John Curl's Blowtorch preamplifier part II

[myhrrhleine]

T
Wire, connectors, and case have been covered...

um, a question.
does trace weight matter?
if so, what is your preference?

 

[john curl]

I don't know, I leave it to my associate Carl Thompson, but I am pretty sure we use wide and thick traces.

 

[scott wurcer]

As far as I'm aware, you don't get a diode if you go from copper, to copper oxide, to copper. You have to go copper, to copper oxide, to something other than copper. I believe lead was commonly used for that in copper oxide rectifiers.

se

Could be I don't know, but the guy with the copper photocells was using oxidized pc board and a copper wire to get some photovoltaic action (could have been the salt water drop contact).

 

[Steve Eddy]

Could be I don't know, but the guy with the copper photocells was using oxidized pc board and a copper wire to get some photovoltaic action (could have been the salt water drop contact).

Yeah, perhaps the saltwater was working as an electrolyte.

se

 

[simon7000]

Could be I don't know, but the guy with the copper photocells was using oxidized pc board and a copper wire to get some photovoltaic action (could have been the salt water drop contact).

Copper as I recall from the Morgan's Boys Book of Electricity series has two oxides, cuprous and cupric. An electrolyte between these two coatings will when illuminated produce a voltage.

Does this mean we now have to paint our audio cables black?

 

[scott wurcer]

Copper as I recall from the Morgan's Boys Book of Electricity

I have a boy's (and girl's) hobby book from the 30's. It's amazing how sophisticated and dangerous some of this stuff was. No video games.

 

[john curl]

Well, apparently they did know about differences in materials in Boy's books in the 1930's. Scott is right, as I have a high school chemistry book from 1938. They basically give you the formulas to make explosives. They would not do that today, but then, maybe, they thought that people who got interested in such things would go on to make better explosives when they grew up. ;-)

 

[Joachim Gerhard]

when i was 14 i got a recipy for black pouder. my friend and i saved money for 3 month and fired up around 1kgr at new years in a metal can. the flame was at least 3m high and my mother got scared. it´s a miracle that i surviwed my youth.

 

[john curl]

Me too, I accidently lit fire to the gunpowder I was making on my desk in my bedroom. Jack Bybee burned down his garage, the same way.

 

[Joachim Gerhard]

i remember the recipy. 30% sulfur, 30% salpeter and carcoal powder. we got the ingredience in the lokal pharmacy. sulfur was for scaring animals from eating plants etc.we told the pharmacist. the problem was to get really well grinded carcoal so we did not get exposions but quite violent fire. we where totally ocupied with this job. our other ocupation was light so we connected the transformers of our play trains with car lamps we saved from the lokal car junkjard. where are this junkjards today ? they have miracolously disapeared in germany.

 

[Joshua_G]

Junkyards seem to have disappeared everywhere.

 

[scott wurcer]

i remember the recipy. 30% sulfur, 30% salpeter and carcoal powder. we got the ingredience in the lokal pharmacy. sulfur was for scaring animals from eating plants etc.we told the pharmacist. the problem was to get really well grinded carcoal so we did not get exposions but quite violent fire. we where totally ocupied with this job. our other ocupation was light so we connected the transformers of our play trains with car lamps we saved from the lokal car junkjard. where are this junkjards today ? they have miracolously disapeared in germany.

I just emptied the contents of my grandfathers shotgun shells.

 

[Joshua_G]

I just emptied the contents of my grandfathers shotgun shells.

Well, you are taking short cuts …

 

[Joachim Gerhard]

Aha, you can the be a child again.

 

[brianco]

If you take a largish bore bullet (I tried with an old 9.5mm Mannlicher) and drill out the nose dum-dum style but quite deep and then part fill the cavity with a little glycerine, you can take out a small tree very effectively! Mind you I was a mid 20s child in those days!

 

[syn08]

I just emptied the contents of my grandfathers shotgun shells.

So did I. And mixed the gun powder with some manganese dioxide from old Leclanche cells to slow down the burn a bit.

Carefully balanced rockets were sometimes flying high, some times not so much. Then I learned about the pendulum fallacy.

 

[Joachim Gerhard]

what about filling empty eggs with fuel and building little water rockets

 

[john curl]

We had trouble with the pharmacy getting Saltpeter. They knew we were up to something.

 

[syn08]

If you take a largish bore bullet (I tried with an old 9.5mm Mannlicher) and drill out the nose dum-dum style but quite deep and then part fill the cavity with a little glycerine, you can take out a small tree very effectively! Mind you I was a mid 20s child in those days!

To complicated. Some cotton balls and a dip into nitric and sulphuric acid fumans was good enough.

Or iodine crystals and some ammonia to get those light violet perls.

 

[Steve Eddy]

I just emptied the contents of my grandfathers shotgun shells.

Same here.

What we'd also do is remove the shot, tape marbles to the primers, and toss 'em out in the street.

se