Test Equipment Anonymous (TEA) : Discussion and Group Therapy Thread

[mnementh]

Yes it is the diesel that worries me. I don't think anyone understands exactly how much diesel an average datacentre can guzzle. The batteries last a few minutes. The tanks last a few hours if you are lucky. But the batteries take hours to charge. The diesel supply is already constrained.

The whole thing is built around a single outage rather than persistent energy shortages.

Yeah, as I suggested... "more like zombie-apocalypse grade and duration downtime, at least to those in critical IS roles."

mnem
*toddles off to watch as Amazon buys whole fleets of oil tankers*

[mansaxel]

Yes it is the diesel that worries me. I don't think anyone understands exactly how much diesel an average datacentre can guzzle. The batteries last a few minutes. The tanks last a few hours if you are lucky. But the batteries take hours to charge. The diesel supply is already constrained.

Around here, the norm seems to be about 48h supply on premises. The main reason for comms outages in 9/11 (apart from what was knocked out by being in the towers) came a couple days after; when Manhattan was blocked to all traffic, including diesel trucks. One after another the telecoms sites shut down, most for lack of refuelling, but some also to overheating since their chillers were blocked with paper from the towers.

The whole thing is built around a single outage rather than persistent energy shortages.

That much is true. Statistically, it makes sense. The further out on a branch you are, the smaller and more likely is a disturbance that will affect you. Therefore, the outage you must plan for (because it will happen, often compared to others) is that one site loses power. The total grid failure scenario is something only military comms can survive, and that mainly because they've got large diesel tanks.

[Zenith]

I can't say The Guardian is one of my regular reads, but I'm pleased they are slowly catching up.

The Grauniad will (like Private Eye) print things that other media is to scared to print.

Private Eye is Private Eye and a shadow of its former self.

The Guardian I've always seen, (since around 1970) as a tat rag aimed at the bien pensant.

Apart from that, the PPAuctions stuff is half up on its site, and there's a Ramco next week.

The problem with PPAuctions is the goods are in Lincolnshire and it's a total 7 hour drive to collect them. They don't appear to have a dispatching service. They have a number of interesting items, but I'd have to succeed in a few at knock down prices to make it worth while. 15% buyer's premium + VAT. The £100 successful bid becomes the £138 bill with some messing about and a long and expensive trip (£50 for diesel) to collect it. Perhaps I've missed something here. If it was 50 miles away I'd give it a go. There are some items in Bicester, but nothing I want.

Ramco looks better, but they are not offering anything I'm gagging for.

The stuff in Bicester is hunt4auctions, presumably stuff that hasn't sold quickly enough previously. hunt4auctions on bidspotter/ibidder has the irritating habit of setting a low starting price that is below the minimum price they will accept. Timewasting.

PPAuctions is OK-ish provided you can get multiple things cheaper than at Ramco. Ramco have stopped sending overseas, presunabky because of the new Brexit red-tape. Might mean there are fewer bidders, but I wouldn't bet on it.

The trip to PPAuctions in Aunby/Stamford is indeed a pain, but one that I've tolerated in the past. I've had some nice stuff from them as well as some that was binned after stripping out any bits worth keeping. A significant issue is that they keep stuff in a farm outbuilding, under hessian to reduce condensation! This auction stuff will only have suffered that for a couple of weeks, whereas the spring auction stuff has overwintered like that.

In the past I've just ignored the petrol costs, but that has to be questioned now. But that's coming from someone that went the same distance to Hackgreen

Hack Green was different in that it was unknown and there was the secret nuclear bunker to visit. I gather that having done it once you won't do it again. Driving up to pick an item of TE you paid £150 for all considered, plus £50 in juice, (and the boring drive to pick it up and drive straight back), is a different proposition. To make it worthwhile, you'd expect to be able to flip it for 5 ton at least. Now you could pick up several items at reasonable (low) prices, and that would be different, but you might only succeed in one, and that fairly cheap. I've no idea what these items fetch eventually.

If someone asked you to drive up to Stamford and back as part of a sociological experiment to do with the psychology of transport, and they'd pay the fuel bill - they watch you fill your tank before you go, and when you return they fill it up again - what would it cost to induce you to do it?

[bitseeker]

Robert, what do you like most and least about the HP 3325A? I often see them for sale.

[mansaxel]

Robert, what do you like most and least about the HP 3325A? I often see them for sale.

I don't have one, but I want one! The CuriousMarc series on function generators did not help.. Might be so that I want the B model a bit more. Of course they're rare and expensive in Europe.

