Ripples in the Ether

LogiKlipper Prototype

I recently received a very interesting e-mail from Dave W8NF regarding a very spiffy looking labeling technique that he successfully used for his latest LogiKlipper prototype (BTW, LogiKlipper is going to kick the butt of the RF clipper manufactured by that other company in the South…). Here’s the details on how he did it:

I printed out what I proposed as the “final” lettering artwork on the transparency film.  I included four alignment marks for the corners.  I laid the panel down on newspaper and sprayed the panel with “Elmer’s Multi-Purpose Spray Adhesive” – I got it from Home Depot a year or so ago for another project.

I moved the panel to on top of a magazine that had not been sprayed, and carefully positioned the transparency film over it.  The fact that the film is transparent helped a lot…this would be difficult with an opaque film.

I was worried about bubbles or smudges in the adhesive, and they do indeed exist.  They don’t look as visible as I worried about, though.  They provide a bit of texture, even.

The film is pulling up at the edges…since this was more of an alignment test than a finished piece, I didn’t really work hard to press the film into the panel.  Also, I used a pair of scissors to trim the edges, and that pulled the film up…an X-Acto, bearing against the panel edge, would have avoided this problem.

I X-Acto’d through all the holes, bearing the blade against the metalwork to form scissors.  The only problem points were the countersunk holes.  For a homebrew project, I probably would not countersink.  Or, if I did, I’d have those screws in place before the film was attached, and just glue the film right over them.  The flathead screws, when they went in, wrinkled up the film around them.

I think I’ll try the technique for my next homebrew project.  It certainly serves for what I needed to demonstrate this time.

A very nice looking front panel, Dave! I’m going to have to give this a shot. I’m a lousy mechanical engineer, but I think even I could pull this off respectably.

Dave W8NF has been kind enough to post a short video demonstrating the effect that RF clipping has on a SSB transmission. You can see that peak voltage isn’t affected, but that the power density of the output waveform is increased as the amount of RF clipping is increased. The trade-off is in the sound quality, but that extra bit of processing is helpful for getting more intelligibility into your signal without increasing your output power.