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Friend had a little to much FT8 fun, looking to replace or fix, looking for replacement details for the FT114 sized?Toroidal? ? thanks kelly
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How much power did it take?
Micky K1XH
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On 2023-02-02 11:00 PM, Kelly K7MHI via groups.io wrote:
Friend had a little to much FT8 fun, looking to replace or fix, looking for replacement details for the FT114 sized?Toroidal? ? thanks kelly
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100w all they got?told “hours of digital” like hours, non stop slow saturation effect.?
kelly
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digi-key has them for about $1.15
On Feb 2, 2023 8:00 PM, "Kelly K7MHI via groups.io" <kellykeeton@...> wrote: Friend had a little to much FT8 fun, looking to replace or fix, looking for replacement details for the FT114 sized?Toroidal??
thanks kelly
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Earl, what is “them” can you confirm a mix / part? Or the sku for that $1.15 item ?
kelly?
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Sorry about that ...the ferrite core FT114.
On Feb 2, 2023 10:00 PM, "Kelly K7MHI via groups.io" <kellykeeton@...> wrote: Earl, what is “them” can you confirm a mix / part? Or the sku for that $1.15 item ?
kelly?
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Kelly
Palomar has kits up to a kilowatt. Might fit in the old box or get a new box from the hardware store. 100 watts FT8 hours at a time requires a heavy duty UNUN.?
Bill N7EU
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Curious... Not too much experience with baluns... When they are like this is there a real necessity for replacement?
What is the failure mode?
windings burnt open or shorting?
Some kind of damage to the ferrite core?
Winding shorting to core?
Or it just looks bad?
I can understand if the burnt enamel coating allows the wire to short to the core which i think could have been eliminated if glass tape were used for insulation.
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Dave,
Yes I think in this case the enameled wire is toasted. I would expect arcing and shorting of the windings.
I think to damage the core you would have to run a lot more power to physically crack the core or damage the ferrites electromagnetic qualities although I am no expert in that aspect.
When I homebrewed my own UNUN or Baluns I used teflon coated silver wire and stacked at least two ferrites to make sure they did not get saturated with RF. Maybe someone more knowledgeable than me can comment.
Bill N7EU
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Thanks for input! They wanted to repair it possibly all the memories of QSO and the fun of the day as a trophy or learning to repair. I think another was purchased!
I also agree it would take more juice to cause issues with the mix composition effectiveness but, I was just assisting with confirming the ring mix value.?
yea there is other Baluns I hear ya! I collect them all! never be without a bag of antenna parts!?
73 Kelly k7mhi :)
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I always use Teflon sleeving on my window gs. I couldn't tell by looking at the picture if the core had cracked. I assumed that's why you wanted to "repair" it. if it was electrically ok and just looked bad..it probably still works as it's suppose to, unless there is arcing and if that's the case you need to fix the antenna that's causing the trouble and runn tbe power level for that balun. I also agree with the fellow that stacks two cores so it doesn't get as saturated. ...my 2 cents.?
On Feb 3, 2023 2:12 PM, Dave Robinson <kb7gp@...> wrote: Curious... Not too much experience with baluns... When they are like this is there a real necessity for replacement?
What is the failure mode?
windings burnt open or shorting?
Some kind of damage to the ferrite core?
Winding shorting to core?
Or it just looks bad?
I can understand if the burnt enamel coating allows the wire to short to the core which i think could have been eliminated if glass tape were used for insulation.
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The curie temp for type 43 ferrite material is 130 deg C. At this temperature the ferrite loses its magnetic properties. Judging from the appearance of that 9:1 it probably reached the curie temp and is toast now. If you have a nanovna and a 450 ohm resistor you could rewind it and check it with the resistive load to know if it was still working. With validation, I would worry the tuner was masking a bad UNUN.
Gary
Sent from Proton Mail for iOS
On Fri, Feb 3, 2023 at 17:06, William Martin via groups.io < cwfingertalker@...> wrote: Dave,
Yes I think in this case the enameled wire is toasted. I would expect arcing and shorting of the windings.
I think to damage the core you would have to run a lot more power to physically crack the core or damage the ferrites electromagnetic qualities although I am no expert in that aspect.
When I homebrewed my own UNUN or Baluns I used teflon coated silver wire and stacked at least two ferrites to make sure they did not get saturated with RF. Maybe someone more knowledgeable than me can comment.
Bill N7EU
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The core ferrite material is useless – it has a temperature at which its magnetic permeability changes permanently.? You can read about this on the Fair Rite website in a core datasheet. Cheers Colin VE3MSC ?
