last update: 2010-03-08

Well, it seems this is not going to be a one day's job, so we'll keep this page "under construction" for a while....

Home

    In january 2009 I visited the Jan Corver Museum in Bladel in the south of The Netherlands. They have/had a special exhibit, called "Secret messages" that is/was dedicated to cipher and decipher equipment like Enigma and miniature radio's. And there it was again, that intriguing little radio, called Paraset. I wanted one! It felt like I had caught a virus!

    That weekend I googled for "paraset" and read almost everything that was of any interest. I came on many web sites and discovered that there are many people like me, with the same symptoms: we all desperately need a Paraset. I discovered that the only way to come over this serious infection, was to build one myself. I also learned that there is no guarantee that building a Paraset will cure the infection. On the visited sites I learned that many people built more than one. So I hope for the best and start with building just one. As a precaution I gathered enough parts to build more than one, if necessary. As Lord Baden-Powell always stated: "Be prepared!"

First I started to inspect various junk boxes if any useful parts could be found. Some tubes turned up and mounting struts. And two beautiful RF chokes! Then I looked at my already cannibalised WS19's and these delivered the tube sockets and wave band switch. Unfortunately, the sockets turned out to be too large. I will take out wiring as well, in order to wire my paraset with old textile covered wires. Capacitors will come out also.

Also: the top and bottom sides are bended 90 degrees.

Looks already great, doesn't it?

Still puzzling about some things, like the correct moment to put paint and text on the front panel. And how to make a slow motion dial drive with a minimum effort. How to mount the reception coil I have, in a professional manner. Still looking for a 36 H choke or something useful. The key can wait...... Ah, what a wonderful hobby!

For now I have to wait until a shipment from U.K. comes in. I ordered some material to make water slide transfers on my laser printer. I'll have to wait and see if that brings a satisfying result.

Take off the wiring and the mounting struts, heat the core and wipe off the remaining wax.

A Dremel power tool with a small grinding disk is very helpful for this job. You can grind away the rivets from the inside without damaging the core.

So I decided to look into my old Meccano box (Dutch imitation Meccano, that is) and make a simple coil winding machine from what I could find in there.

On one of the sites mentioned in the Link section, a book is shown, called "Building a coil winding machine". I obtained the book and set it aside as a project for the near future. Because once you have such a machine.........

Make three square's of PVC, a little larger than the core. Clamp them together and drill a 3 mm hole in the centre, through the three squares.

Glue two squares together and mill (with help of the Dremel and a dentists milling bit) a nut-sized hole in the upper plate. Make it tight and squeeze the brass nut in with a hot soldering iron. Caution: we don't want the nut to sink deeper than that one square!

Yes, the PVC is a bit dirty but it will come out fine in the end - wait and see!

Put it in a lathe and start cutting away the obsolete material.

The bottom part (close to the clamp) must be about 1 mm wider than the core outside measure. This equals one layer of PVC.

The lower part, two layers of PVC is resized to fit the inside of the core.

If you don't have a lathe, an electric drill, a sanding dish and a file can do the trick as well.

I am not quite happy with the coil itself. It is not quite what I had in mind. Perhaps I will make another one.

I will press the coil on the pedestal with a piece of tape between the two. I have already an idea how to join the two together in the final version.

Yes, I will paint the white thing brown!

As I said, after printing, things are prepared to apply the transfers. One needs some tools like tweezers, knives, pointy things, cloth for dipping water, q-tips, a bowl of hand warm water. The hotter the water is, the faster the transfers separate from the sheet. You don't want that!

Did you notice the wooden side skirts I attached? Those put the front panel flat on the workspace, in spite of all the components and bolts, already in place. Later I will turn them around, when mounting components, to prevent the painted front to be scratched.

This transfer material comes in two types: for (colour) inkjet printers and (colour) laser printers. Alan,  G3WXI, put me on the track for this supplier in the USA. Click here to go there. It has training videos that are helpful.

A lady in the UK also sells the material, there one can buy one or two sheets. Search on eBay for item: 310120743711
Her website: www.sarastexturecrafts.com.

Another problem arose. I used dishwashing detergent to break the water viscosity and to provide the means of placing the transfers easily. Went well. But..... water and soap stains remained.

Which brings me to the next advice: if your water tap gives water with a lot of calcium, don't use it for the transfers! Buy a bottle of drinking water, or demineralised water, used for filling car batteries (NOT ACID!!)

OK, so one decides to wash away the soap remains under the tap. Great, all the soap ran off easily. Closer inspection learned that the transfers went along, down the drain. I could start all over again!

