[Amps] Cleaning air-wound coils

[John Wilson]

Has anyone done any tests on the comparative Q between Silver plated, 
enamelled and tinned wire coils?  I've always felt that factory  
enamelled wire stood a much better chance of retaining a good Q for a 
long time as the surface of the copper should still be pristine under 
the enamel.  The other question is how long the enamel will last if used 
at high temperatures.  Carbonised enamel is probably worse than 
tarnished tin!

John G3UUT

Ron Youvan wrote:
> Ron Youvan wrote:
>
>   
>>  >> How do you get the tarnish off of miniductor or airdux-type coils wound
>>  >> with tinned wire?
>>     
>
>   
>>> The problem is keeping it looking fresh without affecting performance. 
>>> Maybe a very light coat of clear acrylic if the RF doesn't get them 
>>> too warm.
>>>       
>
>   
>>> If you're real talented maybe a fast dip in a solder pot after 
>>> cleaning or even silver plating.
>>>       
>
>   
>>   I think part of the problem with these coils is frequently the thin 
>> tin coating is scratched and rubbed off.  (copper shows through) A real 
>> good cleaning followed by one of the "cold tin" platings would restore 
>> the original look.  (lacking a silver coating)
>>     
>
> After thinking about miniductor coils I realized:    (skin effect)
> metal			resistivity
> silver			106
> copper			100 annealed
> copper			89.5 hard drawn
> gold			65
> tin			13
>
>    this makes me think the tin coated miniductor coil material is a very bad idea when it 
> comes to high power  from:  www.wisetool.com/designation/cond.htm
>