Thursday, May 25, 2017

Read the manual? Hah!

Well, read a little.  Just from the Dire Warnings in the four-page SignaLink docs.  Really though, the SignalLink box opened up without catastrophe (despite the Dire Warnings), the jumper board slid in without incident, and the linux laptop recognized the USB device without complaint.  Checked things out step-by-step, listening & decoding a few traces first, then test transmitting a PSK31 signal at 5w into a dummy load, then listening on the Mon and Aux output on the link box, then tried to listen to a signal on a portable shortwave with the antenna folded down and attenuators fully cranked.  That simply overloaded, but at least I could tell things were keying up properly.  Then there was nothing to do for it but to dive in.

Berzerk traffic on 20m, couldn't get a word in edgewise, but 40m had a few things going on and I quickly got an answer from NY.  Then down to 30m, just because its a favorite, where a guy from Guatemala answered right away.  Good signal reports all around.  Remember kids, crank your power down to about 20%.  Clipping is poor form and J. Willard Gibbs is not your friend.

Compared to the old iPhone audio trick, there were about twice as many PSK31 signals visible and readable using the SignaLink box.  That in itself is worthwhile.  By using a manual notch filter to chop out the loudest splattering signal (there's always going to be one), I was able to crank up the RX gain and pull in some weak traces that would have otherwise gone unnoticed.  But I'll still keep the iPhone trick in my pocket for days on the trail.

So yeah, totally worth the outlay.  Next up: RTFM for fldigi (the digital mode software) and neaten up the entire thing, both in terms of cabling and in the software configuration.  Then... get on the air for a while.  Next Up for the linux laptop: Slow scan TV.  Eventually.

So all three "Down to Work" objectives from last Sunday's post achieved, minus the fiddly tuning that will only come with time and some RTFM'ing.  This is a good staycation.

Time to spruce up the place with more pictures.  This magic box is small, think "fat deck of cards" small.

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