73, de N2HTT

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Snowy day, new glue.

Posted: 24 Jan 2016 03:07 PM PST
http://n2htt.net/2016/01/24/snowy-day-new-glue/


Weve had the first snow of 2016, and it was a doozy. Winter Storm Jonas, as
it was named in the media, was a noreaster 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.
Mast still up after Jonas

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 unexpectedÂ*down time seemed ideal. Unfortunately, I was not as
well prepared as I thought. Ive 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!Â*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 cant 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 listeningÂ*with the crystal receiver
quite a bit in the evenings, I thought it might be a candidate for some
improvements.
Attached to the antenna (new diode)

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
reallyÂ*have been listening toÂ*broadcast AMÂ*with this radio. You can
actually DX broadcast AM with it I heard WFEDÂ*AM (1500 kHz) from
Washington DC quite clearly the other evening. Its 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. ItÂ*was one of those as seen on TV things; we dont 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 someÂ*on Amazon. Intrigued, I asked for a link on Amazon, and
she responded by saying shed 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 mixedÂ*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; Im completely paranoid about cataracts.

The first task I tackled was to mount an SO-239 socket on the back of the
receivers 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 jointÂ*would have been

messy
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 cant 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 toÂ*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 afterÂ*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.Â*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.
SO-239 attached with UV glue. (Glue is fluorescing)

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.
Front panel attached with UV glue (Fluorescing)

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 arent all the
necessary. But Im standing by the UV goggles you cant 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
No more alligator clips. (Well, only one.)

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 childrens 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 themÂ*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.
Frozen charlotte, guarding the entrance to the coil.

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.
Crystal set, decorated.

Get this glue away from me, before I really hurt myself.

73,

de N2HTT