From John, K5ACL
From John, K5ACL
I am about to tackle several projects all at once, in order to operate PSK-31 with my FT-817ND QRP rig. The main reason for this project is the fact I operate QRP with an indoor antenna. In order to make the most out of this setup, going to a digital mode will offer more opportunities for a QRP station. I know there are many of you out there in the same predicament, so please follow along while I put this together.
Not long ago, I re-purposed an old laptop of mine with the Linux, Ubuntu operating system. The laptop is a Dell Studio 1535, manufactured in July of 2008. It has an Intel Core 2 Duo T5750 with 2G of ram. Now this laptop is really getting long in the tooth to be operating the latest Windows® operating systems.
With the new operating system up and running, the next step was to install FLDigi software to run the digital modes.The first place to start is the W1HKJ Software page
Next, scroll down to the chart at the bottom of the page, to the line “Debs for Ubuntu”. To the right of this you will see Ubuntu debs by Kamal Mostafa How To Install from Kamal’s PPA. Open this link and follow the instructions by opening a terminal window (ctrl-alt-t) and entering the set of commands shown, which will install FLDigi.
In order to set up FLDigi for your station, I found this video from Dave, KE0OG to be most helpful.
The next step is to get the Signalink USB interface connected and get on the air. I ordered the unit for the FT-817ND, but all you need to do is follow the instructions for your specific rig. The Tigertronics website has all the information you need. If you bought your Signalink unit new, it will come with a full set of instructions. Before you hook up the unit, be sure you have the correct jumpers installed on the board. The unit comes with the correctly wired cable from the Signalink to the Data port on the rear of the FT-817ND. Next install the USB cable from the Signalink unit to an available USB port on your computer.
If you are running the Ubuntu program, as I am, open a terminal window (CTRL-ALT-T) and type “lsusb”. If you see a USB audio codec device listed, the Signalink has been recognized.
I am going to start on 20m at the frequency of 14.070 MHz. For other bands, you can do a Google search and find plenty of charts listing where to operate PSK-31.
Set the rig mode to “DIG”.
Hold down the F button momentarily to enter the function settings.
F25: DIG MIC GAIN – Set to “40”.
F26: DIG MODE SET – Set to “USER-U”.
Set your power output to 2.5 watts.(display shows L with three bars). There are those that will run the FT-817ND at full power, but after discussions I have had with a few operators, the best recommendation is to operate any rig at no more that half the total power output available. PSK-31 will operate your rig at a 100% duty cycle.
Don’t forget to open FLDigi and configure the operating mode and audio.
Audio Port audio, Capture and Playback – USB Audio Codec.
Select PTT tone on right audio channel
Before making a transmission, I suggest you make a Test TX macro on FLDigi. On the Signalink, turn both TX and RX controls fully counterclockwise (off). On the FT-817ND, set the MTR function to ALC. Then use the Test TX macro to adjust the ALC. Bring the Signalink TX control up until you just see some bars, then back off until no bars are shown. This will insure you have no distortion on your TX signal. If you move up or down the waterfall, be sure to keep checking your ALC level. Bring the Signalink RX control up until you can see some signals on the waterfall without them being washed out by background noise.
Within a few minutes, I managed a QSO with a station in Colorado with just 2.5 watts and an indoor dipole. The signals were not that strong as this is the bottom of the current solar cycle. As you can see by the image below, I am operating a very minimalist station at the moment.
Please consider this operating mode. With QRP (low power output) you will make the most of what your station has to offer.