Post Your Cool Pic Here! / General Chatting / Forums

Forums

4hv.org :: Forums :: General Chatting

« Previous topic | Next topic »

Post Your Cool Pic Here!

first previous 159 160 161 162 next last

Move Thread

LAN_403

Hon1nbo

Thu Apr 09 2009, 08:08PM

Registered Member #902 Joined: Sun Jul 15 2007, 08:17PM
Location: Pacific Northwest USA
Posts: 1042

here are some more pics of mine: a WWII Field Telephone set I picked up for $40 (Signal Corps Model EE-8-A), and some Raku Artwork (a guest artist at an arts festival crafted the ceramic, I glazed it)...

1239307714 902 FT6000 Raku Kiln Hot Pieces

1239307714 902 FT6000 Raku Kiln Pieces Cold

Mads Barnkob

Mon Apr 13 2009, 09:40AM

Registered Member #1403 Joined: Tue Mar 18 2008, 06:05PM
Location: Denmark, Odense C
Posts: 1968

On my easter vacation I spend alot of time on the Danish west coast that is basicly sandy and flat wet plains, a perfect breeding place for some of the animals we hardly ever see in we living in the the city :)

We ran upon 3-4 snakes, about 50cm+ and believed it to be a harmless grass snake, so I went as close as 20cm for some of the photoes, when we got home I looked it up and it turns out it was a Common european viper, the only poisonous snake living in the wild in Denmark :)

They have not yet nested this early, so they mostly ran off instead of attacking, atleast I got some good shots!

Proud Mary

Tue Apr 14 2009, 02:46AM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

I bought this splendid old 0-18.5 kV AC/DC electrostatic voltmeter on ebay for Â£10 (11 EUR / 98 NOK / US$15) and after a couple of hours work it is as good as new. The wooden case has come up wonderfully. I have tested it at three points along its scale, and it is as accurate as the eye can tell with an analogue meter.

Here it is, measuring the output of a 10kV NST:

1239676876 543 FT6000 Electrostatic Voltmeter A

Chris Cristini

Wed Apr 15 2009, 01:10AM

Registered Member #1749 Joined: Fri Oct 10 2008, 02:04AM
Location: Claremont New Hampshire
Posts: 497

A lot of power sitting in one spot.

And here is somthing I am proud of.

Proud Mary

Wed Apr 15 2009, 01:53AM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

MadsKaizer wrote ...

we got home I looked it up and it turns out it was a Common european viper, the only poisonous snake living in the wild in Denmark :

A splendid picture of a viper (also more commonly called "an adder" in England, but both are correct)

Like Danmark, it is the only poisonous snake we have in Britain, and though people are frightened of them, there is only one definite recorded death by adder bite in Britain since 1900.

A few years ago, one sunny day, I went ashore on an island in the Hebrides off the west coast of Scotland - an island uninhabited since the 1930s - and have never seen so many adders in all my life! With no humans to bother them, and few predators, I saw perhaps six or seven drowsy snakes sunbathing on sandy spots amongst the heather in my first hour or two ashore.

The snakes were untroubled by my appearance, and I just walked quietly by at a good distance, without the reptiles stirring from their sunbathing, but I wish I had been able to take pictures of them as you have.

Last summer I visited Pevensey Castle, a Roman fort about 50km from where I live - and was lucky anough the see a grass snake swimming in the moat, moving along the edges among the reeds, perhaps looking for young frogs. I was standing on the drawbridge that leads into the castle gate, and so was able to look straight down on the grass snake hunting in the green water, where I also noticed some tench.

Grass snakes have a very visible white ring behind the head, whilst the adder, as you know, has its splendid zig-zag pattern.

Wonderful stuff. Thank you for sharing this fine picture with us.

Cesiumsponge

Wed Apr 15 2009, 04:08AM

Registered Member #397 Joined: Wed Apr 19 2006, 12:56AM
Location: Western Washington
Posts: 125

A couple more random abstracts as I progress on my mystery project.

1239768424 397 FT6000 3414002104 B953abcefc B

1239768424 397 FT6000 3414003082 Bbe80432a0 B

Proud Mary

Wed Apr 15 2009, 08:33AM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

Mercury-Argon Thyratrons Type 393A

I bought these two beauties, new and boxed, to drive the Rayleigh pulse forming networks with which I'm amusing myself at the moment.

Specs are:

1250V forward and reverse
6A peak
55A surge
120A 100ms (max recoverable fault)
g1 -500V
Ti 10us @ -500V g1
voltage drop 10V
PRF max 420 Hz.

filament 2.5V/7A

You can see condensed mercury on the inside of the glass of the valve with its back facing upwards.

They are a bit sluggish as thyratrons go - best ionization time is 10us with -500VDC on the grid - but in single shot firing no harm will come to them switching 30A, which is a good old wallop at 1250V .