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N3DRB The Derb
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« on: October 12, 2009, 11:04:04 PM » |
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2.5" cap clamps for 4E27's - even got some good Laird finger stock to snap onto each one. this should work FB.
try em on in the morning.
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N2DTS
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« Reply #1 on: October 13, 2009, 09:01:46 AM » |
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They look like electrolytic cap mounts.
Should work, but might look odd.
Are you mounting the sockets below the chassis?
That helps cooling with the chimney effect, gives extra room, and helps with the shielding.
Brett
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N3DRB The Derb
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« Reply #2 on: October 13, 2009, 09:42:26 AM » |
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sockets are flush mounted to chassis bottom as of now, but I think I'll be mounting them on thick hole aluminum 5/16" spacers. It does not matter for the plain old HK tube as they have no air holes in the base for air to go anywhere - but the Eimac and RCA versions do and I have some of them now. At 2KV @135~150 ma I dont think the base seals will be an issue. Not enough scrote there to have the molten solder problem with the pins or anything.
I do have 2 little tiny cage blowers at the ready and I may just use 1 of them for that deck. The other is a larger Dayton job that needs to go on a higher power unit, a 2 hole HK. I dont think it would move enough air for a 4-400.
lemme model them and see how they look.
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WA1GFZ
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« Reply #3 on: October 13, 2009, 12:24:03 PM » |
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you need plenty of air through the socket holes or the heater pins will boil lead.
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N3DRB The Derb
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« Reply #4 on: October 13, 2009, 03:58:44 PM » |
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Frank, do you mean for he 4E27's as well? I know the 4-400's have to have it, but everything describes the 4E27's as radiation cooled.
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N2DTS
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« Reply #5 on: October 13, 2009, 06:35:17 PM » |
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I was thinking about non forced air cooled tubes, like say 811's.
If you mount the tube sockets on spacers below the chassis, and make the hole the tube goes into bigger than the tube base, air will flow from under the chassis around the tube and up, convection cooling....
Not talking about a huge hole...
Brett
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N2DTS
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« Reply #6 on: October 13, 2009, 07:21:32 PM » |
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Like this...
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W1RKW
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« Reply #7 on: October 13, 2009, 08:04:12 PM » |
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Derb,
When you clamp the tube bases, clamp the tube bases first then secure the clamps to the chassis otherwise you may risk unnecessary side to side stress on the tube pins and this should help center the clamp in relation to the tube and chassis in the event you have to swap tubes later on.
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Bob
W1RKW
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KM1H
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« Reply #8 on: October 13, 2009, 09:27:12 PM » |
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Like this... More than that. You need to have the full metal base sunk below at a minimum. The more you can get the visible internal grid lead entering into the glass out of sight the better the stability. Im talking 160-10M here so if its strictly for 75 layout isnt as fussy unless you decide to add bands later. I spend more time on 20M and higher than lower so Im fussy. Carl KM1H |
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N3DRB The Derb
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« Reply #9 on: October 13, 2009, 11:24:21 PM » |
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this thing will never see anything higher than 40.
I have another option: I have a septar socket with grounding springs. I may wind up drilling out the rivets and using them instead.
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w4bfs
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more inpoot often yields more outpoot
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« Reply #10 on: October 14, 2009, 02:40:46 PM » |
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Like this...
very sano ! ... I am curious about the red painted variable cap ... did it doppler shift ? |
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Beefus
O would some power the gift give us
to see ourselves as others see us.
It would from many blunders free us. Robert Burns
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N2DTS
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« Reply #11 on: October 14, 2009, 02:53:57 PM » |
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In the 3x4D32 rig?
Its some sort of corona dope high voltage insulating paint.
I must have had it in something before, that arc'd over....
Or I got it out of something that the PO had the same problem!
As it is, it takes 1200 volts plus modulation without problems.
Brett
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N3DRB The Derb
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« Reply #12 on: October 14, 2009, 03:32:03 PM » |
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I'm gonna do the grunt work on the speech amp/modulator deck for a few days. I ripped all the old wiring out yesterday. today wick the sockets out, and change the front 4 sockets to 4 pin ceramics for the 2/6 A3's and the hytrons.
got a MRI tomorrow, so not much happening for a day.
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KB2WIG
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« Reply #13 on: October 15, 2009, 11:05:30 AM » |
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" got a MRI tomorrow, so not much happening for a day. "
Good luck, and ask 'em if they have any pulls from da MRI machine....
klc
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What? Me worry?
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KM1H
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« Reply #14 on: October 15, 2009, 11:10:17 AM » |
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Yeah, I can always use a 3CPX800 or 1500 or even a YC-156! Not everything here is AM  Carl KM1H |
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