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Misc. Neon Stuff
>> The line Transco carries is called "Blox Out." I called them today, and
they said they've carried it for quite some time. I tried to order some,
and they referred me to one of their distributors. I tried a total of 3
distributors (2 are places I have credit accounts) and neither had
the foggiest idea what I was talking about. <<
Doesn't surprise me. I stopped by the Transco booth at the Show East Conv.
and basically told the Rep. (not Morgan) that I've tried for years to use
Transco's products but couldn't get them. This was before they were in The
States. Basically, I said "Don't bother selling the stuff if you can't get
it". If you have a problem with availability talk to Morgan Crook. He is one
of their Reps. and I'm sure he will be glad to help you. Tell him you talked
to ME. I am curious to try the stuff as well.
>> Evidence of the overprocess was simply a slight ring of soot on the
ceramic collar around the hole. When it occurs, it can be _completly_ removed
by admitting about 3 torr of air and re-bombing a few seconds. When it occurs,
it can be completly_ removed by admitting about 3 torr of air and re-bombing a
few seconds.<<
Sounds like something reactive with atmosphere (ie. oxy, etc.) Could be
remnants of a "gettering compound". For those who don't know. A getter is a
chemical that activates at high temperature and is highly reactive with any
molecular products in the vicinity. Some electrode manufacturers use this as
a final purification method. There is much discussion on the validity of this
but it is widely uses in other vacuum fields ( like the plasma physics guys ).
I use Voltarc electrodes for hard to pump repairs because their getter
compound is very good (IMHO) at blasting out any residual sodium, etc. left in
the tube.
>> Like if never even happened. It can happen even with underprocessed
trodes. The only clue I have is the way is dissappears with re-heating.I don't
always get this soot. It seems to happen during the final heating at 500ma.
I have been taking some notes to try and indentify the phenomenon, and it
_seems_ to get worse at reduced pressures. <<
The reason it may get worse at reduced pressures is because there is nothing
to react with. Whatever it is apparentl yneeds molecules to aid in the
process of removal. As long as it is not causing any staining or such, it
should stay relatively inert with the inert gas added. Watch for signs of
problems with merc. tubes. As long as the merc. is not reacting with it I
wouldn't worry about it.
>> when temp. crayon has shifted color, <<
I used to use one of those as well. I switched to the paint-on variety.
Great stuff, though. I have 3 temperatures. One is a warning indicator that
"you are about to MELT the glass now!" for small diameter/tight bend stuff.
Another is "you are ALMOST up to temp" (don't use that one as much as I
thought I would).
It is about 50 degrees shy of the 425F. final temp. indicator.
>> >one art installation in a home is complaining that their tv remote
>control (25-40KHz infrared) doesn't work at all when the neon (RF <<
Like Kenny pointed out, this frequency is far removed from infra-red ( which
is 10 to the 12 power smaller in wavelength ). My brother, Dave,
experimented with a lot of solid states ( we call him Mr. 12Volt ). He
reported the same problem you described and I have also hear of similar
reports. I just assumed that the problem was those fine emission specta lines
associated with neon gas in the red region of the spectrum acting as a jamming
frequency. Never did persue it much further, though. Don't watch TV, don't
have a remote to test it with. I work in entertainment, why would I want to
come home and watch it? <g.>. I kinda forgot about it and put it on the back
burner of research priorities. Let me know what you find. I am curious.
>> better yet refer them to your customer service line that plays music on
hold all day <<
As Thomas Edison once said "NEON, wish I'd thought of that".
>> .Re: the 12000v transformer. Don't remember, is it wired as a center
tapped circuit and is the transformer center tapped? If you are able to break
the circuit in a fairly close to equal manner (in terms of transformer output)
running an extra line from this center point to the transformer's ground can
help significantly. The transformer then becomes two 6000v circuits which
have lower peaks an therefore less interference - not to mentioon less wear on
the transformer. <<
Sorry to step on toes, Kenny, (especially after the compliments) but I have a
continuing argument on this one and some other install "misconceptions". While
you are right about splitting the transformers into two, (all transformers
above 7,500V are center tapped as per NEC regs. req. no higher voltage than
7,500V above/below ground) are actually 2 smaller transformers "back to back"
I don't think that it would help the problem that is under discussion. The
main thing remember is that ground is only a reference. Since the transformer
winding is tapped at the primary for center ground, the secondary is already
referenced as far as it's AC swing relative to ground is concerned. I use this
aspect to eliminate HV interactions between other transformer secondaries.
What you have to remember is that while one of those two smaller transformers
are going positive (with respect to time ) the other half is going negative
(relative to ground ). The only thing that center point grounding the
secondary would do is reference the "floating point" for which connection
(tube) is actually at 0V. potential. This is useful when you have long runs of
GTO since you can put them at ground potential and not have the usual HV
interaction with ground. It does NOT cause the opposing HV leads coming from
the transformer to be ANY less voltage with respect to EACH OTHER and hence,
does NOT really lessen the HV interaction between the two. On a system where
there is no center tap connection to the secondary you simply have a
"self-balancing" condition where the 0V. potential is allowed to "find it's
own center". I think that this method is easier on a transformer because it
would eliminate a potential imbalance (due to slight loading differences)
between the secondaries IMHO. Again, a lot of what I learn is stolen from
other technologies and there is an uncanny relationship between the audio
balanced and unbalanced scenario and the neon transformer one. Understanding
of one helps me with the other (both of which are confusing to most ).
>> Hmm, this statement caught my attention. Do their desktop phones also use
110VAC to power on-board accessories like integrated answering machines or the
like?
If so, you might want to grab an o'scope and see if there's obvious noise
that's getting in to the phone this way instead of through the phone lines
themselves. It's possible the portable phone is better built than the desktop
units and has better filters for noise entering via this path. Of course,
this would only apply if the noise is something other than 60hz stuff <<
This is a good suggestion if you have an O-scope handy. I have a couple in
my shop for just such reason. Like the subject title of my magazine article
says "I work with things you can't see". Well, here is a way to do just that.
Also, the fact that it doesn't bother the portables (which should be MORE
succeptable to problems) also points to either line noise or the magnetic
induction I mentioned before. Also, it could be a combination of both. The
magnetic induction could be showing up on the AC line! It takes some good
detective work, but the answer IS there. At least if you know WHAT is causing
it, that is 3/4 of the ball game.
Did I say long-winded? As Chris says, "don't get him started".
E-mail from: Tom Biebel, 15-Dec-1995
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