Its very greeeeeeeeen

[rszemeti]

No, not going to scan it. Not really interested in scanners, I leave that to the laser pointer kiddies.

I shall just keep it as a plaything, I'll get it properly collimated and play with it a bit more. I suspect I'll do a couple of cloud shots on a foggy night and then get bored.

I might look for another colour to go with it. I have some 1.2W blue diodes, but can't really be bothered to play with them, as they fall into the same category as laser pointers really.

Keeping an eye out for a dye laser, or a copper bromide maybe ... something a "bit different" anyway. CO2 doesnt really excite me, had big CO2's in the past, and big YAGs, so going to hunt down a visible laser or two ... needs to be 5W+ really, below that is kinda boring, unless its really amusing technology, maybe a Ti Sapphire? Same goes for Argons ... they are sort of amusing, had a few with an intra-cavity prism for line selection, they seem to work much better than the external prisms, get a bit more power out of them, but they are weak compared to a decent 532nm.

I suppose a homebrew CuBr might be fun, if I could find a decent length of ceramic bore.

I miss the old alt.lasers newsgroup .. there were some seriously knowledgeable people on there, the forums these days seem to be focussed on projectors and disco effects made with cheap chinese modules, which really bores me. There used to be a lot more experimentation going on, people making odd-ball lasers out of coke cans and HV supplies. No idea where all that has gone now .. maybe people don't play with lasers any more like they used to?

[dsli_jon]

Well, I was trying to keep it simple for the laser-pointer kiddies, if you start talking about Q switched as pulses, they expect to see the beam going on and off,

Hehe... well, you could have *really* threw them for a loop, and discussed it all in 'Quazi-CW'...

I guess anything better than about 20 uS is good?

Umm, you mean Ω's.... ...and, really, anything north of 500 Ω is 'technically ok' - Ideally, you want to keep it north of 1K Ω, in the tank...
anything south of 700, after you've changed-out the water, completely, it's time for a new DI-cartridge, imo...

..Anyhoo, cheers to the overkill..
j

No idea where all that has gone now .. maybe people don't play with lasers any more like they used to?

..enter the 'PROCheapClonedCrap'... ..mostly...

[rszemeti]

No, I mean uS, micro Siemens.

Resistance is measured in ohms, conductance in Siemens.

To be abolutely correct, we are talking about resistivity and conductivity, which are measured on ohm-metres and an Siemens per metre, so i should have written uS m^-1

The difference between Ohms and Ohm-metres is of course the resistance in Ohms woudl vary depending on how big the electodes where, and how close together they were. The resitivity in Ohm-metres (or conductivity in Siemens) does not vary with the size of electrodes, as the calculation takes that into account. Its better to quote the resistivity or conductance rather than the actual resistance, or you have to mention how big the electrodes where and how far apart, etc etc.

My conductivity tester reads is in Siemens, most Yags I have had throw a water conductivity error at around 50 uSm^-1, if I remember right, and the ones without a conductivity test become hard to light around that figure ... I guess it depends how much "oomph" there is in the igniter circuit.

No idea how good the LS igniter is, I guess we will see. I have a bag of DI crystals somewhere, I can always repack a tube, don't fancy spending money on the cartridges, I bet they selll for "medical" money.

[rszemeti]

Troll

One who posts a deliberately provocative message to a newsgroup or message board with the intention of causing maximum disruption and argument

For instance: Deliberately claiming to having performed absurdly dangerous acts to a safety conscious community in order to provoke a big drama; for an example just read the first part of this thread.

Bwaahahaha.

Hypocrite

Someone who dives in feet first, without considering it might be humour, wanders around the place telling people how to run their lives, and aparrently, has not even read his own signature.

Seriously, you have an amusing signature about "The Health and Safety Act 1971" "Recklessly interfering with Darwin’s natural selection process" and then go off on a health and safety rant? Kindly excuse me when I fail to take you seriously.

By the way, there is no such thing as the "The Health and Safety Act 1971" .. there is the "The Health and Safety At Work Act, 1974" .. perhaps you meant that?

[jooopy]

Child Protective Services

Wiki-(CPS) is the name of a governmental agency in many states of the United States that responds to reports of child abuse or neglect.

[rszemeti]

Bwahahaha

I just looked up Humourless Retard on wikipedia and it said "see Texan" ??

[dsli_jon]

No, I mean uS, micro Siemens.

Ah, I C... I read it like you were trying to say µSeconds - which - obviously, would throw a

RE: the uS - interesting way of looking at it... never really thought of it that way, since all the LS service manuals / all training I'd ever gotten teach checking the resistivity of the water...but certainly you can 'maintain it' via checking conductivity.. then, yes, in that case, you'd want a lower number, not higher, as with the Ω... either way, low-resistivity, to the cavity, or high-conductance, to the cavity, via the water = bad.

I have a bag of DI crystals somewhere, I can always repack a tube, don't fancy spending money on the cartridges, I bet they selll for "medical" money.

Mmm, it'll be a 'fun-project' repacking a hard-glued cart... I think you'd be better off just 'making-up' a new one, what, with charcoal and silica and nylon-fittings being dirt-cheap... But, cost-wise, I get the complete 'PM kits', for about $300., which includes a brand-new lamp, DI-filter (large-cartridge style) particle-filter, and 2 new gold-plated 'lamp contact-baskets'... that's a pretty-good deal.. hope no 'LS Doctors' read this and riot on their service-guy...

cheers...
j

[rszemeti]

$300, thats excellent value. You might have to PM me where form

DI cartridges are easy enough to re-pack or make, couple os stainless mesh filters, some plastic pipe, end caps and DI crystals. We found that they use DI crystals by the bucket full in the EDM / wire cutting industry, I think it was about $2 / lb when we got a sack or two, if you can get the carts apart, its easy enough to re-pack them. When filling hte tanks on big CO2 systems, its usefull to have a decent sized DI pack, with hose-pipe fittings to process the tap water through.

