We’ve had the first snow of 2016, and it was a doozy. “Winter Storm Jonas“, as it was named in the media, was a nor’easter that roared up the east coast dropping record amounts of snow. We got our share, but being north of the storm track, not so much as to be catastrophic. A solid foot and a half of light powder, easily shoveled, no big deal really. Most importantly, even though we had some serious gusts, my new mast survived the storm handily, and my antenna is still in operation. Quite a relief, actually.
The arrival of the storm did have an impact on how we spent the weekend. Planned travel was cancelled, bread, milk, extra cat and dog food purchased, and we hunkered down to enjoy a quiet snowy weekend. Aside from occasional forays out to clean off the cars and the front steps, we were all left pretty much to our own devices. Ah, blissful unstructured time!
I had been planning to start the construction of my first space charge tube regen – the unexpected down time seemed ideal. Unfortunately, I was not as well prepared as I thought. I’ve decided to build this first version using a wooden “orange crate” construction, with thin slats and solid ends; spaces between the slats will accommodate the tube sockets. I figure this will give me some wiggle room as I lay out the circuits, without the profound emotional commitment demanded by making holes in an expensive aluminum chassis. Earlier in the week I had raided Home Depot to find nice oak slats and boards to build my crate, I was all ready to go.
The first step was to determine length of the end boards by laying out the slats and tube sockets. Oh drat! No sockets! I thought I had sufficient sockets left over from the construction of the W1TS Simple Transmitter, but as it turns out, the ceramic sockets I had left can’t be mounted easily between slats. The fiber kind, with a molded-in metallic ring is the type I need. Not a one remained.
Also, an inventory of variable caps came up short. The nice 150 pF one I had intended to use got drafted into my crystal receiver, and a rummage through my box of variable caps failed to turn up a replacement. I was seriously unprepared.
These shortcomings could be easily be remedied by a trip to eBay or Antique Radio Supply, but that would not help me this weekend. No, no regen this weekend.
There was plenty else to do, shovelling, operating, catching up on correspondence and paperwork, but I really was in the mood to play at the bench a bit as well. As I have been listening with the crystal receiver quite a bit in the evenings, I thought it might be a candidate for some improvements.
I have been using alligator clip leads for the antenna, ground, and headphone connections, and this is less than ideal. The signals would suddenly disappear as I jogged one lead or another – very makeshift. And I really have been listening to broadcast AM with this radio. You can actually DX broadcast AM with it – I heard WFED AM (1500 kHz) from Washington DC quite clearly the other evening. It’s sort of ironic, I never listen to broadcast AM with any of the “real” radios I own, but I am delighted to sit through auto parts store commercials when they are captured with just a coil and a diode.
Anyway, some improvements were definitely in order, and I just recently came into possession of an interesting new glue, that seemed to be ideal for the tasks at hand. In conversation a while back, my sister-in-law mentioned this new glue that she had heard about, but not tried yet. It is cured with UV light, sets in about 4 seconds, and has very high bond strength. It was one of those “as seen on TV” things; we don’t watch the right TV apparently, I had never heard of it, other than the stuff the dentist uses to make those costly repairs in your mouth.
She had bought some on Amazon. Intrigued, I asked for a link on Amazon, and she responded by saying she’d drop the glue off with me – I could try it and let her know how well it worked. Sounded good to me.
There are several varieties of this glue on Amazon, varying in price from about $10 – $20 for small tube, say about 100 ml, and an LED UV light used to set the glue. I think the brand I got was one of the $10 varieties. [Looks like the price has gone up a bit at the time of this writing]
Reading the package, I came away with a somewhat mixed impression, as the glue was described as “safe and non-toxic” but the instructions suggested gloves and goggles for handling, and a quick call to 911 before abandoning all hope should you accidentally ingest the stuff or get it in your eye. I decided to take the route of full protective gear, and I threw in a pair of UV goggles for good measure; I’m completely paranoid about cataracts.
The first task I tackled was to mount an SO-239 socket on the back of the receiver’s base board, thus eliminating one set of dodgy alligator clip leads. This would be tricky, because the edges of the board are not finished square, but have a very nice rounded edge. Not a good platform for traditional glue, because of the lack of contact area. I suspect that before UV glue, I would have tried hot glue, and the joint would have been
- not very strong, and would pop off the first time I connected a cable.
This is exactly the kind of challenge that UV glue excels at. It has almost no “sticktion” – you can’t put a dab down, place parts together, and let go. They will simply fall apart. But if you can hold the parts in place and hit it with the UV light, 3 to 4 seconds later, the stuff is rock hard. No tackiness at all. And perfectly clear. The glue is a fairly stiff gel, pretty much stays where you put it, but it will start to run under its own weight after a few seconds. It works best were you can use it to fill a void, by applying several applications and curing each one.
I laid down a bead of glue, held the connector in place, and zapped it. Wow, instantly rock hard. I filled the voids and zapped again. Immediately I had a connector that would stand up to attaching and removing the antenna cable, no problem. Pretty amazing. The glue cures clear and glossy, and is very hard to see, but it does fluoresce brightly under the UV light, so you can see clearly where it is.
Next, I wanted to add a socket for the 1/4 inch mono plug on the end of my high-Z headphones. I had scavenged such a socket from a ham fest special I am parting-out, but it was the kind that mounts in a 3/8 inch panel hole. No panel, what to do?
I made a little mini-panel out of single-sided PCB material, soldered to make an “L” shape with a second piece. Using the UV glue, I cemented the bottom of the “L” to the underside of the board, and then filled in the voids on both the top and bottom with additional glue passes. Again, rock solid, and luckily so, as considerable force is necessary to plug in or remove the phones. Another instant success.
By this point I had dispensed with the gloves. This stuff is easy to control using the applicator squeeze bottle; unless you expect to really have to tussle with the job at hand the gloves probably aren’t all the necessary. But I’m standing by the UV goggles – you can’t be too careful when your eyes are concerned.
So now with antenna screwed on, and headphones plugged in, everything was nice and solid and the rig was working FB. For some reason today, the strongest station I could hear was a French language call-in show. Quebec maybe? Endless hours of entertainment. But I was still not quite satisfied…
The receiver was working at top form, but it seemed to be lacking something. An aesthetic improvement perhaps? Armed with this amazing glue, I faced the rampant desire to glue more stuff to this radio.
My wife maintains an art studio on our property, she is primarily a painter, but creates puppet shows, writes and illustrates children’s books, and often creates small assemblages and sculptural works. Suffice it to say that her studio contains a wealth of odds and ends, and she is very generous with her materials when it comes to decorating radio projects. I think she feels that they are under-decorated in general, and will do what she can to correct that unfortunate state.
I asked for, and was graciously granted, two “frozen charlottes” from her collection. These small doll figurines date from the Victorian era, and were very popular toys for children. There are lots of internet material on them, you can look it up. Several years ago, when we first set up her studio, I had found a huge bunch of them from Germany on eBay, and given them to her as a “studio warming” gift. We might have the definitive collection in the northeast.
I thought that two charlottes, representing the etherial spirits, fixed at either end of the coil tube would not only be attractive, but enhance the operation of the receiver.
Unfortunately, I did not make quantitative, before and after measurements of signal strength, so this report needs to be considered anecdotal at best – however I swear those French-speaking callers were at least a half S-unit stronger after applying the figures. And I love the way it looks.
Get this glue away from me, before I really hurt myself.