From: legg@nospam.magma.ca   
      
   On Sat, 8 Nov 2025 09:40:22 +0000, liz@poppyrecords.invalid.invalid   
   (Liz Tuddenham) wrote:   
      
   >Jan Panteltje  wrote:   
   >   
   >> >Bill Sloman wrote:   
   >> >>On 8/11/2025 6:23 am, Jan Panteltje wrote:   
   >> >>> liz@poppyrecords.invalid.invalid (Liz Tuddenham)wrote:   
   >> >>>> Bill Sloman  wrote:   
   >> >>>   
   >> >>>> On 7/11/2025 10:41 am, john larkin wrote:   
   >> >>> [...]>   
   >> >>>>> A real inductor is a nightmare. Especially a long solenoid. Every   
   >> >>>>> turn inductively couples to every other turn with all possible   
   >> >>>>> coupling coefficients. Distributed capacitances will be similarly   
   >> >>>>> complex.   
   >> >>>>   
   >> >>>> This is ignorant nonsense.   
   >> >>>   
   >> >>> I suspect the ignorance is yours.   
   >> >>   
   >> >> John is largely right I have wound big RF coils (MHz) for my shortwave   
   >> >> transmitter for high power, several 100 W, on just a simple ceramic   
   >> >> former, since the sixties. The mil sets do the same, that is where I   
   >> >> got the idea.,   
   >> >>   
   >> >> Same for small cores,   
   >> >>   
   >> >>   
   >> >>> I worked for a company that built its reputation on the R.F. inductors   
   >> >>> it designed; these factors were among the many problems they tackled.   
   >> >>   
   >> >> I wind almost everything I need myself.   
   >> >   
   >> >Coil-winding machines make that relatively easy. When I worked in a lab   
   >> >that had one, I did too.   
   >> >   
   >> >The Cambridge Instruments coil-winding shop on the production line had   
   >> >some very experienced coil winders, and they could wind finer wire than   
   >> >I could without breaking it. Sometimes that mattered.   
   >>   
   >> Yes, I had some small defective motor with a coil with wire so thin I   
   >> could not handle it, could hardly see it. Was for the turntable in my   
   >> microwave, ordered a new motor, fixed. Water had gotten into that motor   
   >> (overcooking ;-) and burned a hole through several layers of windings.   
   >> Thinner than hair enamel coated copper.   
   >   
   >A motor like that can sometimes be salvaged by winding it with thicker   
   >wire and running it from a spare transformer*.  It's crude, but   
   >worthwhile if it saves an expensive piece of equipment.   
      
   Microwave 'stirring' motors are pretty generic, but unforgiving in   
   form and fit.   
      
   Once there's been a fire, the bobbin and terminations are rarely   
   recoverable.   
      
   Replaced for a few bucks plus shipping. I keep pull-outs as spares.   
      
   RL   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)