Re: Terry's latest gap (fwd)

---------- Forwarded message ----------
Date: Mon, 27 Jul 1998 12:40:44 +0300
From: Marco Denicolai <marco-at-vistacom.fi>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Terry's latest gap (fwd)

At 20:52 26/07/98 -0600, you wrote:
>I have built a couple of gaps just recently.  First stoped working
>properly, so built one along the lines of Terry's.  (30 gaps of 0.25 mm =
>10 mil).  Worked really well initially.  Did get quite hot, so placed my
>trusty fan nearby.  All OK.
>But then ........ set fire to wood base, as had placed rows of tubing too
>close together, and while the distance was > 2x the summed gaps for the
>desired path, still got flames :-(
>I suspect this relates to the field concentration at the ends of the tubes
>..... so in the interests of others not making the same errors as me.  If
>you make a TFG  ( I figure since we have RQG's, we may as well imortalize
>Terry as well !) , make sure the spacing between rows of tubing is
>sufficient !!!!!
>Next.  My gaps are 2..5 x greater than Terry's and the performance of my gap
>steadily declined with use.  On inspection, there was BRIDGING
>carbon/copper oxide in many of the gaps.  While this did not form a short
>circuit, it no doubt does decrement the quenching ability of the gap.
>Anyone with similar experience ??   (especially Terry ??)

Also I tried (after reading Teryy's mail) gaps of 0.25 mm inside a RQ gap.
The copper got extremely hot and also I got bridging.

The reason is that my tank can supply easily 0.25 A and that is a little too
much compared with the usual 60 mA.

After going to much safer 0.5 mm gaps (works, no bridging) I am now building
a rotating spark gap.


 Marco Denicolai                   Vista Communication Instruments, Inc.
 Hardware Development Manager      www.vistacom.fi   

 marco-at-vistacom.fi                 Kaisaniemenkatu 13 A
 fax:    +358-9-622-5610           SF-00100 HELSINKI
 phone:  +358-9-622-623-15         Finland

   Remember, Murphy was an optimist! I am not...