I suspect I will not need one though, as when we've done a couple of sky shots I'll probably get bored and stick it in a corner as a rainy day toy.

I have a couple of things I want to try, one is a foggy-ish evening, have it pointing straight up, go a mile or so away turn it on and see if its visible.

Other thing I want to try is a gloud shot, clear air, high cloud. I have a 10" telescope mirror, about 1300mm fl, with a lambda/10 surface quality and a suitable expander. Obviously the beam at ground level would be 10" wide, and thus almost invisible side on .. so low down, it would be rather pants. However, 10,000 feet up, I hope to get a much smaller spot than I would from a conventional 10mm output lens ... I recon it might make a nice bright spot on a cloud. I might need to build a tube for it, as I dont fancy the stray refelctions that would be bouncing around off that one.

I'd also like to try it pointing upwards when its snowing, a wide beam might be good for that .. I reckon that might look pretty kewl.

I'll probably get bored with it after that.

[dsli_jon]

$300, thats excellent value. You might have to PM me where form

Yep, 'tis a good 'bundle' ..and, 'from' right here in crazy-ol' Caliwarmya...

I suspect I will not need one though, as when we've done a couple of sky shots I'll probably get bored and stick it in a corner as a rainy day toy.

I predict, not... here's some 'inspiration' for ya...

I have a couple of things I want to try, one is a foggy-ish evening, have it pointing straight up, go a mile or so away turn it on and see if its visible.

Suggestion... try, like, *several* miles... http://a1.ec-images.myspacecdn.com/i...dabb101d/l.jpg I think you'll be pleased with the results...

But - I'm sure you already know, but I'm still gonna say-it - respect the airspace-laws, there / keep a sharp eye-out / radio / cel contact with your 'e-stopper', eh? Nothin like a nasty fine to spoil yer fun...

Other thing I want to try is a gloud shot...I recon it might make a nice bright spot on a cloud.

I reckon you're right... http://a1.ec-images.myspacecdn.com/i...ca474387/l.jpg

I'd also like to try it pointing upwards when its snowing, a wide beam might be good for that .. I reckon that might look pretty kewl.

You're rather good at that 'reckoning' thing... http://www.youtube.com/watch?v=LuxL1pfUAI4 ..now, imagine the 20-30W...

I'll probably get bored with it after that.

Again, I say, we'll make a 'scanning-convert' out of ya, yet..
http://a3.ec-images.myspacecdn.com/i...4fe2e7fe/l.jpg
http://www.youtube.com/dslasers#p/c/.../5/3bRUSP5YHXw
http://www.youtube.com/dslasers#p/c/.../6/HBxRFek-qNs

..bored yet?

ciao
j

[rszemeti]

heh, those are pretty kewl I admit.

I'd crap myself before trying that building shot with the snow ... so many ways to go wrong there .. rig moves, person comes out of building, un-noticed window in building where the Janitor gets an eyeful .. needs a lot of prep work.

Where I am there are (as best I can find out) no regulations about pointing class 4 lasers at clouds ... you can pretty much do what you want .. the obvious flip-side is if you do go and cause a plane problem, you are so deep in the crap, its not true. You can get a temporary danger area on NOTAMS, but, its a lot of hassle, for a bit of playing around, you are simply better off choosing a night with a bit of cloud, and making damn sure there are no planes. Easy enough, as I'm in the middle of nowhere and you can hear them.

"UP" is a good angle, not a lot can go wrong with a few sensible precautions.

The plus side to scaning is the public reaction, not that I give a monkeys chuff what the locals think, but if its scanned they are more likely to go "ooh look, pepsi advert" or whatever, if its just a beam, some local twonk with an IQ lower than his shoe size will probably be on the phone to the feds telling them Al Queda are shooting down air liners / satellites / moons ... or the aliens have landed .. so maybe scanning has its advantages.

FWIW, my usual procedure is a visual check with the red aiming laser, make sure its going where I think it is, then its goggles on, a test shot at 50mw, make sure it really is, power up, goggle check, hit the go pedal and grin. If I get someone else to press the pedal, they stand well behind the beast, goggled up, and being the trusting soul that I am, If its for an outdoor shot, looking back, I dont go anywhere near the danger zone until they have come out of the shed and well away from the pedal, I don't trust anyone! My other hobby involves lots of high velocity lead, so its just like range safety ... no one goes forward until the range is safe.

Trouble with these things is, a single stray splash of light will do permanent damage. Milliseconds is all it takes, no second chances, and do not stare into beam with remaiing eye


Respect there for doing that stuff in cities. I would be crapping myself ... out here in the sticks, few sensible precautions, not a whole lot can go wrong. In a city? jeez .. one false move and you are looking at lawsuits. Infact, even *without* screw up I'm sure some twonk will be on the phone "my dog just got blinded, get me a lawyer" ... "i was driving along and I got this flash of blue light" "but its a green laser" .. "err, yeah .. green light" etc etc .. not my cup of tea, I like a nice peaceful life