Conducting Bench Top Material
Steve Rooke wrote:
Wasn't life so much easier with valves (tubes)...
Nostalgia?
Valves (tubes) warmer in close proximity, yes. Global warming should
make that, on average, less helpful.
In the 60's listening to rock music, I could look at the final tubes in
a dark room and see the purple glow inside dance with the music.
Anyone else?
Solid state amps just can't do that. Way cool. I never tried it with
cannabis, but probably even better.
Other than that memory, and certain trade-offs at big Rf power, I'll say
I no longer encourage the glowing bulbs for most things.
And at least I can drop a transistor on the floor without too much damage ;-)
Robert G8RPI.
--- On Thu, 28/1/10, Rex rexa@sonic.net wrote:
From: Rex rexa@sonic.net
Subject: Re: [time-nuts] Conducting Bench Top Material
To: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Date: Thursday, 28 January, 2010, 5:50
Steve Rooke wrote:
Wasn't life so much easier with valves (tubes)...
Nostalgia?
Valves (tubes) warmer in close proximity, yes. Global warming should make that, on average, less helpful.
In the 60's listening to rock music, I could look at the final tubes in a dark room and see the purple glow inside dance with the music.
Anyone else?
Solid state amps just can't do that. Way cool. I never tried it with cannabis, but probably even better.
Other than that memory, and certain trade-offs at big Rf power, I'll say I no longer encourage the glowing bulbs for most things.
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And no-one ever invented complimentary N channel and P channel valves
(tubes).
And they had a service life of 5000 hours and they stoppd working
properly.
On 28/01/2010, at 6:51 PM, Robert Atkinson wrote:
And at least I can drop a transistor on the floor without too much
damage ;-)
Robert G8RPI.
--- On Thu, 28/1/10, Rex rexa@sonic.net wrote:
From: Rex rexa@sonic.net
Subject: Re: [time-nuts] Conducting Bench Top Material
To: "Discussion of precise time and frequency measurement" <time-
nuts@febo.com>
Date: Thursday, 28 January, 2010, 5:50
Steve Rooke wrote:
Wasn't life so much easier with valves (tubes)...
Nostalgia?
Valves (tubes) warmer in close proximity, yes. Global warming
should make that, on average, less helpful.
In the 60's listening to rock music, I could look at the final
tubes in a dark room and see the purple glow inside dance with the
music.
Anyone else?
Solid state amps just can't do that. Way cool. I never tried it
with cannabis, but probably even better.
Other than that memory, and certain trade-offs at big Rf power,
I'll say I no longer encourage the glowing bulbs for most things.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/
time-nuts
and follow the instructions there.
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time-nuts
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Warning: Way OT
When the vacuum tube was born, there were half as many people on
this planet, and global climate change wasn't a problem. Very few
people will talk about populution. It's as if there was a blind
spot in the brain. Maybe there's no intelligent life in the
Universe because all life evolves with similar selection pressures.
Once technology removes natural predators (or stops world wars with
the atomic bomb), population heads for the sky until the big die-off.
If other people don't have a problem with having four kids, I have
no problem with using vacuum tubes and Edison bulbs.
All in my humble opinion, of course.
Bill Hawkins
-----Original Message-----
From: Rex
Sent: Wednesday, January 27, 2010 11:50 PM
Steve Rooke wrote:
Wasn't life so much easier with valves (tubes)...
Nostalgia?
Valves (tubes) warmer in close proximity, yes. Global warming should
make that, on average, less helpful.
........
glowing bulbs
Other than that memory, and certain trade-offs at big Rf power, I'll say
I no longer encourage the glowing bulbs for most things.
In message 924780D899C84029950F3D9CAEE28054@cyrus, "Bill Hawkins" writes:
When the vacuum tube was born, there were half as many people on
this planet, and global climate change wasn't a problem. Very few
people will talk about populution. It's as if there was a blind
spot in the brain.
