Re: Can anybody ID these caps?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <Mddeming-at-aol-dot-com>

In a message dated 4/22/01 10:43:36 AM Eastern Daylight Time, 
tesla-at-pupman-dot-com writes: 


>
> Original poster: "jpeakall by way of Terry Fritz <twftesla-at-uswest-dot-net>" < 
> jpeakall-at-mcn-dot-org> 
>
> I have some ceramic looking doorknob caps, marked: 
>
> N4700 
> 701M 
> M (The M is in  a circle) 40kv 
> 507A 
> they test out to .007pf 
>
> I have been using these on a small coil with an OBIT, and they have never 
> gotten warm. I just got a 15kv 60ma NST (for 20$ with 20' of 15kv wire, 
> sweet!), and am wondering if these caps can handle the NST. 
>
> Thanks 
>
> Jonathan 


Hi Jonathon! 

      IThey sound similar to the ones I used with an OBIT-powered coil. Mine 
look like white glazed hockey pucks" about 2.5" dia x 0.6" thick.They say 
401M and are 0.004uF+-10%. I'm assuming your 0.007pf is a typo? They worked 
well, but they don't like overvolting. (i.e., use a safety gap across them.) 
The ceramic is such a good insulator, that by the time the outside feels hot, 
the inside dielectric is approaching magma consistency ;-)) For me, they were 
a little pricey $25.00 + S&H and my supply dried up before I could get any 
more. 

Matt D.