Hello Jan,

JP> Yes, I remember a German university maybe 10 years or so ago modulating
JP> the office lights to make a LAN.

JP> Much longer ago I started playing with IR diodes and lasers, at that
JP> time helium neon lasers.

I have a hearing aid for tv listening that also works with IR.
The first version was in mono and is much affected negative by the new low
energy saving lightbulbs ;-(
I had to place an emty toilet rol at the receiving ir led to catch the
transmitted signal from the unit near by the tv set.
You know this Sennheiser HD407S ?
The later Ri810S sereo IR set did not have that problem.
I also have FM version RR820S for the hard of hearing.

JP> Here a warning is in place, apart from Schiphol airport alert that some
JP> alien spacecraft was detected the same day I tried the HeNe thing,
JP> I also got hit in the eye by a simple reflection from a thee spoon in
JP> the room, no harm done, but it did hurt, so beware.

I know, so never look into IR ligths. I now have a Bosch distance meter wit IR,
and since last year a Fluke 62 Max IR thermometer also with Led,
but you can switch that red signal light off, if you want to.
It works great up to 500 oC. I use it to signal the temp of very many things,
but especially the diesel engines of my brothers inland ship, i.e cooling
water, and exhaust temps.

JP> This because I see they want to go and use laser pointers.
JP> Also the pointing with lasers is very critical.

Yes.
May be later on we get IR protected glasses to wear?

JP> This is one of my arguments against those scanning lasers for
JP> selfdriving cars, with millions (several per car) scanning lasers
JP> around I do not want to be on - or near the road.

Yes, and for childern it is even more dangerous.
But I think it is the same laser as used in supermarkets for scanning
the goods you want to buy?

JP> BTW did you receive my email about that large file

Yes I did, but I was so busy after two weeks sailing in the second half of
March, that I still did not have the time to answer your mail, sorry.

JP> and did you get it?

No, but I still would like to get it.

JP> because I removed it again after a while.

That is a pity.
Can we arrange another try?

JP> I think, personally, digitenne is dead.

For the type 1 system you are right,
but the new Type 2 has much more quality like HD tv

Henri.

---