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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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29th Nov 2021, 8:01 pm | #1 |
Hexode
Join Date: Feb 2011
Location: Newcastle upon Tyne, Tyne and Wear, UK.
Posts: 280
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Hard wax on RF coil ferrite slugs
Could Otex ear drops dissolve the hardened wax which prevents the fragile slugs from rotating?
The active ingredient is urea hydrogen peroxide (5% w/w). The other ingredients are 8-hydroxyquinoline and glycerol Not sure if this could damage the coil former. |
29th Nov 2021, 8:53 pm | #2 |
Octode
Join Date: Jul 2014
Location: Petersfield, Hampshire, UK.
Posts: 1,043
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Re: Hard wax on RF coil ferrite slugs
If you heat the slug with a soldering iron just enough to soften the wax I find that works ok
Cheers Pete |
30th Nov 2021, 7:01 pm | #3 | |
Hexode
Join Date: Feb 2011
Location: Newcastle upon Tyne, Tyne and Wear, UK.
Posts: 280
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Re: Hard wax on RF coil ferrite slugs
Quote:
It might be damaged or cracked it's difficult to tell but the radio (Phiips 310A) is functional now, I'm not sure if it can be improved upon. I may well leave it as it is. |
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30th Nov 2021, 8:06 pm | #4 |
Dekatron
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 4,935
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Re: Hard wax on RF coil ferrite slugs
As a chemist, my instinct is that Otex is not the way to go, but I could be wrong. Are you really sure the stuff is wax and not something else like paint? Waxes tend to have 'modest' melting points.
Can you offer some more details on the formers? Are we talking IF coils, are they plastic or something else, what era are they. As you say, any approach needs to avoid damage to the formers. Wickes do a paint and varnish remover which I have used successfully to soften various substances with (in the process of cleaning), and I suspect it would soften (real) wax, but I know that it does react with some plastics. B
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Saturn V had 6 million pounds of fuel. It would take thirty thousand strong men to lift it an inch. |
30th Nov 2021, 8:37 pm | #5 | |
Hexode
Join Date: Feb 2011
Location: Newcastle upon Tyne, Tyne and Wear, UK.
Posts: 280
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Re: Hard wax on RF coil ferrite slugs
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30th Nov 2021, 8:57 pm | #6 |
Dekatron
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 4,935
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Re: Hard wax on RF coil ferrite slugs
Why don't you get a sharp knife and lift of some of the excess wax which is on top of the can and experiment with it? If it doesn't melt at some reasonable temperature (<100'C), that would be off-putting, tending to suggest it is a material which has set and may need a strong solvent to soften it.
B
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Saturn V had 6 million pounds of fuel. It would take thirty thousand strong men to lift it an inch. |
30th Nov 2021, 8:58 pm | #7 |
Triode
Join Date: Nov 2021
Location: Leighton Buzzard, Bedfordshire, UK.
Posts: 32
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Re: Hard wax on RF coil ferrite slugs
Never mind moving the stuck slug.
Add another ferrite slug and see if you can peak the coil. Leave it in if that works. If the output goes down there is a need to reduce the inductance. Introduce a small piece of brass or aluminium rod into the former and see if it peaks, glue that in if it does. If nothing peaks the coil then the existing slug is in exactly the right place. This may not work with TV IF coils where the core affects coupling.
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John |
30th Nov 2021, 9:02 pm | #8 |
Dekatron
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 4,935
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Re: Hard wax on RF coil ferrite slugs
Curious that on the two transformers to the right, the slugs seem to be on brass screw shafts, but the coil that's highlighted is different.
B
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Saturn V had 6 million pounds of fuel. It would take thirty thousand strong men to lift it an inch. |
30th Nov 2021, 9:53 pm | #9 |
Pentode
Join Date: Nov 2020
Location: Bristol, UK.
Posts: 132
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Re: Hard wax on RF coil ferrite slugs
Further to reply from John (Sundog) "back in the day" there was a device like a pencil called a Tuning Wand which had exactly what he described ie a ferrite slug at one end and a brass slug at the other.
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2nd Dec 2021, 1:24 pm | #10 | |
Hexode
Join Date: Feb 2011
Location: Newcastle upon Tyne, Tyne and Wear, UK.
Posts: 280
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Re: Hard wax on RF coil ferrite slugs
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