Wednesday 24 May 2017

Soda Pop 40m CW QRP radio now finished

The finished 40m Soda Pop QRP radio (click to enlarge)

I finally finished the 40m 5W Soda Pop CW radio by Steve Weber KD1JV.

Building the board took about 8.5hours. But preparing the hardware from scratch took a lot longer.

I used a Hammond die cast box and drilled the hole for the controls. I then chain drilled, cut and filed the aperture for the display. My metalwork skills are limited to what I can do in the garage with a Bosch drill and a selection of files.

I ended up having to elongate the holes for the controls and turn the hole for the antenna connection into a slot, otherwise I couldn't get the board in at the angle required. As a result I had to make up a plastic blanking plate for the back.

The box was painted with Plasticote metallic blue and gloss varnish.

The finished 40m Soda Pop QRP radio (click to enlarge)
The panel label was produced using Photoshop and a photograph of mine of Happisburgh Lighthouse in Norfolk (we don't have any summits as it is very flat!).

Once I was happy I then used Photobox to produce five copies of the photograph (in case I screwed a few up) and lacquered that too.

The whole thing was assembled after the front panel was stuck on with red Spraymount.

I'm happy with the result, although I might do the front panel again at some stage to get the hole alignment a little better and also lacquer it with a matt rather than gloss varnish.

Things I learned:
1. Metal cases take a lot of work to get them right!
2. Measure, measure and measure before cutting and filing.
3. When chain drilling, make the aperture too small at first and open it up with a file.
4. Choose a dust free spot to do the painting - a dusty garage floor is not ideal
5. Let the paint harden for about a week to avoid fingerprints.

Now, the fun can start and I can use it a bit more.

So far I have worked Italy, Ukraine, Poland, Germany, and Estonia with it. Many thanks to Steve Weber KD1JV for a great little design.

I'm planning a Norfolk "Bumps on the Air" (BOTA) outing with it quite soon.

Steve G0KYA


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