| Re: Top Plates [message #30607 is a reply to message #30591] |
Sat, 19 February 2005 14:21   |
Skip Pack
Messages: 51
Registered: May 2009
Location: Hollister, California
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Baron |
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As a non_participant, but interested obseerver, I wanted to float
an idea here on top plates. When I built my Foreplay a couple of
years ago, I wasn't totally comfortable with the thin top plate
though it doesn't seem to have caused anyone any difficulties
(the new Bottlehead kits are coming with thicker plates). I
for reasons that changed, got two Foreplay kits, so I built the
one preamp using two plates with a layer of soft, thin
packing foam in between. There are enough through mounting screws
to hold it tight, and it is very stiff, and very dead. My only
reservation was problems with heat and flammibility. The Foreplay
has always run cool, and there have been no problems. I'd think this would work with any metal. You would need to
make sure you had a good connection between plates to avoid
making a funky capacitor, and grounding the plate(s) to anything
other than power ground would probably be bad. Skip
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| I like it [message #30640 is a reply to message #30607] |
Mon, 21 February 2005 20:46 |
colinhester
Messages: 1349
Registered: May 2009
Location: NE Arkansas
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Illuminati (3rd Degree) |
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Pretty good idea. It might be worth it asking Doc to make a one-of-a-kind plate. It would be just a call to his CNC shop. The setup is already done and the cost difference should be just the materials. I've got to do something about the buzzing in my FP. I bought the kit in '98, just as something to do. Little did I realize this kit would be a giant killer. I need to go back and do a nicer job on it. I also bought Doc's original PARASex amps, which I still use everyday. I got one of the last ones he sold and was upgraded to the 8.1 iron. As far as Guinevere is concerned, I'm using 20 ga copper sheeting which is way too thin. I'm having to do some supports under the hood just to keep the top for sagging. The Heyboer Tx weighs at least 7 pounds and then there's the choke and filiment Tx on top. All in all I have 12-13 pounds of iron sitting on top......Colin
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| Re: I like it [message #30644 is a reply to message #30640] |
Tue, 22 February 2005 14:04 |
Skip Pack
Messages: 51
Registered: May 2009
Location: Hollister, California
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Baron |
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The funny thing was that I used the sheet foam packing material that
came in the Foreplay kit. When we make up our top plates, assuming
that we're doing the hacking, boring, punching, and drilling ourselves,
it's virtually as easy to make a double set of plates for the
sandwich. My wife has a cheap source of copper (around 15 gauge,
I guess). The art department at our local community college buys
large sheets for the printmaking class, and has the big shear to cut it.
The cost is very low in comparison to anything commercial that
includes a cutting charge.Skip
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| Re: I like it [message #30646 is a reply to message #30644] |
Tue, 22 February 2005 20:06 |
colinhester
Messages: 1349
Registered: May 2009
Location: NE Arkansas
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Illuminati (3rd Degree) |
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It's pretty amazing how inexpensively one can do projects if just materials are factored in. I still really like the idea of using two top plates with insulation between. Right now the problem I'm running in to is that the 20ga copper palte I'm using is anything but quite. It's going to take a considerable amount of damping to quite it down. That's awesome you have a source of heavy gauge copper to play with. The one thing I do, however, like about the thinner ga is that it is easy to work with. It can be scored and cut with a sharp utility knife. And thanks to the guys over at the craftsman forum, I now know holes can be cut with a wood hole saw. Does your wife teach printing at the CC? I worked in the printing industry making inks (Flint Ink) for several years.....Colin
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