The key to converting your treasured and incredibly versatile FT-817
or similar into a digital powerhouse seems to be an A. computer and B. a sound
card interface.
So, armed with a tidy little Signalink USB interface, I’ve
been attacking digital modes with vigour, starting with WSPR (Weak Signal Propagation Reporting). The Signalink USB
is basically a remote sound card in a box, powered by your computer’s USB. This
solution allows controlled audio isolation between your rig and transceiver.
Level adjustment is available on the front panel too which means you don’t have
to navigate clumsily through several windows on your PC and adjust sliders with
your mouse to optimise levels.
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| FT-817 and Signalink USB Interface |
The interface connects directly to the data port of my
FT-817 and provides a PTT function, if required. However, I’m also using a CAT
interface which provides PTT (Push To Talk) as well as frequency configuration from the
WSPR program that I’ve started with.
So, straightforward then? Nearly but not quite. There are a
few small pitfalls to be aware of. Firstly, the ‘817 needs to be put into DIG
mode as opposed to USB mode. This routes the input and output signal to the
data port on the rear panel. The data port is inactive in SSB modes. Secondly,
the correct data mode needs to be selected in the second-level menu, namely
USER-U. This means that it will be operating in USB mode and the passband will
be adequate. If this were to be set to RTTY or PSK, then the filtering for WSPR
would be too narrow. WSPR signals are individually narrow, but several occupy
the given passband. Finally you need to follow the instructions on Windows
setup that comes with the Signalink box to the letter. One unchecked box or
misplaced slider will drive you to madness.
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| WSPR Control Software |
Apart from that, it seems to be ‘plug and play’! My first
play on 40m with a random wire of some 20m in the back garden pulled in a VK
straight away. I was heard up in the Norwegian Arctic Circle with 1W. Elation.
Simply tuning to 472kHz pulled in a Dutch station with absolutely no special
equipment.
For one whole day I exercised near-military discipline. I
stayed on the 30m band all day long without jumping to other bands. 1W into my rear-garden
wire antenna reached Israel and the Arctic Circle again. East Coast US stations starting
to come in at 20.00 GMT and I was reaching the Mid-West by late evening. Within
ten minutes this morning on 17m I was heard in New South Wales and Iceland.
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| 10 mins on 17m! |
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| 10 mins on 20m! |
I finally unleashed my single Watt on the 20m band for the
first time this afternoon, immediately yielding a nice path to the Philippines
as well as Europe and the East US.
No wonder this aspect of the hobby is so absorbing. I’m
absolutely addicted. Did the developer, Joe Taylor, K1JT, realise what he was unleashing on
us? A ‘big shout’ goes out to the man who invented WSPR!