No, the blind spot is making a big issue out of population control
in countries where the environmental footprint per person is virtually
nill essential zero, in order to obscure the fact that approx 1% of
the population of the planet is responsible for 99.99% of our
problems, environmental or otherwise.
Poul-Henning
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
Hi
If we ever go back to tubes we're going to have a bunch of tech's knocked out on the floor. Nobody has a clue about high voltage any more. You had to have a good respect for it on a tube circuit or you got in big trouble.
Bob
On Jan 27, 2010, at 9:23 PM, Steve Rooke wrote:
Hi
If you are manually loading up a wire bonder with conventional CMOS chips, ESD damage is a very real thing. You can haul the chip over to a SEM and actually take pictures of he craters you blast in it. Very cool pictures. No cat's, carpets, or Windhurst machines needed. Just normal operators with missing wrist straps will do the trick quite nicely.
Bob
On Jan 26, 2010, at 2:21 AM, d.seiter@comcast.net wrote:
Back about 1981, we had piles of 6502s, etc and decide to some "antistatic testing". We put a 40pin ZIF socket into a VIC-20, and then set about trying to fry the uP using carpet, a cat, car seats, etc. The DUT was then put back into the VIC and series of tests run to verify operation. I don't think we ever had a failure. Of course, there may have been some hiding that we missed, but all the static damage I've seen has been pretty severe.
That said, I always use a wrist strap and mat if I'm working on something I don't want to break further.
-Dave
----- Original Message -----
From: "Charles P. Steinmetz" charles_steinmetz@lavabit.com
To: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Sent: Monday, January 25, 2010 11:27:11 AM GMT -07:00 US/Canada Mountain
Subject: Re: [time-nuts] Conducting Bench Top Material
Bruce wrote:
Although over the years the non-conductive top has been an asset in
avoiding short circuits, etc., I am concerned about static discharges when
handling modern semiconductors. Would it make sense to spray the Masonite
with a weak copper sulphate or similar solution so as to make the masonite
slightly conductive, but not so conductive that 155 VAC connections
could not
safely rest upon it? Is there a better-suited material that could be used
to replace the Masonite?
I notice that many folks who have contributed on this thread use
anti-static benchtops, but I have never found it necessary (and I try
to keep the RH in my house under 45% -- it is generally 20% or less
in the winter). I've been fooling with static-sensitive parts for 35
years and haven't lost one to static yet. With that perspective, my
preferred benchtop is white Formica with a very, very slightly
pebbled surface. Very durable, including to molten solder, and small
parts show up well. I use rubberized "gunsmith" mats for preventing
scratches to delicate workpieces (these happen to be anti-static, but
that is not why I have them).
Other bench thoughts:
Bench depth is very important. I sometimes work on equipment that is
more than 24" deep, so I want at least 30" of clear space in front of
any obstructions (power strips, Variac, test equipment,
whatever). In the past, I used a "flying bridge" over the rear 18"
of a 48"-deep bench to elevate the test equipment, which worked very
well. Now I use 24" deep adjustable wire-rack shelving units behind
a 30" benchtop (As others have pointed out, you can do the same with
equipment racks -- I'm not a fan of rack-mounting test equipment
unless the racks are anchored and everything is on slides, which I
was not prepared to do). I don't have enough shop real estate to
have a permanent access aisle behind the test equipment, so the bench
and racks have large (5") locking polyurethane wheels and can be
pulled out relatively easily for reconfiguration. This provides
plenty of stability for electronic projects, but you wouldn't want to
mount a big vise on the bench and try to bend 1" rebar. For that, I
have a separate metalworking shop.
Bench height is also important. I prefer a tall bench, suited to
working standing or sitting on an ergonomic stool, so my bench top is
44" above the floor -- a bit below my standing elbow height.
Finally, one can never have too many power outlets, or too much
light, in a workshop. Lighting should be arranged so that it doesn't
cause specular reflections from the workpiece or the faces of test equipment.