[Cubdriver]

I did pick up the Myford ML 7 lathe and have that in the garage on it's stand. Not fitted the motor unit yet though as I'm putting s new 3 phase motor and Variable Frequency Drive on it. The old(er) ML2 is in the overflow garage and will be on ebay shortly.

Robert.

Robert -

We need pictures of the lathe!

-Pat

[Robert]

Robert, what do you like most and least about the HP 3325A? I often see them for sale.

They were a bit of a standard. Apart from the size there is nothing not to like for what it is. Still hard to beat for very low frequencies and few of the modern small units can match the 11 digit frequency and 0.01dB (4 digit) amplitude resolution. The aux output goes to 61MHz so total range is 1uHz to 60MHz

[Robert]

I did pick up the Myford ML 7 lathe and have that in the garage on it's stand. Not fitted the motor unit yet though as I'm putting s new 3 phase motor and Variable Frequency Drive on it. The old(er) ML2 is in the overflow garage and will be on ebay shortly.

Robert.

Robert -

We need pictures of the lathe!

-Pat

Not in place yet and moorising unit not fitted. The shelf behind has to go...
EDIT would not take a 245kB image, said it was over the 256kB limit

[Robert]

Image @<100kB

[mnementh]

(SNIP for brevity's sake)
...EDIT would not take a 245kB image, said it was over the 256kB limit

Yup. I have no idea what the actual fuck is with phucked-upBB on that issue; I've had it do the same on a 145KB file. So far, I don't see any rhyme or reason as to which file it will have a shit-fit over either.

mnem
*toddles off to buy a rake*

[Cerebus]

Yes it is the diesel that worries me. I don't think anyone understands exactly how much diesel an average datacentre can guzzle. The batteries last a few minutes. The tanks last a few hours if you are lucky. But the batteries take hours to charge. The diesel supply is already constrained.

If I have the arithmetic right, then 1l of petrol has about 30MJ of energy. Hence 100l of diesel will have - roughly - 1MWh of energy.

Now, what's the power consumption of a datacentre? Assume a 25% efficiency, and that will indicate how much diesel is going to be guzzled.

You're not far off, UK official statistics based on actual diesel imported/sold in the UK: 43 gigajoules/tonne with a density of 1200 litres/tonne. That gives 35.8 MJ(t)/litre.

The standard rules of thumb are 0.4L of diesel will generate 1 kWh of electricity (or 1L diesel => 2.5kWh) and diesel generators are indeed about 25% efficient when run at a well designed load point (i.e. 1 MJ(t) => 0.25MJ(e) => 69.4 Wh so 2486 Wh/L for 35.8 GJ/L diesel).

Factor in that typical datacentre power availability figures are 1 - 3kW per rack, that each of the datacentres in London docklands (I can count 10 buildings without without bothering to enumerate the smaller ones) houses over 1000 racks a piece and, at an absolute minimum you're looking at 10,000 racks * 2kW each, for an instantaneous demand of 20 MW just on the Isle of dogs which leaves you looking at 8,000 litres per hour (6.7 tonnes per hour) of diesel fuel just for the Isle of Dogs at an absolute minimum. That's 192,000 L/day, or 5.3 full size 36,000L tanker loads. The real figure is probably considerably higher.

[bd139]

That's close to the figures our risk analysts got before immediately going outside to smoke and cry.

I have a feeling that there is an opportunity to make some money of this existential risk. Of course that's what I'm lining up for...

[Cerebus]

I have a feeling that there is an opportunity to make some money of this existential risk. Of course that's what I'm lining up for...

I bet there's people at the various colo companies buying diesel futures like they're going out of fashion. In turn, those futures are going to cause some of the people selling them some real, unexpected, headaches: "What you mean 'The delivery address is Coriander Avenue, Dockands.' ?!?"

For the uninitiated although futures purchases are theoretically buying the right to buy, at a certain price, a certain quantity of a certain commodity at a certain time in the future the "futures market" has long been divorced from the reality of the underlying physical commodity and most futures options contracts change hands with no expectation of physical goods changing hands. Sometimes the financiers get confused between an options contract and an actual futures contract. This has occasionally led to hilarity when vast quantities of physical goods (e.g. 20 barges of coal) have turned up at financiers offices, and situations where financiers suddenly had to try and find real physical goods to fulfil a futures order that they were left at the sticky end of.

