have the reference information, but I’ll dig it out and post it ASAP.

As a reluctant road warrior, I’ve been missing out on a lot of operating lately, and particularly miss the regular net checkins etc. So you can understand my interest in remote station control over the internet! It was difficult to sit still on the plane, I was so keen to get home and try out some of the ideas, and began making plans immediately.

I was familiar with Skype, my wife and I use it to chat when I’m away, and for my money, it definitely has the best audio quality of all the various chat programs, and I find it to be very stable in the XP environment.

Audio Setup

I installed the latest version on my shack PC, and using the same cables I use for PSK operation, had radio audio on my remote laptop in no time at all. The audio from the rig feeds directly to the mic input on the sound card, and the headphone jack on the PC is connected to the mic input on the K2 via a 10:1 resistor attenuator.

Rig Control

I had a copy of Ham Radio Deluxe on the desktop and noticed that the latest version does have a remote server option. A quick read of the manual indicated that this would work quite nicely as long as I could access the shack PC remotely from the internet.

The next step was to configure my DSL modem and wireless router to pass through IP traffic addressed to the modem directly to the shack PC. This required setting up a DMZ (a range of IP addresses not protected by the router firewall) and configuring the router to pass through the specific port to the local IP address of the shack PC on the internal network.

This part can be a little tricky if your not at least a little familiar with IP networking, but there is information on the net, and most Ham Clubs probably have a few people who could assist you with this. If you’re a complete Networking Novice, I suggest you try and get some help as you could either hose up your internet connection or open your network to malicious programs and people (which is why I haven’t provided any more details on this post…)

Once this was done, I was able to use the IP address of my DSL modem (assigned by the phone company, and somewhat temporary) to set up the Ham Radio Deluxe remote server. The QST article describes how to set up a domain name that will dynamically track any changes to the IP address assigned by the internet service provder. Before attempting this, I made sure I was able to run HRD in local mode on my shack PC connection to my K2 with the standard serial interface. This was very easy to do, and provided excellent rig control features.

Ham Radio Deluxe Remote Server

There are two steps to setting this up. First, I enabled the remote server service on the shack PC, which starts up with the PC, and essentially runs in the background “listening” for a remote host to connect. So far I haven’t noticed any negative effects of running this service. Clicking on the big “Remote” button in HRD opens a window with instructions on how to edit the configuration file (with a simple text editor) to set up usernames, passwords, ports etc. Simply follow the instructions in the help to edit the file, save it and start the service. At this point the shack PC is ready to accept a connection from a remote PC running HRD.

HRD Remote Connection

On starting HRD, select “NEW” on the initial connection screen to setup a remote connection. On the following screen, select company & radio (Elecraft K2). Choose “Remote” on the drop down list for COM Port and select the appropriate speed (4800).

New Connection Screen

Press the “Connect” button to pull up the next screen. Here you enter the details for the remote connection, including IP address, port, username and password (I haven’t shown this for security reasons.) I haven’t tried it, but I believe you can either enter an IP address directly, or a domain name of your choice (once you set it up on a DNS as described in the article…) Check the box to save the settings and press the connect button. If all went well, you’ll see a dialog box asking you not to break anything and you’ll be connected to the radio.

Adding Video

As a born skeptic, I wanted to have some positive feedback that the rig control software was working before going on air remotely, so I grabbed my webcam and pointed it at the K2 display, nice and close. It took a little to adjust the light and angles to get a good view of the S meter and display, but the Skype video gave me an excellent view even in a small window as show in the picture above. This gave the added advantage of being able to see messages not normally shown on the HRD interface, like the SWR after tunning the ATU.

Remote PC Control

As indicated in the QST article, initially I used a remote PC application to set things up. Being cheap, I decided to use the free utility built into Windows XP, Remote Desktop Connection. This is relatively simple to configure, once you have access to the shack PC, and again, I just used the IP address directly, but it will also work with a host name.

Remote Desktop works well on a high speed connection, but is a little clunky at lower speeds. I did notice one bug when using it, I wasn’t able to select the correct sound devices on the Skype config – it displayed junk text in the drop downs… As a result of this, I set up Skype on the shack PC to answer automatically, with the video enabled. This alieviated the need for a remote connection for normal operation, but it is handy for trouble shooting should the need arise.

Putting It All Together

 At this point, I had the audio connection into and out of the K2 with Skype and HRD running remotely to control the rig. It was time for some on air testing… I called on the local 2m simplex frequency, and a little while later had a volunteer (Keith, K5YCM) to help with on air HF testing. The moment of truth was here!

As with any worthwhile project, it didn’t work the first time… Keith reported a lot of echo, and what sounded like an audio loop of some kind providing long delay reverb. Basically, the signal was unintelligible! Keith was able to make a recording and email it to me for further analysis. (For someone first licensed in 1959, Keith sure knows his way around a 21st century ham shack…)

So, it was head scratching time… I listened to the audio file and it sounded like there was some kind of feedback loop between the transmit and receive audio on Skype, with about a 1 second delay. It turned out that using the remote desktop software had corrupted the sound device settings in Skype (as mentioned above) and once these were reset, the audio jumped into life.

  • Another call to Keith for a report and we were away. I had a remote station working with effective audio and full rig control! This stuff is SO cool when it works…

Next Steps

At this point, I’m not transmitting unless I’m in the house, or my wife is available to switch off the trasmitter if anything goes wrong. In order to comply with FCC regulations, I’ll have to set up a more positive control of the transmitter, and I’ll include a dedicated hardware time out timer in case I lose communications. The QST article details some methods of achieing this, and that will be the topic of a future article. In the mean time, Mendy will have to be my fail safe when I’m on the road…

Comments and Questions

Please feel free to leave comments on questions below, and I’ll see what I can do to help you out if you’re interested in trying this out – it’s great fun even if you don’t travel…


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I’m back…

Posted by on April 2, 2007

Sorry for the long absence – things moved very quickly at work over the last couple of months, and consumed most of my spare time. I’m traveling a lot at the moment, splitting my time between Fort Smith, Wisconsin and South Carolina.

This brings me to the theme of my next post, which is in direct response to the article in QST this month on remote station control using Skype. Unfortunately, I left my copy on a plane in Dallas last Friday, and can’t reference it here. As soon as I can locate the reference information, I’ll post it here.

Hope you find it somewhat interesting, and I’ll try and get more posts up in coming months.



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