N2DTS
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« Reply #25 on: January 14, 2009, 03:48:54 PM » |
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Yep, thats what I have.
I have a bunch, I should collect them at work, a lot must have went out in the trash...
Brett
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k7yoo
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« Reply #26 on: January 14, 2009, 05:43:45 PM » |
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Run a high value resistor from the core to ground if you decide to insulate the transformer. There may be a charge developed that can get fairly high if you don't. N4VMY (RIP) & W9OTN clued me in to this many moons ago. I personally don't understand all of the hoopla about transformer insulating. In the 30 or so commercial /military transmitters I have owned I have yet to see one mounted this way. I admit I have done it, but mainly to cover up what's under the tranny. The new Peter Dahl iron is FB stuff and doesn't need the babying. A wimpy SNC or used iron of unknown pedigree might be a different story.
2 cent Skippy
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Detroit47
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« Reply #27 on: January 15, 2009, 09:33:23 AM » |
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This doesn’t apply to your situation exactly. A source for thick cheap insulator is those plastic cutting boards for veggies. I have cut them up for tesla coil projects. Also when working on dielectric processing equipment. We use a lot of stand off’s and insulators mainly Teflon. Any insulators we use near RF go for a ride in a microwave. If they get hot or even warm they go in the trash. I have found that ceramic insulators have a tendency to explode at 10 KV and up. This has happend when there is RF on the DC. and is usually on the order of 20kw. We used 30MHZ of RF to dialectically bond fabric for inflatable buildings. Also for bonding and embossing the vinyl door panels on cars.
73 Johnathan N8QPC
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WA1GFZ
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« Reply #28 on: January 15, 2009, 12:04:44 PM » |
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Derb gets my vote. Why JS a beautiful rig
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flintstone mop
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« Reply #29 on: January 15, 2009, 01:47:23 PM » |
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Those Glastic things look like lightning protection stuff we used in our microwave tower sites. The old Halo ground concept..
Leave it up to DERB to come up with "heavy duty"
Phred
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Fred KC4MOP
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WA1GFZ
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« Reply #30 on: January 15, 2009, 02:35:49 PM » |
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We use them at work. First rate looking.
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N3DRB The Derb
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« Reply #31 on: January 15, 2009, 04:56:24 PM » |
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thats what hey are used for. they isolate ground buss bars with them. I used 6 here, got one left I gotta match up this hmfest season. you put 5/8" grade 8 SS hardware in those holes and nothing goes anywhere. You size them to the need, you could tip a 150 pound plate xformer on its side and mount it that way in the cab if you really wanted to.  |
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WA1GFZ
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« Reply #32 on: January 16, 2009, 11:21:26 AM » |
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We have a box that has welding cable feeding it at 650 DC. They used them all over the inside. It is a beautiful thing.
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AB2EZ
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"Season's Greetings" looks okay to me...
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« Reply #33 on: January 16, 2009, 11:56:02 AM » |
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Brian
I had a lot of audio feedback from my KW-1... caused by the mod transformer, resonating with the KW-1 cabinet.
To solve the problem, I removed the bolts that held the mod transformer to the cabinet, and I placed a 1/4" thick computer mouse pad under it. It is held in place by gravity... and it has worked fine (drastically reduced the acoustic feedback problem) since I did that several years ago
Your home brew modulator is beautiful!
Best regards
Stu
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Stewart ("Stu") Personick. Pictured: (from The New Yorker) "Season's Greetings" looks OK to me. Let's run it by the legal department
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k7yoo
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« Reply #34 on: January 16, 2009, 02:43:27 PM » |
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Stu, AB2EZ has come up with one of the few good reasons to "insulate" the mod transformer. KW1, BC 610, etc.all have the talking problem--mouse pad is a great fix.
Skip
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WA1GFZ
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« Reply #35 on: January 16, 2009, 02:46:29 PM » |
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4 insulated shock isolators would be cool in that application.
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N3DRB The Derb
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« Reply #36 on: January 16, 2009, 04:53:11 PM » |
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I'd just put those wide neoprene washers on the Glastics, top and bottom.
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WA1GFZ
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« Reply #37 on: January 16, 2009, 04:56:50 PM » |
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Na, you want a $200 mil isolator on each corner.
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W1VD
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« Reply #38 on: January 16, 2009, 06:06:57 PM » |
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www.mcmastercarr.comcheck out page 1350 ... Vibration-Damping Mounts
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'Tnx Fer the Dope OM'.
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WA1GFZ
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« Reply #39 on: January 16, 2009, 09:27:29 PM » |
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Derb has a good idea. Just use a longer screw so it bottoms out and the washers are not compressed. A metal washer between the transformer and top soft washer.
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N3DRB The Derb
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« Reply #40 on: January 30, 2009, 05:18:27 AM » |
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they'll never break or fail. go to home depot and get the wide neoprene washers and SS hardware (flat split & screw) to match and you R set for life. How much did they cost you? I got mine for 50 cents each at a fester, so I dont know what they go for new.
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