The good news: the second time I got it better and there were no water stains. It was a lot more difficult to position the transfers in the right place, though.

So I made a little tool in which I made a small cavity that could fit the base of the rivet. On top comes a washer. Than the socket, than the front plate. Of course you need six more hands to keep everything in place. A wife would come in handy.

On this photo you will see the rivets and the tool I made to keep the rivets head, round. It is just a peace of steel where I drilled a hole in, big enough to fit the head.

With this punch, a hammer and a substantial punch the rivet is in its place, wearing a round hat.

This is really looking good!

The dial is not the right one, yet. But the rest looks fine to me! Click on the photo to see a bigger one.

For the time being, the serial number plate is a transfer.

The first weld!

In the old days they put small peaces of rubber tubing over the end but I don't have those.

This is how I did it: I wrapped a small strip of black textile insulating tape around the wire, 6 mm or so from the end.

Clean as a whistle!

When used in the set, this looks really authentic and won't get fuzzy!!

One has to be very careful in reading the drawing. Measurements are sometimes easy to misinterpret because of the given reference point.

After sawing, milling, drilling and tapping I had a crystal clear body for the key.

It is not to my liking, so I will construct a better tool, to press a proper curve for a 3 mm axle. This needs some more experimenting.

More photo's will be put here as the project continues. The contact points have to be made as well as the knob.

To be continued....

I put the sticker on the bottom, to keep the reference for future need. I wrapped a few layers of black textile insulating tape around the core to give it an "old" look.

But, it takes more...

 How to obtain that? Easy, once you know it. I went to a shop that sells old materials for oil-painters. Not the ones that paint  your house, but the art-guys.

 The shop sold me a paper bag with shellac flakes and a bottle with 90 % alcohol. The recipe is simple: put the flakes in a bottle: one half flakes and one half alcohol. Leave it for a couple of days so the flakes can solve. Shake the bottle every now and then. It took two weeks and now I have a nice, thick solution.

Warning: if any alcohol is left over, don't drink it!

I riveted the solder eyes on the pcb. Underneath I removed the copper sheet around the rivets.

The last thing to do is to make the base plate.

To be continued....

That is a part, hard to find. After several request on the Internet, which had poor results, Alan,  G3WXI, sent me a brass dial.

It was corroded but after several hours with abrasive, polish and a dirty kitchen sink I had a nice dial.

The corrosion had left an impression like the object had been sand-blasted. Suits me fine!

I sprayed it with several layers of varnish and waited not long enough to let it dry. After mounting the knob and taking it off again, the strange stain in the centre remained. No problem, though.

Then the drive plate had to be made. With jigsaw I took a circle out of a brass sheet. The idea was to make it perfectly round, later, on the lathe.

Watch the hole: too small to give a stable support in the lathe. I made this wider and gave it a tight fit for a M10 bolt using a reamer.

To be continued.....

Mind you, I did it the wrong way around. The proper order to make such a base is:

- drill the holes in the Paraset front;
- mark them on a wide enough piece of metal (the future base);
- draw the shape of the base on that piece, based
  on the hole-markings;
- make the base;
- assemble base and choke;
- apply the pcb and the tape;
- paint the assembly.

As long as the pcb is not mounted and the choke is not painted, you can clamp it in a vise to bend the choke's mounting lashes around the base, that's why.

Then take your saw and files and start working....

I decided to make the slomo shaft, slightly different than is on the drawings. This way, it is less work and the chance to be successful is somewhat larger. You will see what I mean further on.

So, here I drill a 2,4 mm hole, about 30 mm deep, to cut 3 mm thread.

I enlarged the 2,4 mm hole to 3 mm to fit a 3mm bolt.

This way I do not need to turn down a peace of the shaft and cut thread in order to make thread M3. Since the shaft is made of brass, snapping off can easily happen.

After cutting they need to be turned down to get them round and in the proper size.

In order to be able to mount them in the lathe, I used some pieces from the junk box to make a solid axle.

On the drawing you can see the part I altered.

The only thing left is to find proper washers to make the necessary spacing.

As you can see, I decided later to take some material from the top if the bushing, in order to reduce friction between the lower brass plate and the top of the bushing, in order to become a smoother action.

You can also see that the hole is off centre. That could have been 0,5 ~ 1 mm more........ Next time.

The brass I used, is 0,7 mm thick. So, between the little plates you would want 0,6 mm to properly clamp the big plate. Between the big plate and the dial you would want 0,8 mm, to keep the little plate free from the dial.

Hitting a washer with a hammer can make it a little flatter...

It works well. Next time, I need to make the hole and shaft a little tighter, though. Building Parasets is an on going process....