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Re: Dayton ham and cheese fest (fwd)





---------- Forwarded message ----------
Date: Mon, 18 May 1998 14:33:37 PDT
From: Bill the arcstarter <arcstarter-at-hotmail-dot-com>
To: kevin+-at-cs.cmu.edu, tesla-at-pupman-dot-com
Subject: Re: Dayton ham and cheese fest

Coilers,
 I wrote:
> Jeff Harvey (of tesla-2) and I survived day 1 of the Dayton Hamfest. 

Then Kevin wrote:
>Whew!  So, how is *your* sunburn?  I got fried!  :-)

I was prepared for the sun on friday - hat, sunglasses, and suntan 
lotion.  However, when I left the house on saturday the weather was 
overcast and rain was predicted.  By the time I arrived - not a cloud in 
the sky.  To make a long story short - I've been basically incinerated 
and could barely walk on sunday due to the backs of my legs being 
burnt...  But it was worth it!

By far - my best "find" was a 70's vintage Monsanto model 111 1 to 512 
MHz digital freq counter for $10!  The seller said one of the Nixie 
tubes had both the '4' and '5' digit illuminated.  I looked through the 
side and saw a bunch of 74xx socketed dips - so I decided to risk it!

Turns out that one 7441 BCD to 1 of 10 driver chip later - all was well!  
It needed a bit of pencil eraser work on some PCB edge connectors too. A 
working seven digit resolution 1 Hz to 512 MHz counter for $10.  I'm a 
happy guy.  One input runs from 0-10 MHz - the other from 5MHz to 512 
MHz.  Inside is a downconvertor board which (apparently) maps the 5-512 
MHz input down to something a bit more countable by the digital counting 
section...  Five ranges from Hz to KHz to MHz.  It also has a pulse 
counter function which I haven't fooled with yet.

>I saw one gargantuine ignitron.  It was laying on the ground next to 
>a great big capacitor (I think the same cap you mention in the next 
>paragraph).  I didn't recognise it as an ignitron first, due to its 
>enormous size.  It is a stainless steel cylindar 6-8 inches in diameter 
>and about 2.5 feet long.  I picked it up to feel the Hg sloshing 
>around in there - It weighs 20 - 30 pounds!  It makes the 7171 
>ignitrons that I have seem like toys.  :-)

Yep - I saw it.  It had a "B" written on the side - perhaps for Bad?? I 
wonder if the mercury itself would have resale value??  I put it back in 
the box...

Does "sloshing" an ignitron ruin it, or would it be OK if you left it 
upright for awhile??  How can these things fail?  They will tolerate 
some truly massive current surges w/o dying.

>sparker used for testing neon tubes for leaks ($3 - the guy thought it 
>was a high voltage probe), a cute little sun-tanning device, 
>consisting of a bare, unshielded Hg vapor quartz arc lamp to 
>produce the UV necessary to give you a tan (Mercy!  Imagine the 
>law suits if they sold something like that these days!  The directions 
>that came with it said to avoid looking at the Hg lamp when it's on.  
>Hee hee hee hee...), aaaand a

You could use that UV tube to erase EEPROMs and things like that. (I 
know I would)  Did you see the guy selling the ancient diathermy and 
"Violet Ray" equipment??

But the best part was that about 7-8 coilers showed up at the appointed 
time on saturday.  Bert Hickman and I swapped "shrunken quarter" 
stories. Tristian Stewart, R. W. Stevens, and a few other fellows (their 
names elude me) were there as well.  I had fun showing my pictures and 
viewing the even more incredible pics these other guys had!  Kind of 
like a mini-teslathon!

Thanks, everyone, for showing up!  See you next year!

-Bill


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