Test Equipment Anonymous (TEA) group therapy thread

[beanflying]

Mmm in your place I would be flipping the R/O unit and spares and having a cheaper Laser as a result. Unless you start with really hard bore water or post dose the result you shouldn't generally drink it as water can be to pure for us Humans.

Either that or set up a system for drinking water and leave the R/O membrene out so just the Carbon and Sediment cartridge's without the pressure tanks too.

The sales pitch for the filtration system is that I can make all the pure water I need for the laser cooling system.  Apparently Bunnings "demineralised" water isn't as pure as would be best for the cooling.  Not sure about that but, hey.

There is a some fallacy about what water Lasers need.

1 None of the Laser Paths or the components making the beam have direct contact with or pass through the water when the beam is established so it doesn't matter.

2 Water in it's ultra pure forms doesn't stay that way it will suck minerals from anything it comes into contact with be it Metal and even some plastics and from the air.

So why the ultra pure water some claim is needed?

High Calcium or TDS in general will over time deposit out on the internal surfaces of the tube decreasing cooling efficiency (and it looks 'yucky'  ) Where I used to live topped out over 1000PPM in peak tourist season (bore water so always R/O for Coffee machines or death) where I now am 15km away is on a Rain based system and it is on average 100PPM (strip the chlorine out with basic filters and perfect for humans). Sydney tends to run higher than 100 due to the Limestone so decalcifying the water would be a good thing minimum, they are generally a Resin based filter and common in Coffee circles to tweak incoming water TDS.

Water that is more pure also as a general rule will never grow algae or miscellaneous bugs like Legionella and others but neither does tap water when treated before it gets to most homes. Over time even demin or distilled water will grow bugs and algae as it gets to a more 'natural state' by re ionizing itself.

Both of those reasons above are the real reason for ultra clean water as chemically treating the Tube later is the only way to clean any deposits or gunk from the inside.

If you decide to keep and plumb in the R/O then fit one of these to a Human drinking spout which might seem dumb adding minerals back in but it tastes WAY better in Tea and Coffee and is far less likely to give gut troubles due to the pH. Something like this https://www.gpawholefoods.com.au/buy/remineralisation-cartridge-in-line/RO-IN-REMIN?gclid=Cj0KCQjw7pKFBhDUARIsAFUoMDasFuDUF1m7f9qXex-UDjdHK_YO5rSfLdTyeMMRwlPr5-pRuPM5NRsaApo1EALw_wcB

[mnementh]

@mnem, That chain appears pretty close to the brake disc - a bit of grease screws the disc and pads for decent braking. Don't ask how...

Not a problem; going a different direction now. Maybe. Unless I can find a way to get another 5mm out of the axle. In which case, the chain will be another 5mm away from the rotor.

mnem
*drops back & punts*

[cyclin_al]

The classic british one was the Jaffa Cake
Went to the high court to decide if it was a biscuit (0 tax) or a cake (15-20% tax changed over th years). They decided this "cake" was a biscuit.

In point of fact they went to court to prove that they are cakes, as it's those that are zero rated; VAT is charged on biscuits (when covered in chocolate or similar).

The proof was that biscuits go soft when they go stale, and that cakes go hard. Since Jaffa Cakes go hard, they are by definition "cakes" and not "biscuits".

https://www.gov.uk/hmrc-internal-manuals/vat-food/vfood6260

Doh I'd been told the other way round and never thought to check.......

The idea that chocolate biscuits are a luxury and that chocolate cake is not, at least for tax purposes, is somewhat counter-intuitive.

According to the Chocolate Museum in Japan, chocolate is not necessarily a luxury and may be essential, dependent on the climate.
The Nordic Region (Norway and neighbours), Canada, Siberia, Sapporo and Antarctica are the places where they considered chocolate to be essential.
Consumption per capita appears to support that theory.  All those places have a cold and snowy season.
In the rest of Japan, chocolate was considered to be a luxury.  Then again, Sapporo and most of Hokkaido Island had 8 foot high snow banks when I visited....
 

[cyclin_al]

Alright boys, who's offering on this Agilent N1914A dual channel power meter? 
I'll put down $5.
https://www.ebay.com/itm/303953989765

woo woo, the seller want 1600$ 

even at 1$ it's probably too much.

No, $1 it is worth, the plastic frontpanel looks OK. So useful for a cosmetically-impaired unit.

well if you add shipping, I'm not so sure. it's 76$ over here

Don't forget that VAT might apply for some of our friends   

[cyclin_al]

[snip]
Princess Auto
[snip]

That is about the only remaining store in Canada that has truly great customer service.  Some of the products may be cheap, but no worries due to that amazing customer service. 