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From: [email protected] <[email protected]> On Behalf Of Dave Robinson
Sent: Friday, February 3, 2023 5:13 PM
To: [email protected]
Subject: Re: [ldgelectronics] RU-9:1 Unun Burnt up Replacement? Curious... Not too much experience with baluns... When they are like this is there a real necessity for replacement?
What is the failure mode?
windings burnt open or shorting?
Some kind of damage to the ferrite core?
Winding shorting to core?
Or it just looks bad?
I can understand if the burnt enamel coating allows the wire to short to the core which i think could have been eliminated if glass tape were used for insulation.
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Just as an aside, I have a Palomar Engineers 9:1 setup with an
inverted L. Five 16' ground radials, up 25' and the rest
horizontal. I'm constantly amazed at how well it works. I push 1
KW into it. It is rated for 1.5KW. 1000ProII put sees nothing
worse than 2.1:1.
Doug -- K0DXV?
On 2/3/2023 4:06 PM, William Martin via
groups.io wrote:
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Dave,
Yes I think in this case the enameled wire is toasted. I would
expect arcing and shorting of the windings.
I think to damage the core you would have to run a lot more power
to physically crack the core or damage the ferrites
electromagnetic qualities although I am no expert in that aspect.
When I homebrewed my own UNUN or Baluns I used teflon coated
silver wire and stacked at least two ferrites to make sure they
did not get saturated with RF. Maybe someone more knowledgeable
than me can comment.
Bill N7EU
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Putting all of this in a hermetically sealed plastic box isn't helping either...? Try a metal one so it can get rid of the heat.? Glue some heatsinks to it or whatever it takes.? There are better boxes out there.? That plastic box is about the worst thing to use.
On Fri, Feb 3, 2023 at 6:50 PM Doug Person < doug@...> wrote:
Just as an aside, I have a Palomar Engineers 9:1 setup with an
inverted L. Five 16' ground radials, up 25' and the rest
horizontal. I'm constantly amazed at how well it works. I push 1
KW into it. It is rated for 1.5KW. 1000ProII put sees nothing
worse than 2.1:1.
Doug -- K0DXV?
On 2/3/2023 4:06 PM, William Martin via
wrote:
Dave,
Yes I think in this case the enameled wire is toasted. I would
expect arcing and shorting of the windings.
I think to damage the core you would have to run a lot more power
to physically crack the core or damage the ferrites
electromagnetic qualities although I am no expert in that aspect.
When I homebrewed my own UNUN or Baluns I used teflon coated
silver wire and stacked at least two ferrites to make sure they
did not get saturated with RF. Maybe someone more knowledgeable
than me can comment.
Bill N7EU
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Larry
I agree. I used aluminum boxes for my projects. At the 100 watt level I always made KW versions of the transformers.?
This discussion got me to dig out my old Jerry Sevick “Transmission Line Transformers” book.?
Bill N7EU
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FT200-2 and Teflon coated 14 or 16 ga wire will solve his problem. Putting vent holes in the box will release the heat. They are easily found on EBay or Amazon.
Here is a reference page:?
73 Morgan NJ8M BS + MS + $2.98 = COFFEE Real Life Experience = Priceless, says the man who set his back yard on fire with a breadboard tuner loading a 160 meter inverted L with 1000 watts. LOL
On Thu, Feb 2, 2023 at 10:00 PM Kelly K7MHI via <kellykeeton= [email protected]> wrote: Friend had a little to much FT8 fun, looking to replace or fix, looking for replacement details for the FT114 sized?Toroidal??
thanks kelly
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I've been buying my "un" boxes at the hardware store.? 4"x4"x2" boxes, and you can fit a 240 size ferrite in them easily.? I also use one of those stepped drill bits?from harbor freight to drill the holes for the SO-239.
FT200-2 and Teflon coated 14 or 16 ga wire will solve his problem. Putting vent holes in the box will release the heat. They are easily found on EBay or Amazon.
Here is a reference page:?
73 Morgan NJ8M BS + MS + $2.98 = COFFEE Real Life Experience = Priceless, says the man who set his back yard on fire with a breadboard tuner loading a 160 meter inverted L with 1000 watts. LOL
On Thu, Feb 2, 2023 at 10:00 PM Kelly K7MHI via <kellykeeton= [email protected]> wrote: Friend had a little to much FT8 fun, looking to replace or fix, looking for replacement details for the FT114 sized?Toroidal??
thanks kelly
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I would decrease power on FT8 to about 70-80 watts unless you have a more substantial 9:1 unun. Check SWR frequently. That way you might preserve the radio finals longer too. Have fun with FT8! 73 de WI5O
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Earl Lizardi
Dave Robinson
LarryS
Morgan Bailey