marv
:Hey hi ...I woul dlike to unwind and rewind audio interstage transformers....Yah..I know it will be a three day project...any good ideas....I have the good old three dialer sets with bad transformers and want to unwind fix breaks and rewind..Any good set ups for this??
I would advise against going into this half-hearted. It is generally not wise (and, ultimately, extremely frustrating) to simply look for and try to fix a break in a winding. Oftentimes, there are multiple breaks and corrosion (perhaps related to acid solder flux used before we knew better!) - along with the fact that you would be working with 70 to 80 year old frog-hair wire in some cases. If you are going to do it - plan on learning how to do it properly - which, most times, will require a complete rewinding with fresh wire.
On the other hand, if you are simply looking to get the radio playing for your own enjoyment in limited use, you can try this temporary fix. Attach a neon sign transformer to the faulty winding for no more than a couple of seconds - disconnect and test with an ohmeter to see if you get continuity in the winding. Repeat as necessary until you get some continuity - but, usually, if there's no response after 2 or 3 attempts - it won't work. I have "repaired" a number of open transformers in this manner that are still working years later. The theory is that you are "welding" some of the windings together near the breaks - or, at least, forming a carbon trace to the ends of the breaks. By no means will it perform as good as a rewound or replacement transformer - but many times the difference to the ears is negligible.
:"I have the good old three dialer sets with bad transformers and want to unwind fix breaks and rewind..Any good set ups for this??"
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:I would advise against going into this half-hearted. It is generally not wise (and, ultimately, extremely frustrating) to simply look for and try to fix a break in a winding. Oftentimes, there are multiple breaks and corrosion (perhaps related to acid solder flux used before we knew better!) - along with the fact that you would be working with 70 to 80 year old frog-hair wire in some cases. If you are going to do it - plan on learning how to do it properly - which, most times, will require a complete rewinding with fresh wire.
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:On the other hand, if you are simply looking to get the radio playing for your own enjoyment in limited use, you can try this temporary fix. Attach a neon sign transformer to the faulty winding for no more than a couple of seconds - disconnect and test with an ohmeter to see if you get continuity in the winding. Repeat as necessary until you get some continuity - but, usually, if there's no response after 2 or 3 attempts - it won't work. I have "repaired" a number of open transformers in this manner that are still working years later. The theory is that you are "welding" some of the windings together near the breaks - or, at least, forming a carbon trace to the ends of the breaks. By no means will it perform as good as a rewound or replacement transformer - but many times the difference to the ears is negligible.
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I am full aware of all that ...but thanks.
http://antiqueradios.com/forums/viewtopic.php?t=104695
rewinding is not an easy task. you would most likely have to replace the wire. the main things you ned to know about the windings are as follows, 1- wire size or guage, 2- number of turns. i used to rewind motors. that was not a real easy task. the old varnish needs to be removed with out destroying the core and windings. rewinding transformers are even togher. your best bet would be to take the x-former to a company that rewinds them. the problem with x-formers are counting the windings. on a motor you just cut off one end of the windings and count the turns. in a x-former you cant do that to easely. then after rewinding, you need to varnish and bake it.
::Check out this discussion on the Antique Radio Forum:
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::http://antiqueradios.com/forums/viewtopic.php?t=104695
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:rewinding is not an easy task. you would most likely have to replace the wire. the main things you ned to know about the windings are as follows, 1- wire size or guage, 2- number of turns. i used to rewind motors. that was not a real easy task. the old varnish needs to be removed with out destroying the core and windings. rewinding transformers are even togher. your best bet would be to take the x-former to a company that rewinds them. the problem with x-formers are counting the windings. on a motor you just cut off one end of the windings and count the turns. in a x-former you cant do that to easely. then after rewinding, you need to varnish and bake it.
It's a rather different skill. At any rate, the winder I mentioned in my Antique Radio Forum post is simply a shaft running in ball bearings with a worm gear driving a three-digit counter through a 100-turn gear (it counts thousands, hundreds and tens). The shaft is belt-driven by a variable-speed DC motor. For counting turns on the old winding, you attach the coil to the shaft and pull the wire off, while the counter keeps track. It's tedious but easy enough to do. Photos of the winder, and the assortment of mandrels to fit various coils, were posted previously in the Forum but I would have to search there to find them. I can email photos to anyone who wants to see them (adouglas at gis.net).