Their service is even better than Mountain Equipment Co-op, who used to set the standard in Canada.  Then again, that one was bought out, renamed to MEC and is no longer a co-op.  MEC was likely pillaged just to get the membership database 

[cyclin_al]

https://www.canadiantire.ca/en/pdp/mastercraft-5-shelf-metal-wood-rack-24-x-48-x-72-in-0686371p.html#srp

For the Canadians here who have test equipment storage problems:  25% off 24x48x72 shelving units at Canadian Tire.  I just checked with a measuring tape and that's deep enough to hold Tektronix 7000 and 500 series mainframe scopes and weight rated appropriate as well.  I just added one to my cart since I suddenly developed a Tek scope storage problem several weeks ago.

Interesting!  I always thought that Crappy Tire had the same prices across Canada.  Today I learned otherwise.  I looked at a bunch of stores in Quebec and Eastern Ontario; they all show full price.  Central or Southern Ontario stores have the sale price.   

[Robert763]

Mmm in your place I would be flipping the R/O unit and spares and having a cheaper Laser as a result. Unless you start with really hard bore water or post dose the result you shouldn't generally drink it as water can be to pure for us Humans.

Either that or set up a system for drinking water and leave the R/O membrene out so just the Carbon and Sediment cartridge's without the pressure tanks too.

The sales pitch for the filtration system is that I can make all the pure water I need for the laser cooling system.  Apparently Bunnings "demineralised" water isn't as pure as would be best for the cooling.  Not sure about that but, hey.

There is a some fallacy about what water Lasers need.

1 None of the Laser Paths or the components making the beam have direct contact with or pass through the water when the beam is established so it doesn't matter.

2 Water in it's ultra pure forms doesn't stay that way it will suck minerals from anything it comes into contact with be it Metal and even some plastics and from the air.

So why the ultra pure water some claim is needed?

High Calcium or TDS in general will over time deposit out on the internal surfaces of the tube decreasing cooling efficiency (and it looks 'yucky'  ) Where I used to live topped out over 1000PPM in peak tourist season (bore water so always R/O for Coffee machines or death) where I now am 15km away is on a Rain based system and it is on average 100PPM (strip the chlorine out with basic filters and perfect for humans). Sydney tends to run higher than 100 due to the Limestone so decalcifying the water would be a good thing minimum, they are generally a Resin based filter and common in Coffee circles to tweak incoming water TDS.

Water that is more pure also as a general rule will never grow algae or miscellaneous bugs like Legionella and others but neither does tap water when treated before it gets to most homes. Over time even demin or distilled water will grow bugs and algae as it gets to a more 'natural state' by re ionizing itself.

Both of those reasons above are the real reason for ultra clean water as chemically treating the Tube later is the only way to clean any deposits or gunk from the inside.

If you decide to keep and plumb in the R/O then fit one of these to a Human drinking spout which might seem dumb adding minerals back in but it tastes WAY better in Tea and Coffee and is far less likely to give gut troubles due to the pH. Something like this https://www.gpawholefoods.com.au/buy/remineralisation-cartridge-in-line/RO-IN-REMIN?gclid=Cj0KCQjw7pKFBhDUARIsAFUoMDasFuDUF1m7f9qXex-UDjdHK_YO5rSfLdTyeMMRwlPr5-pRuPM5NRsaApo1EALw_wcB

While that may be true for CO2 and semiconductor lasers, It is common practice for high power solid lasers e.g. Nd-Yag to have the whole cavity, including lamp connectons wet.
Typically the cooling system uses deionised water in a closed circuit with an ion exchange resin cartridge in circut to capture ions released from the laser components during operation. RO water is not the same and has higher conductivity (depends on feed water contaminants) then deionised.

[beanflying]

And where were we talking about non CO2 usage  Other than the grot/buildup factor the water doesn't matter at all for the stated purpose!

I did post some of this recently but one of my former Customers Eastman Kodak was dissolving the Copper out of Brass Impeller retaining nuts and they were crumbling on some of their R/O feed pumps with their water. In this case they were feeding heavily filtered Ion reduced water into their R/O plant and the resultant was measured in PPB not PPM post the tertiary treatment. The original so called consulting Engineers Fluor Daniel cocked up with the spec and only looked at the base construction material and not all of the bits.

