Brian

Interesting views from the experts now about how reliable temperature checks are as a way of detecting someone's health. Especially as it now looks like you are most infectious in the day or so before you notice any symptoms.

Thanks for the interesting post; it's always nice to get the view from on the ground. As it happens, last night I was catching up on some back issues of New Scientist and read an interesting article about Michael Baker who devised NZ's coronavirus strategy and the lockdown hard and lockdown fast approach.

And it gets worse...

Ditto. It should have no connection to Earth so I'd start by looking elsewhere, specifically the mains input filter block. I can't remember if the output from the filter is on push-on spade terminals or is soldered. Try removing the output from the filter to the rest of the unit. So all you have in circuit is the input socket, the switch and the filter block.

But the caretaker is a trained electrician so may be willing to undertake this.

The dimmer has in-built test facilities. See this... contractor-24-dd06.pdf

High but not unreasonable. The chances of finding any schematics for these are quite small; they certainly pre-date the 'net. But all is not lost. Could you take some photos of the inside of the desk and its circuit board and post a link to them? You can't directly upload photos here so you'll need one of the many free photo hosting sites and them a link in a post here.

When you fit a new fuse disconnect the speaker BEFORE you turn the amplifier back on. Turn it on and see what happens. If the fuse stays OK then I'd be inclined to put a multimeter, set to DC volts, across where the speaker would be connected. You should only see a very small DC voltage if anything. Anything over 0.5V would indicate a knackered amplifier.

Before you spend that sort of money you really need to check the drivers out. Do you have a multimeter? If not, go and buy one.

I wouldn't go that far. Having spent the last 15 years making lots of smoke in lots of professional venues I'd reckon that fewer than 10% have, what I would call, a good air-handling system. I think the best I came across had the air inlets actually set into the floor, by way of grilles, with extract sited in the ceiling above. That's lots of inlet points and lots of extract points. But as Jon says, this really is a job for the professionals. Trying to work out a DIY system will mean spending money on a system which won't work.

Pins 2&3 swapped?

I have just hidden lots of off-topic posts. Whilst the current situation is indeed worrying on many levels, this topic is about cleaning microphones so let's keep it that way.

One assumes (dangerous I know) that the theatre they ran on the Uni campus is actually owned by the Uni? And the one in the city centre is probably owned by the developer of that part of town?

How much is a new dimmer? Seems daft spending more than the cost of a new one on protection. Or buy yourself an SMT workstation and learn to replace them; it's not difficult. In fact, you *might* be able to do it with a normal iron and a few tricks.

I don't know about other smaller regional theatres but my local one gets something like 70% of its annual income from Panto season. If solutions aren't found by the autumn I can see a lot of venues going to the wall at the end of this year.

It's interesting, and maybe an indication of how venues ought to be thinking, that HSE are very active on the subject of ventilation and air conditioning at the moment. One only has to look at the outbreaks in meat processing plants to see the importance.

I've got a couple of Milford Instruments 8-way relay boards listed on eBay if anyone is interested. The first one is here; the other can be seen by clicking on my other items.

Unless I'm much mistaken, germicidal lamps are normally used at relatively close distances. With them mounted on the ceiling of the auditorium they going going to need to be the mother of all lamps to get sufficient UVC down where it's needed. And how many auditoriums have sufficient mounting points to overcome any shadowing?

The coverage is just down to choosing the right lens. As for IR, I'm sure the JVC units I have can be switched into non-IR mode. I'll try to remember the model number when I'm at the store in the morning. I have a pile of them bought S/H on eBay.

HSE have just published some guidance. I wasn't thinking about show relay - that can be any old mic stuck anywhere. I was thinking about people doing isolated mixes. Isn't that what happens anyway when you mix from the auditorium? The demos I've heard of dummy head techniques are amazingly 'real'. And is complete isolation such a problem? After all, every OB mix is done in isolation. If you trust your monitoring, and have it set to fairly represent what comes out of the PA, then surely it should sound the same.

Has anyone ever tried a dummy head mic arrangement fed into cans for remote audio monitoring

So is the idea that people walk through some sort of tunnel which is filled with this anti-viral fog?

As I regularly go to the theatre as a punter I was invited to take part in the Indigo survey. I found the questions they asked very thought provoking. If you haven't seen it, the results are here, it's well worth everyone having a read... After-The-Interval-Wave-1-Report.pdf ...have a careful look at the questions asked before you study the results.

The insert points are early on in the path from the mix busses to the finals group and main outputs. The circuitry between the busses and the insert jacks is identical for both group and main so the noise should be the same here. If it is then the noise is coming in later on, if they are different then we need to look elsewhere.

Running the width of the desk are 4 Mute busses controlled by the mute group buttons on the aux master module. 0V means un-muted, -17V means muted. The can be found on CN2 pins 3-6. If you put a meter on these they should switch between 0V and -17V as you press the mute buss masters. Compare the level of hiss at the insert points for the groups and mains. They should be the same there as along as you have the same number of input channels routed to both groups and mains.