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Author Topic: Homebrew step up transformer ?  (Read 2972 times)
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KI4THX
El' Guappo Ernesto
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It's 106 Miles To Chicago, We Got A Full Tank Of G


« on: August 07, 2013, 08:47:36 PM »

Ive been doing an AWFULL lot of reading here as of late. I have a few questions that hopefully will spur enlightening comments.

I recently read an article that mentions homebrew modulation transformers ( http://www.amwindow.org/tech/htm/tvtomod.htm ) .

A few nights ago I dug out an old really small 120/46 VAC transformer...separated the plates....stacked "E"s and "I"s together.....reinstalled around the coil....separated the "E"s from touching the "I"s with paper...and slapped it back together. I also Isolated the core from the case.

Did I in fact just make a 1:3 step-up modulation transformer and is this in fact a decent alternative for the homebrew inclined ?

I absolutely give faith in WA1HLR's article....but if its this simple (if it is indeed) why do I hear so much worry about mod transformers and where to find them ? Ive got a whole stack of TV iron laying around here.......I may retract the whole "TV transformer Cannon" Idea I had now....jeeze.

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It's 106 Miles To Chicago, We Got A Full Tank Of Gas, Half A Pack Of Cigarettes, It's Dark And We're Wearing Sunglasses.

HIT IT !
kb3ouk
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« Reply #1 on: August 07, 2013, 09:32:15 PM »

How much does the core weigh? A good rule of thumb is about 10 watts per pound for good bass response, so you should be able to figure out how much power it could handle. If most of them are like some of the power transformers I have, they weigh 5 pounds at the most, which means only about 50 watts of audio. If you use a modulation reactor and capacitor with that transformer, then you should be able to handle about 3 times as much power as you could with just the transformer.
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Clarke's Second Law: The only way of discovering the limits of the possible is by venturing a little past them into the impossible
KI4THX
El' Guappo Ernesto
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It's 106 Miles To Chicago, We Got A Full Tank Of G


« Reply #2 on: August 07, 2013, 09:50:30 PM »

Ahh hah, 10 watts per pound, gotcha ! This little guy I dissected might be 2 pounds, little bitty fella.

I DO have some rather large cores around here too. Some up to 50-60lb mark.

Im far behind many here on this forum, Im sorry if Im asking questions or bringing up topics that "have been covered here before" but scouring through pages and pages and pages of topics with all the chaff and debate is mind warping. A lot of what Im learning here, some may mistake as common knowledge and something they learned about "years" ago....but to me, its NEW and FRESH !!!!

Heck, let the AM live....help a FNG.
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It's 106 Miles To Chicago, We Got A Full Tank Of Gas, Half A Pack Of Cigarettes, It's Dark And We're Wearing Sunglasses.

HIT IT !
KI4THX
El' Guappo Ernesto
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It's 106 Miles To Chicago, We Got A Full Tank Of G


« Reply #3 on: August 08, 2013, 03:34:00 PM »

"chirp-chirp-chirp"

Those crickets are loud in here.
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It's 106 Miles To Chicago, We Got A Full Tank Of Gas, Half A Pack Of Cigarettes, It's Dark And We're Wearing Sunglasses.

HIT IT !
W7TFO
WTF-OVER in 7 land Dennis
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« Reply #4 on: August 08, 2013, 07:40:10 PM »

Here is some old dope that still applies:

73DG


* xfmr3.jpg (874.76 KB, 1700x2200 - viewed 403 times.)

* xfmr2.jpg (1186.49 KB, 2800x1700 - viewed 349 times.)

* xfmr1.jpg (1153.87 KB, 2800x1700 - viewed 345 times.)
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Just pacing the Farady cage...
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