Neon Update.

Subject:  Neon Update.
  Date:  Fri, 13 Jun 1997 05:49:27 -0700 (PDT)
  From: gweaver <gweaver-at-earthlink-dot-net>
    To: Tesla-at-pupman-dot-com

About a month ago I put several shorted neon transformers in the kitchen
oven long enough to melt the tar to liquid.  When the neons cooled I
them and they worked fine again.  Before I put the neons in the oven I
removed the top cover and looked inside.  All the neons had cracks in
tar.  Age must have caused the tar to dry out and crack.  After removing
neons from the kitchen oven I removed the covers again and looked inside
found no cracks in the tar.  

I put 3 of these neons in parallel on my TC.  I made sure the 3 neons
matched.  I connected a 1000 ohm resistor between the HV terminals of
1st and 2nd neons and turned them on.  A large voltage difference would
the resistor and a small voltage difference would make the resistor get
warm. After about 1 minute the resistor was still room temperature.  I
another voltage match on the 2nd and 3rd neon and the resistor didn't
warm here either.  With 12K 90 ma I am getting 45" sparks from my 6"
The TC has been setup on the work bench for several weeks and I turn it
almost ever day for 5 or 10 minutes.  Almost every weekend someone comes
over to see the TC and the run time on weekends is 30 minutes to 2 hours

These neons are holding up well.  I had about 5 minutes to 2 hours of
time on these neons when they shorted out.  Now the same neons have run
about 18 hours without shorting out again.  This makes me wonder if the
dryed out cracked tar in old neons contribute to them shorting out. 
it would be wise to put all old neons with cracked tar shorted or not in
oven and melt the tar.  

I had one shorted neon with tar so dried out that it refused to melt in
oven at 300 degrees.  The tar did get very soft so I scrapped it all out
the case and mixed about 1/2 cup of high voltage transformer oil with
tar to make it liquid again.  I poured the tar back into the neon case
put it in the kitchen oven for an hour to melt so it would fill up all
spaces.  Now the neons is working fine again.  I have been giving it a
out and it hasn't shorted out yet.

Gary Weaver