Any Hams here?



Aw, C'mon Gunner! You 'passed' the test, right? You know what a Faraday cage is, right?
Put it all in a steel bucket with some grounding straps for the lid to bond to the body, and leave a little hole so you can see the lamp glow as you load into it!
Passed? Have they not included the basics, anymore? <G> Lloyd
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Traditionally it's a gallon paint can, with the RF connector in the center of the lid. The oil-filled Heathkit 'cantenna' was good for a kilowatt.
http://en.wikipedia.org/wiki/File:Cantenna.JPG
jsw
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Gunner wrote:


http://www.youtube.com/watch?v=Yx5F1jUFySM
Scale it up as needed.
--
Steve W.

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'course, with all those old gouging rods he has lying around unused, he could make a _real_ carbon-pile dummy load...
Lloyd
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On Thu, 21 Mar 2013 06:08:37 -0500, "Lloyd E. Sponenburgh"

I do have about 40 lbs of carbon gouging rods. Bit hard to solder them together though. Could make a couple plates with holes and set screws though...<G>
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wrote:

The old ARRL Handbooks had information on dummy loads. IIRC, they included instructions on making them.
Most public libraries have copies of old Handbooks. You'll find lots of useful things in those that's just skipped over today.
--
Ed Huntress
KC2NZT
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'bit useless, too. Think about it. IF not all, then most of the copper cladding would have to be removed...
Lloyd
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"Lloyd E. Sponenburgh" <lloydspinsidemindspring.com> wrote in message

That's an easy lathe job and you could pause to measure the increasing DC resistance. jsw
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Yeah, I didn't say it would be hard, just necessary. And soldering straps to the cladding would be easy, not "hard".
Mounting would have to be compliant, to accommodate expansion. I think clamping one end, and leaving the other end 'flying' would be best. Braid for connex.
Lloyd
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On Thu, 21 Mar 2013 09:22:23 -0500, "Lloyd E. Sponenburgh"

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Take a look at http://www.k4eaa.com/dummy.html
The Heathkit dummy load was good for a kilowatt for a limited time, but you probably do not need a dummy load for that much power.
You might be able to use one of your carbon gouging rods, but would need to take off the copper except at the ends and probably drill a hole thru the center to raise the resistance. That would also help with skin effect. Might be fun to try.
Dan
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are these carbon rods something that can be used to make a carbon arc lamp?
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Well, considering that their purpose in life is to make an... uh... Carbon Arc... Yeah, I'd guess you could.
I don't know what effect the cladding has, but it's easily removed.
(you got the voltage-actuated servos all built?) Lloyd
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On Mar 21, 1:54pm, "Lloyd E. Sponenburgh" <lloydspinsidemindspring.com> wrote: > Well, considering that their purpose in life is to make an... uh...

The cladding is copper. it burns off at the arc end and serves to reduce the resistance so the power is in the arc, not in conducting thru the rod.
Dan
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I'd try one in an etching tank. Dissolve the copper off.
Plate it onto something you want copper plated.
Martin
On 3/21/2013 4:54 PM, snipped-for-privacy@krl.org wrote:

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Then you have to quickly wash ALL the etchant out of the porous, absorbent carbon, especially that which is trapped under the end sleeves. jsw
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On Thu, 21 Mar 2013 17:18:08 +0000 (UTC), Cydrome Leader

I actually do have some of those unclad carbons too IRRC .
Want to make a lamp for the Blitz?
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I used to use a high power carbon pile in the labs.
Big and larger than 4 lunch boxes. The carbon is compressed or released to change the resistance.
I think 50 ohm would be a bit hard to come by. Ours was 1 ohm.
Martin
On 3/21/2013 5:24 PM, GunnerAsch wrote:

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I just measured a piece of carbon fiber insulation about .75" x 1.5" x 10" long at under 2 Ohms. jsw
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What is the wattage ? - sure I can buy drafting pencils from 6h to 6b. The B's are softer and more carbon and less clay. The clay and wax binds them together.
If one makes a pencil line of very soft pencil and makes it twice as long it would double the resistance. Make it twice as wide and it would half and so on.
The welding sticks (I have some Gunner sold/gave me.
As they heat, pencils will boil off the wax and become harder and fragile.
Martin
On 3/22/2013 6:41 AM, Jim Wilkins wrote:

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