[mnementh]

That does sound vaguely familiar...

mnem

[bd139]

Ah yes the miracle of knowing what you are doing at the start of the problem but realising you were wrong at the end, a common human mistake. Good to learn those from other people's mistakes.

[Zenith]

The six stages of a big project.

1. Unbounded enthusiasm,
2. Total disillusionment,
3. Panic, hysteria and overtime,
4. Frantic search for the guilty,
5. Punishment of the innocent, and
6. Reward for the uninvolved.

With UK government IT projects it seems that the guilty are well rewarded and go on to higher things.

[vk6zgo]

The six stages of a big project.

1. Unbounded enthusiasm,
2. Total disillusionment,
3. Panic, hysteria and overtime,
4. Frantic search for the guilty,
5. Punishment of the innocent, and
6. Reward for the uninvolved.

With UK government IT projects it seems that the guilty are well rewarded and go on to higher things.

In my experience, both the innocent & the initially uninvolved are stuck in perpetuity with trying to make the bloody crap thing work, whilst the original perpetrators are feted for their "visionary approach to things"!

[bitseeker]

(SNIP for brevity's sake)
...EDIT would not take a 245kB image, said it was over the 256kB limit

...I've had it do the same on a 145KB file. So far, I don't see any rhyme or reason as to which file it will have a shit-fit over either.

I don't recall a byte limit, but the dimension limit is currently 2000 x 2000 pixels. I'll dig around to see what I can see.

[bitseeker]

Robert, what do you like most and least about the HP 3325A? I often see them for sale.

...Apart from the size there is nothing not to like for what it is...

Yes, size is a limiting factor. When I started TEA, I was going to stick with only half rack width equipment, but that only lasted a few years. So space is a problem

[Zenith]

Even if you have the room and shelving, some things such as huge old Marconi Signal generators, are too bulky and heavy for serious consideration. Their size and weight also makes them harder to get rid of, with shipping charges and the fact they are basically less desirable.

OTOH, some things, such as those little generic RF and AF signal generators, rebadged as Tenma and dozens of others, seem to fetch a surprising price on ebay, despite not being very good performers. I'm sure it's because they are small and light.

[Zenith]

(SNIP for brevity's sake)
...EDIT would not take a 245kB image, said it was over the 256kB limit

...I've had it do the same on a 145KB file. So far, I don't see any rhyme or reason as to which file it will have a shit-fit over either.

I don't recall a byte limit, but the dimension limit is currently 2000 x 2000 pixels. I'll dig around to see what I can see.

I'm sure when I added photos to a post a few days back, the limit was 256kB. It's now 10Mb. You may have increased it.

Is there any good reason why we should keep images no bigger than they need be, such as cost, or running out of space?

[Specmaster]

BD, did you find anything of interest in that PP auction catalogue? When I looked at the items on their website, the only thing that caught my eye was a TTi 1906 bench meter which has plenty of functions, otherwise it was nearly all dedicated stuff for special applications.

[Zenith]

There's quite a lot of general purpose TE in that catalogue, including bench DMMs. Use the search function for "Tektronix", "HP", "meter", "spectrum" etc, to cut down the amount you have to wade through to see what you are interested in, and avoid digital frame store synchroniser timebase correctors etc.

What I find off putting is that you have to collect the items and it's a long drive up to Lincolnshire. To make it worthwhile I'd have to bid successfully for a couple of items and they'd need to be fairly pricey things I got at lowish prices. Note the buyer's premium and VAT. If it was in Swindon, lets say, it would be much more interesting.

[Specmaster]

Agreed, it is 200 mile round trip for me, about 4 to 5 hours driving and around £38 in fuel, so It's not really viable for me either, although I have done it once, 3 and a half years ago actually, when the fuel would have around £20 so with 2 x Solartron 7050 plus bench DMM's I was collecting and the subsequent flipping of them after some repair work was done to them, I probably came out on the right side of the equation in the end. But without a delivery option I would not want to repeat it today.

[bd139]

BD, did you find anything of interest in that PP auction catalogue? When I looked at the items on their website, the only thing that caught my eye was a TTi 1906 bench meter which has plenty of functions, otherwise it was nearly all dedicated stuff for special applications.

Nothing major actually. Was a little disappointed.

TBF I'm not really in the market for any more stuff at the moment. Time and attention aren't available due to work and family commitments. Also I need to clean out some of the garbage so am selling the crap I am not going to bother repairing and some things which are a liability and the stuff I bought to flip anyway or nick parts out of to make other stuff good.