
The Museum of RetroTechnology - tomatotomato37
http://www.douglas-self.com/MUSEUM/museum.htm
======
tlb
I remember when microphones were physically dangerous. It mentions carbon
microphones with the main supply voltage going through them:
[http://www.douglas-
self.com/MUSEUM/COMMS/mechamp/mechamp.htm...](http://www.douglas-
self.com/MUSEUM/COMMS/mechamp/mechamp.htm#tann). But even into the 80s,
microphones plugged into portable vacuum tube amps sometimes ended up with the
plate voltage (200+ volts) on them and shocked people when they touched them.
Stage performers usually brushed a mic quickly with a finger before putting
their lips close to it, to make sure it wasn't electrically hot.

I wonder if it resulted in people being more careful what they said near a
microphone too.

~~~
scarecrowbob
Oh, mics are still dangerous. I play a lot of restaurants where you get odd
hums... one way to "deal" with that is to remove the safety ground on your
guitar amp.. of course, there is then a possibility that there is a difference
in potential between yourself as grounded through the amp and yourself as
grounded through a microphone... you don't need a carbon element or a tube amp
to get badly shocked that way. I and a lot of my dirtbag musician friends
still will touch a mic before using it.

~~~
hal9_0e3
Have you tried using an isolation transformer?

[http://www.shure.com/americas/support/find-an-
answer/transfo...](http://www.shure.com/americas/support/find-an-
answer/transformers-when-to-use-and-how-does-it-work)

------
crispyambulance
Douglas Self is the author of some really excellent books on audio
electronics. Especially "Small Signal Audio Design"
([https://www.amazon.com/Small-Signal-Audio-Design-
Douglas/dp/...](https://www.amazon.com/Small-Signal-Audio-Design-
Douglas/dp/0415709733/)).

------
sandworm101
I remember pneumatic tubes. Only a few years ago, Costco was still using them
to deliver checks/cash to their tills. I cannot say exactly when, but well
into the 2000s.

~~~
ansible
I was amazed / impressed to read that some of the pneumatic tube systems in
cities were operating for over 100 years. That's a long time for any given
technology.

------
ghostbrainalpha
The "Combat Cutlery" was absolutely worth the click.

From now on I will be a little disappointed with every spoon I use, that is
not also a firearm.

~~~
reaperducer
Visit the Prison Museum in Huntsville, Texas.

You'll be amazed by the deadly and complicated things that can be built with
little material but a lot of time.

------
andbberger
I appreciated the bit about pneumatic tubes. For whatever reason, I have been
itching lately to find technical details on modern packet-switched pneumatic
tube networks [1]. They're still used in hospitals apparently.

[1] [https://youtu.be/W39qQE5jqWk?t=55s](https://youtu.be/W39qQE5jqWk?t=55s)

------
agumonkey
thanks for this, I learned something I never heard of before: compressed air
power grid [http://www.douglas-
self.com/MUSEUM/POWER/airnetwork/airnetwo...](http://www.douglas-
self.com/MUSEUM/POWER/airnetwork/airnetwork.htm)

old times weren't so low-tech, this feels like steampunk^2

------
Apocryphon
I'm really digging how the top entry is the Shakespeare Mangle, a cipher
machine for conspiracy theory gibberish.

