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Re: Again with the forms?



Original poster: "Barton B. Anderson by way of Terry Fritz <twftesla-at-uswest-dot-net>" <tesla123-at-pacbell-dot-net>

Hi Shad, 

I agree totally. I'm glad you posted this. Often times we nit-pik and to new
coilers it can be confusing. PVC and sonotube are both low cost and have been
used for many years with great success. There have also been a few failures -
let's not forget that either. But, the success rate far out-weighs the failures
and with the low cost makes both of these formers good to use. 

I, like many coilers, want to squeeeezzzzz every little bit of loss out of my
"system" - including the secondary form. If a coiler follows this philosophy,
then building a lowloss form is right in line with this thinking. New coilers
just need to realize that much of what we talk about on this list is "how to
reduce losses" and this post like most went that route. 

Take care, 
Bart 

Tesla list wrote: 
>
> Original poster: "sundog by way of Terry Fritz <twftesla-at-uswest-dot-net>"
> <sundog-at-timeship-dot-net> 
>
>  Hi all, 
>
>  Does the dissapation of the secondary really matter?  I use 1/4"thickwalled 
> PVC 2" pipe with my small test coils, and have seen no difference between it 
> and thin PVC.  I really can't justify the expense of an acrylic tube for a 
> big coil, where the power input is magnitudes greater than a small coil 
> (10kva polepig vs a 15/60NST?)  Sonotube has been proven to work well, so 
> long as it's dry and well-prepared. 
>   Now true, some forms are lousy at TC freqencies, and tend to carbon track 
> badly.  If you're going for every mm of power output, I could see the 
> expense being a bit more rationalised.  But for a beginner, or even casual 
> coiler, PVC works grand and is a whole lot cheaper (sometimes even the big 
> stuff is free for the asking).  Looking at the number of coils running PVC, 
> even the huge systems using 1/2" thick PVC, I can't see it being all that 
> horrible as a form.  HDPE is wonderful for a form, but at least for me hard 
> to find what I *want* (different than what's available). 
>
>   Besides, odds are I'll smoke the secondary anyway trying to get that last 
> bit of spark out of it.  If I really expected the form to smoke, I'd have a 
> few smaller forms ready so I can "re-cycle" the wire onto them. Usually the 
> wire gets messed up at the ends, leaving a thousand foot or so of good wire 
> on the form.  I have wound plenty of small 2" coils off of my "bad" 8" 
> secondarys.  They work fine, I just have to keep a rag on the wire to knock 
> off the polyurethane as I re-wind the coil. 
>
>  So I'm not denouncing expensive forms.  I'm just sayin' (mostly to the 
> newbies) that PVC works fine, and acrylic is not a necessity for a good 
> performing coil.  Does it help?  sure!  Less energy dissapated= more energy 
> to the streamers!  But for those struggling to get the $$ for the coil, the 
> white (and green) 4" PVC drainpipe (mine was $12 a 10' length I believe at 
> Home Depot) works fine after cleaning with acetone and maybe a light 
> sanding. 
>                                                                          
>   Just my $.02 
>                                                                          
>                   Shad 
> PS, Not tryin to open the whole can of worms again, this debate can be found 
> it the archives, several times, at www.pupman-dot-com