Best regards,
Charles
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--
Steve Rooke - ZL3TUV & G8KVD
A man with one clock knows what time it is;
A man with two clocks is never quite sure.
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2010/1/28 Bill Hawkins bill@iaxs.net:
Warning: Way OT
When the vacuum tube was born, there were half as many people on
this planet, and global climate change wasn't a problem. Very few
people will talk about populution. It's as if there was a blind
spot in the brain. Maybe there's no intelligent life in the
Universe because all life evolves with similar selection pressures.
Once technology removes natural predators (or stops world wars with
the atomic bomb), population heads for the sky until the big die-off.
If other people don't have a problem with having four kids, I have
no problem with using vacuum tubes and Edison bulbs.
All in my humble opinion, of course.
True, but I can never recall having a problem with ESD with them
(which was the current topic of the thread).
Steve
Steve Rooke - ZL3TUV & G8KVD
A man with one clock knows what time it is;
A man with two clocks is never quite sure.
2010/1/28 Rex rexa@sonic.net:
Steve Rooke wrote:
Wasn't life so much easier with valves (tubes)...
Nostalgia?
Nostalgia ain't what it used to be!
Valves (tubes) warmer in close proximity, yes. Global warming should make
that, on average, less helpful.
And we heated our houses less.
In the 60's listening to rock music, I could look at the final tubes in a
dark room and see the purple glow inside dance with the music.
Anyone else?
Way, way back I was listening in the background to an old Teak amp one
day when I thought that it sounded a bit distorted. Went over to look
at the chassis and saw one of the valves in the output stage with it's
anode glowing red! Hmmm, seems it was conducting just a little more
than it was supposed to do due to a biasing component failure. A
couple of minutes later and some work with a soldering iron and the
sound was fine again. That chassis went on forever on that same valve.
Solid state amps just can't do that. Way cool. I never tried it with
cannabis, but probably even better.
They soon go legs up if you apply too much voltage or current which
valves would just shrug off.
Other than that memory, and certain trade-offs at big Rf power, I'll say I
no longer encourage the glowing bulbs for most things.
They certainly still held their own in high power RF stages but I
wouldn't go out of my way to build something out of them now.
As for conductive surfaces for benches and the like, RS Components
used to sell a static conducting matting by the square yard that you
could order. It was a yellow and about 1/8" thick flexible dense
rubberized material. We covered our benches and floor around our
workplaces and had the press-stud fittings riveted to them so you
could clip your earthing strap to it. It was very hard waring and
coped well with molten solder dripping onto it. I believe I still have
a sheet of it somewhere in the garage.
73
Steve
Steve Rooke - ZL3TUV & G8KVD
A man with one clock knows what time it is;
A man with two clocks is never quite sure.
2010/1/28 Neville Michie namichie@gmail.com:
And no-one ever invented complimentary N channel and P channel valves
(tubes).
True but they did come up with a lot of designs involving multiple
grids etc which allowed a single valve to perform more complex
functions. Remember the old magic-eye indicators, triodes and pentodes
in the same envelope, mixers, etc.
And they had a service life of 5000 hours and they stoppd working properly.
And they were easy to fault-find, and replacement was a breeze.
I'm too far off topic now, sorry to hi-jack the thread.
Steve
Steve Rooke - ZL3TUV & G8KVD
A man with one clock knows what time it is;
A man with two clocks is never quite sure.
2010/1/29 Bob Camp lists@cq.nu:
If we ever go back to tubes we're going to have a bunch of tech's knocked out on the floor. Nobody has a clue about high voltage any more. You had to have a good respect for it on a tube circuit or you got in big trouble.
Remember the valves that used to have the grid at the top of the
envelope via a separate connection. That made it real easy to inject a
signal for tracing through the circuit, you just put your finger on it
and listened for mains hum at the speaker, for instance. hat was
alright till you found the valve that had an anode at the top...
That's going back a looong way.
Steve
Steve Rooke - ZL3TUV & G8KVD
A man with one clock knows what time it is;
A man with two clocks is never quite sure.