The non Pumped R/O membranes are generally less of an issue as they tend to leave more Ions in the water. Be it R/O of most high grades, Demin or Distilled  the damage it can do can be terminal to what it touches including the Human Body.

[Robert763]

Well you didn't specify CO2 

[tggzzz]

Fleabay is really trying to be helpful - and failing dismally. Would I trust them to hide items they (randomly) guess won't interest me? Hell no! Not before they give me a clue as to why my car's details are relevant to a Tek TDR

[nfmax]

Perfectly logical - some of the larger Tek 'scopes won't fit in a small car

[beanflying]

Well you didn't specify CO2 

And again you choose pedantry as a 'reason' to argue a non point. Clearly the conversation was on CO2 cooling as it pertained to Brumbies new purchases both of a Laser and R/O water system.

If you choose not to follow the conversation and embark on some sort of point scoring for technical correctness sake because you looked it up on google then chances are you are in the wrong place.

[Brumby]

If anyone wants to continue discussion about subjects related to my laser machine, then please take them to a dedicated thread: The K40 laser cutter/engraver - My journey into the laser world..

There is more than enough of it on the TEA thread.

Thank you.

[Specmaster]

Back on topic, well sort of, this seller has some pretty high expectations https://www.ebay.co.uk/itm/393332165433? All the valves are missing, and I'd love to learn where he got that valuation from 

There is almost nothing on eBay lately that seems to me to be a reasonable bet, prices for none working gear is sky-high.

Edit: Just looked at the other photos, these have clearly been homemade and uses co-ax sockets for inputs 

Back in the day, the use of "Belling Lee" connectors for audio inputs was quite common, in both the UK & Oz.

Strange, I have never before encountered that, or maybe it was just on home brew gear. I've been working on and using audio gear and test gear since the early 60's and the only time I can remember seeing that before was on an early Advance RF signal generator as the output socket.

[Brumby]

Back on topic, well sort of, this seller has some pretty high expectations https://www.ebay.co.uk/itm/393332165433? All the valves are missing, and I'd love to learn where he got that valuation from 

There is almost nothing on eBay lately that seems to me to be a reasonable bet, prices for none working gear is sky-high.

Edit: Just looked at the other photos, these have clearly been homemade and uses co-ax sockets for inputs 

Back in the day, the use of "Belling Lee" connectors for audio inputs was quite common, in both the UK & Oz.

Strange, I have never before encountered that, or maybe it was just on home brew gear. I've been working on and using audio gear and test gear since the early 60's and the only time I can remember seeing that before was on an early Advance RF signal generator as the output socket.

I can honestly say I've never seen Belling Lee connectors used for audio.  RCA connectors were king here back "in the day" - which I consider to be the last four decades of last century ... as a minimum.  Belling Lee connectors came into their own for RF when TV antenna cable moved to coax.

[Brumby]

Desperate people might have tried using Belling Lee for an audio connection to an RCA socket as the outer shell could be made to fit - but the centre pin was too small for any sort of reliable connection.

[Neomys Sapiens]

The Height of Stupid with our system was some of the outs allowed. 'Coffee' is exempt as is 'Milk' as is 'Bread' and some other staples but put the Coffee and Milk together then it is taxable and a piece of buttered bread would be too. So if I sell Coffee Beans or Ground Coffee it is exempt but the packaging is not and if I make a coffee at a market then it is taxed even if it is only water added for a black coffee 

When VAT was introduced here in the 70s, it was 15% for luxury goods and 0% for other things. Not difficult for a blind man to spot the ambiguity.

As one example, some types of 1uF capacitor were 15% and others were 0%. The 15% ones were designed for use in a common luxury item: TVs.

The federal Sales Tax our GST was far more like that and was a complete pig breakfast with very bogus exemptions for some. Colour TV's and Cars from memory were 33% (of wholesale price) pre the $10% GST (on retail) is in theory an improvement but as an unpaid small Business tax collector it sucks four times a year. Generally any food items were exempt regardless too.

[beanflying]

Think less refined and far more messy

[mansaxel]

Todays barely TE related event is the discovery that the used expansion vessel I bought and fitted to the machine room cooling has a safety valve not set for 1,5 bar / 21 PSI but more like 0,22 bar. The bastard leaks. Broke it down to pieces, and have located a replacement valve and will have it shipped.

Now, on the fire and brimstone account, I've got a good reason to get my Army issue blowtorch up and running, since I'm going to solder a few of the pipe joints for the overflow connection from the safety valve.

Here's the original usage for the blowtorch, heating your truck / tank / offroad vehicle:

[mansaxel]

Back in the day, the use of "Belling Lee" connectors for audio inputs was quite common, in both the UK & Oz.

This is one of the days I'm happy we have had a significant influence from Germany. DIN connectors, while crappy, are ages better than Belling-Lee coax plugs, which are plain crap. Hell, they make the F connector look good.

Nowadays, I won't buy audio gear without XLR connectors and associated balanced interfacing.

[tonyalbus]

Organized the lab a bit... tetris time. also have a desklight under the desk ,  great for plugging replugging cables

I like the new position of the powersocket and my USB with powermeter also in the middle of the desk.. enough leg room left.
easy to connect all the little usb devices and see the consumpsion.

And my homebuild 19"still standing     (hope the floor will too)

[Specmaster]

Back in the day, the use of "Belling Lee" connectors for audio inputs was quite common, in both the UK & Oz.

This is one of the days I'm happy we have had a significant influence from Germany. DIN connectors, while crappy, are ages better than Belling-Lee coax plugs, which are plain crap. Hell, they make the F connector look good.

Nowadays, I won't buy audio gear without XLR connectors and associated balanced interfacing.

For home / domestic use, or indeed in most environments where the audio gear is going to be fixed, XLR connectors are a massive overkill, but for mobile use such as mobile DJ's, recording equipment that has to be moved a lot like outside broadcast units, film locations etc, I agree, XLR is essential because of its ruggedness.

[wkb]

Like one of my ham friends says when I build something "Wilko, it does not have to be MILspec..."

Me: "But does it hurt?"

[0culus]

Cubdriver (Pat)--if you're reading please check your discord PMs...I need to chat with you about something really cool! 

[Cerebus]

If you decide to keep and plumb in the R/O then fit one of these to a Human drinking spout which might seem dumb adding minerals back in but it tastes WAY better in Tea and Coffee and is far less likely to give gut troubles due to the pH. Something like this https://www.gpawholefoods.com.au/buy/remineralisation-cartridge-in-line/RO-IN-REMIN?gclid=Cj0KCQjw7pKFBhDUARIsAFUoMDasFuDUF1m7f9qXex-UDjdHK_YO5rSfLdTyeMMRwlPr5-pRuPM5NRsaApo1EALw_wcB

Oh please! One place I don't expect to find this kind of pseudo-scientific claptrap reiterated is by people on here. How is pure water at pH 7.0, compared to remineralised water at pH 7.4, is going to mess with the pH balance of the gut considering that the first place that water is going to visit is a stomach that has a pH of between 1.5 and 3.5 and that is in a body that has its own active feedback system for controlling the gut pH?

Bear in mind that pH is a log scale, so the pH difference between pure and remineralised water of 0.4 (10^0.4 = 2.5) is dwarfed by several orders of magnitude by the  pH difference between water and the stomach contents of pH 3.5 to 5.5 (10^3.5 ~ 3,200 to 10^5.5 ~ 320,000) . If drinking pure pH 7.0 water that is 0.4 pH different (2.5 times more acidic; or more accurately 2.5 times less basic) from 'normal' pH 7.4 remineralised water caused "gut problems due to pH" then the consumption of coffee (pH 5), orange juice (pH 3.3) Coca-Cola (pH 2.5, nearly 32000 times more acidic than pure water) would cause devastating symptoms. That guff about pure versus remineralised water causing gut troubles due to pH just does not make scientific sense.

The non Pumped R/O membranes are generally less of an issue as they tend to leave more Ions in the water. Be it R/O of most high grades, Demin or Distilled  the damage it can do can be terminal to what it touches including the Human Body.

Oh dear, it gets worse. Please cite, even a single, peer-reviewed scientific paper that demonstrates any of those forms of purified water being 'terminal' to a human body - I'll even permit a paper citing drowning as long as it attributes some of the harm to the purified nature of the water involved.

I don't really want to be so scathing, but it's difficult not to be when someone is holding out that water that is a tiny bit purer than we generally encounter is some kind of serious medical hazard, to the point of using the word 'terminal' associated with 'Human Body' to imply that pure water is a deadly poison. Common sense ought to tell you to be suspicious of such 'information'.

It just goes to show that scientists and engineers are not magically inoculated against believing or repeating old wive's tales, even through we like to think that our supposed rationality protects us from them. What hopefully sets us apart is how we respond once we start applying critical thinking to them.